165971387-SAP-Modeling-a-Building-Structure.pdf

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SAP2000 Seminar

Session 02

Modelling a Building Structure B Ald P l B lili MSCE

By Alden Paul Balili, MSCE DRBENGS, DLSU

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Prerequisites

q

• Should have taken Session 1 !

Should not be afraid to make mistakes

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Initial Model

• Assuming you have learned something in Part 1, model the 4 story structure described in the next model the 4 story structure described in the next slides.

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2

nd

_{t 4}

th

_Fl

2

nd

_{to 4}

th

_Floor

6m 6m 6m 6m fc` 21 Mpa 4 @ 1m typical C1 C1 C1 fc =21 Mpa fy = 275 Mpa Ec = 21500 Mpa Unit Weight of 5m yp C1 C1 C1 Concrete = 24 kN/m3 d _Fl _B 5m C1 C1 C2 _C2 _C2 2nd _{Floor Beams} 400x250 The rest 400x200 _5m C1 C1 C2 C2 _C2 400 00 C1 500x300 C2 400x400 5m C1 C1 C1 C1 C1 C1

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R f L

l

Roof Level

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El

ti

Elevation

Roof 3m h _l Roof 3m 4th _Floor 3m 3rd _Floor 3 2nd _Floor 3m

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SAP2000:

Slanted Grids

• For this structure it would be very helpful if For this structure it would be very helpful if we have slanted grids.

• Let us create a new structure with 5 X grids, id d Z id

4 y grids and 5 Z grids. _{As much}

possible make initial spacing t t l near to actual

Never forget to

change this prior to making a new model

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SAP2000:

Slanted Grids

• Initial GridlinesInitial Gridlines

This gridline to be

converted to a slanted one converted to a slanted one

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SAP2000:

Slanted Grids

• To Convert Standard grids to slanted ones we must first To Convert Standard grids to slanted ones we must first convert the system to a general system

• To convert to a general system go to Define > Coordinate

S /G id

Systems/Grids

• Check “Convert to General Grid” (warning: this couldn’t be undone!))

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SAP2000:

Slanted Grids

• From the Grids, we need to edit Grid 4. Click Grid 4, then From the Grids, we need to edit Grid 4. Click Grid 4, then click Modify/Show Grid Line

• For the Y2 put “+4” after 15

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SAP2000:

Slanted Grids

• Click ok again in the “Grid System Data Window” and the Click ok again in the Grid System Data Window and the next window after that

• Notice that some gridlines don’t have an intersection. Let b k d di h id

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SAP2000:

Slanted Grids

• Alternatively, you could double click a grid and edit its Alternatively, you could double click a grid and edit its properties

• Double click any part of gridline A First

• Choose Gridline A and click Modify/Show Grid Line

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SAP2000:

Slanted Grids

• Notice that gridline A has been extended.Notice that gridline A has been extended.

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SAP2000:

Defining Concrete Sections

• Now let us define the concrete sectionsNow let us define the concrete sections

▫ Go to Define Menu > Section Properties > Frame Sections ▫ Add a New Property

Ch C d R l

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SAP2000:

Defining Concrete Sections

• In the section properties input the following for C500x300 In the section properties input the following for C500x300 Column

• Notice that we haven’t defined concrete materials yet. You ld li k h i i h i l dd

could click the + sign in the material part to add one

As per properties properties specified at the start of this presentati on

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SAP2000:

Defining Concrete Sections

• Choose the appropriate material before clicking okChoose the appropriate material before clicking ok

• Note that there is reinforcement indicated in the section.

• This reinforcement is used for design purposes only and will not affect the area and moment of inertia of a section

’ l h Let’s leave the

reinforcement as is for now

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SAP2000:

Defining Concrete Sections

• Now do sections for the followingNow do sections for the following

▫ B400x250 (B indicates Beam) ▫ B400x200

▫ C400x400 (C indicates column) ▫ C400x400 (C indicates column)

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SAP2000:

Drawing Frames in 3d

• Now let’s draw the columns on the 1_{Now let s draw the columns on the 1 floor}st _floor

• The problem with generalized grids is that the XZ and YZ can not be accessed anymore.

• Let us hide the gridlines from Storey 2 to 4

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SAP2000:

Drawing Frames in 3d

• The grids would look like as shown belowThe grids would look like as shown below

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SAP2000:

Drawing Frames in 3d

• All columns have been drawnAll columns have been drawn

Remember that the columns have different sections!

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SAP2000:

Drawing Frames in 3d

• Now Let us draw the beams in planNow Let us draw the beams in plan

• Go to plan view and draw all beams as shown below on story 1. Use 400x250 Section

Shrink the objects for convenience!

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SAP2000:

Drawing Frames in 3d

• Set the View Limits to allSet the View Limits to all

• Now go to 3d View again and select all objects

• Go to Define Menu > Replicate. Replicate 3 times upward with dz = 3m

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SAP2000:

Drawing Frames in 3d

• Now go to the plan view of the uppermost level and delete Now go to the plan view of the uppermost level and delete the beams are not in the model

• If you made a mistake, go to Selection Menu >Clear

S l i if l h l i

Selection if you want to clear the selection

2 Beams can be selected by using an “exclusive window”. S f i t 1 Sequence of points indicated

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SAP2000:

Extra: Selection

• Clicking all desired elements is a cumbersome

• Clicking all desired elements is a cumbersome exercise.

• Alternatively we can window the whole story to

select all beams. However, this method also selects the other objects.j

• Notice the selected objects in the lower left corner

Note that 40 lines are selected. Where did this come from? Where did this come from?

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SAP2000:

Extra: Selection

• The extra lines selected comes from the columns

• The extra lines selected comes from the columns. They are selected by this “window all” method.

• If we want to select beams only we have to do

• If we want to select beams only we have to do another type of window, the “exclusive” window. Note the differences below

Inclusive Window

Drag from Left to right

Exclusive Window

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SAP2000:

Extra: Selection

• An inclusive window only selects objects that

are inside the window.

• For an exclusive window an object will be

• For an exclusive window, an object will be

selected as long as any portion of that object is inside.

Inclusive Window

Drag from Left to right

Inclusive Window

Drag from Right to left

Selected Not selected

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SAP2000:

Supports

• To assign supports let us go to the plan view of the baseTo assign supports let us go to the plan view of the base

• Do a window selection covering the whole structure

• Go to Assign > Joints > Restraints

• Choose fixed support and click ok!

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SAP2000:

Model Finished?

• Now we have the main parts of the structureNow we have the main parts of the structure

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Initial Model

• Finished?

However your boss forgot to tell you the

• However, your boss forgot to tell you the additional changes to the framing of the structure.

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Additional Members are dashed

Initial Model

• Finished?

However your boss forgot to tell you the

• However, your boss forgot to tell you the additional changes to the framing of the structure.

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Advanced Model Editingg

• Let us show the different ways to add members

in SAP2000 by showing techniques which are in SAP2000 by showing techniques which are best suited for each member

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Sap2000

Secondary Beams

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Sap2000

Secondary Beams

Th id h ld b h i d l b f

• The grids should be shown in your model before proceeding and go to plan view of storey 1

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Sap2000

Secondary Beams

T dd d b i kl j h

• To add secondary beams quickly just snap to the midpoints of the beams

• Use section 400x200Use section 400x200

Pressing right click Pressing right click when you are at this point breaks the line but doesn’t cancel

d d

Turn on midpoints draw mode

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Sap2000

Secondary Beams

l dd h b b d i

• Now let us add these members by doing a

combination of replicate, divide and delete commands

commands

1m

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Sap2000

Secondary Beams

li h b i d i

• Step 1: Replicate the members in red in accordance with the given dimensions

Dx = -1m

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Sap2000

Secondary Beams

l h b di

• Step 2: Select the two members. Go to Edit Menu > Edit Lines > Divide Frames

Choose the 2nd _{option and click ok}

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Sap2000

Secondary Beams

h b

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Sap2000

Secondary Beams

h d i d b b l i

• Step 4: Merge the desired members by selecting them then go to Edit Menu > Edit Lines > Join Frames

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Sap2000

Secondary Beams

N h d h b i h i

• Now we have done the beams without computing coordinates!

• Remove the shrink and you will see that there is a little Remove the shrink and you will see that there is a little portion of a member beyond the beam at the top

• This could be removed by using the same processes as did i th l t lid !

we did in the last slides!

Remove through the given steps!

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Sap2000

Secondary Beams

N h d h b i h i

• Now we have done the beams without computing coordinates!

• Remove the shrink and you will see that there is a little Remove the shrink and you will see that there is a little portion of a member beyond the beam at the top

• This could be removed by using the same processes as did i th l t lid !

we did in the last slides!

Remove through the given steps!

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Sap2000

Extra: Special Joints

Al i l i l j i

• Alternatively, we can use special joints to serve as “guides” for our new members

• First let us delete the member shown below.First let us delete the member shown below.

• Go to Draw Menu > Draw Special Joint

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Sap2000

Extra: Special Joints

Cli k h j i i di d b l

• Click on the two joints as indicated below.

• You will notice that SAP2000 has added dots indicating the “special” joints.

the special joints.

• Now you can use these joints to snap on to draw the additional beams

Dots indicating special joints Click these nodes

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Sap2000

Extra: Special Joints

Q Wh i l j i ?

• Q: What are special joints?

▫ These are joints that need to be drawn by the user and are not a result of drawing structural membersg

• Q: What are the common uses?

▫ Points where joint loads not at end of members are present ▫ Convenience of drawing of additional beams

▫ Convenience of drawing of additional beams ▫ Dividers of existing members

• Note: These special joints do not divide the member automatically during the modeling phase. However, the member which has a special joint will be divided at these joints prior to analysis.

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Sap2000

Secondary Beams

ddi i l b

• Additional Members

▫ Member shown below can be easily added by a

combination of replicate and draw lines command combination of replicate and draw lines command ▫ Do these members first

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Sap2000

Secondary Beams

ddi i l b

▫ However, members at the corner would need additional ETABS features we haven’t used yet additional ETABS features we haven t used yet

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Sap2000

Secondary Beams

ddi i l b

▫ Currently We have these members at the corners. Members to be added are in hidden line

Members to be added are in hidden line.

Top end of the Top end of the member must be moved because it is just a replication of this line

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Sap2000

Secondary Beams

’ll d h li h h d i d

• We’ll do these steps to accomplish the desired geometry

Extend the necessary lines so that they intersect ▫ Extend the necessary lines so that they intersect ▫ Split the intersecting lines

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Sap2000

Secondary Beams

d h li h h i

• Extend the necessary lines so that they intersect

▫ To do this use the Draw Menu > Reshape Element mode A small window will appear

mode. A small window will appear

▫ After this, click the member you want to edit.

Preferably on its midpoint. The member will now y p be dashed. Only one member can be reshaped at a time

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Sap2000

Secondary Beams

d h li h h i

▫ Let us explore each option for the reshape object. For the Drawing Control Type None Click and ▫ For the Drawing Control Type = None, Click and

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Sap2000

Secondary Beams

d h li h h i

▫ Now choose the Horizontal option and click and drag the top point

drag the top point.

▫ Notice the constraint in the movement

Can only be moved along x Can only be moved along x

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Sap2000

Secondary Beams

d h li h h i

▫ Vertical option is the same only this time the movement is constrained to the Y axis

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Sap2000

Secondary Beams

d h li h h i

▫ Parallel to angle option lets you constrain the movement in the angle of your choice

movement in the angle of your choice.

For this

example, 45 degrees

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Sap2000

Secondary Beams

d h li h h i

▫ Fixed length option lets you move the node within a given length It’s similar to the movement being a given length. It s similar to the movement being confined to circle with a specified radius

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Sap2000

Secondary Beams

d h li h h i

▫ Fixed length and angle let you just one point

decided by the angle in the circle mentioned in the decided by the angle in the circle mentioned in the last slide

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Sap2000

Secondary Beams

d h li h h i

▫ Fixed dh and dv lets you move a node to the desired x and y increment

desired x and y increment

dh dv

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Sap2000

Secondary Beams

d h li h h i

▫ Can you now figure out which lines to extend and what commands to use?

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Sap2000

Secondary Beams

d h li h h i

▫ Extend line 1 using the Vertical option

Extend line 2 using the Parallel to angle option ▫ Extend line 2 using the Parallel to angle option

Line 2

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Sap2000

Secondary Beams

d h li h h i

▫ Extend line 1 using the Parallel to Y option

Extend so that line is well beyond the expected ▫ Extend so that line is well beyond the expected

corner

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Sap2000

Secondary Beams

d h li h h i

▫ Extend line 2 using the Parallel to angle option. Extend beyond expected corner

Extend beyond expected corner. ▫ Input atan(1/6) = 9.46deg

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Sap2000

Secondary Beams

li h li

• Split the necessary lines

▫ Select the two lines that intersect.

Then select Edit Menu > Edit Lines> Divide ▫ Then select Edit Menu > Edit Lines> Divide Frames. Choose “Break at Intersections with

Selected lines and points”. Click ok when finished.p

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Sap2000

Secondary Beams

li d li h li

• Replicate and Split the necessary lines

▫ Delete the excess lines.

Do a combination of divide and replicate ▫ Do a combination of divide and replicate

commands so that you can see the configuration below.

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Advanced Model Editing

Adding Secondary Beams

h ddi i l b h b fi li d

• The additional beams have been finalized.

• Choose the new beams and replicate to the 3rd

and 4th _{floors (Store 2 to 3)}

and 4th _{floors (Storey 2 to 3)}

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Advanced Model Editing

Adding Secondary Beams

h b h f

• Remove the unnecessary beams on the roof

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SAP2000

Rotating the Axis of Members

b ildi i l f hi h

• For buildings, it usual for architects to have

columns aligned with the perimeter walls to add interior space

interior space.

• Let us rotate the columns below as per our architect’s preference

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SAP2000

Rotating the Axis of Members

Rotate by atan(1/6)o

Positive Rotation Direction

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SAP2000

Rotating the Axis of Members

Fi l “i l ” h l h h ld l

• First let us “isolate” the columns so that they could only be seen

• Select all columns by going to Select Menu > Select > Select all columns by going to Select Menu Select Properties > Frame Sections

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SAP2000

Rotating the Axis of Members

I d Vi ill h h l

• In 3d View you will see that the columns are now selected.

• To remove all other members from view right click on To remove all other members from view right click on any open space and choose “Show Selection Only”

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SAP2000

Rotating the Axis of Members

T h i i i i f h l l

• To see the existing orientation of the columns, let us go to a plan “3d View” of the structure

• Go to View Menu > Set 3d ViewGo to View Menu Set 3d View

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SAP2000

Rotating the Axis of Members

Af d i hi ill h i b l Y ld

• After doing this you will see the image below. You could notice that there is nothing

• To see the columns go to View Menu > Set Display To see the columns go to View Menu Set Display options

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SAP2000

Rotating the Axis of Members

N h i i f h l b S l

• Now the orientation of the columns can be seen. Select the upper columns as shown below. Through this

method you are actually selecting columns from top to y y g p bottom!

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SAP2000

Rotating the Axis of Members

P h f l ( /6) d h l ill b

• Put the formula- atan(1/6) and the angle will be computed. Click ok when done

• Remember if you made a mistake, you could go back to Remember if you made a mistake, you could go back to previous selection by going to Select Menu > Get

Previous Selection or press Ctrl+Z to undo

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SAP2000

Rotating the Axis of Members

N h i i l b d

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SAP2000

Creating Custom Sections

’ h hi f h b ildi h

• Let’s say the architect of the building wants the front columns to look like this.

100mm

What do you do???

300mm

100mm Symmetrical in both axes

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SAP2000

Creating Custom Sections

h i b ild i kl

• We can use the section builder to quickly compute the properties of this section!

100mm

300mm

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SAP2000

Creating Custom Sections

i fi

• To create a custom section go to Define Menu > > Section Properties > Frame Sections

Choose “Add Ne Propert ”

• Choose “Add New Property”

• Choose Other for Property Type and Click Section Designer

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SAP2000

Creating Custom Sections

h i d d h f ll i

• In the window do the following

▫ Apply an appropriate name (X500x300)

(X500x300)

▫ Choose the base material (CONC21MPa)

( )

▫ Design type: (No check/design) • Now we can click the “Section

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SAP2000

Creating Custom Sections

h i d i i f

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SAP2000

Creating Custom Sections

h i d i h f ’

• The section designer has many features. We won’t go deep into them.

For this e ample let us just use the “pol gon

• For this example, let us just use the “polygon draw” technique

• Polygon draw involves the following

▫ Draw the approximate shape of your section ▫ Change coordinates accordinglyg g y

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SAP2000

Creating Custom Sections

h l d li k h “

• To start the polygon draw, click the “Draw Polygon Shape” button on the left

The arro ill change indicating ou are in dra

• The arrow will change, indicating you are in draw mode.

• Draw the approximate shape of our cross Don’t

• Draw the approximate shape of our cross. Don t mind the scale

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SAP2000

Creating Custom Sections

h l d h d

• Once you have completed the 12 nodes, press

enter to complete the shape.

No e change the coordinates

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SAP2000

Creating Custom Sections

h h di

• To change the coordinates, go to Draw Menu > Reshape mode. You mouse cursor will again

change indicating you are in Reshape mode change indicating you are in Reshape mode.

• Click the shape, and notice the presence of dots at the corners

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SAP2000

Creating Custom Sections

ll d i h i

• Roll over your mouse on one node. Notice that it becomes a cross hair

Right click the node hen the cursor becomes like

• Right click the node when the cursor becomes like this. A window prompting the new coordinates

will appear Change the coordinate to (0 15 0 25) will appear. Change the coordinate to (0.15, 0.25)

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SAP2000

Creating Custom Sections

i h h i di h f

• Notice the change in coordinates? Do the same for the others. Coordinates for the corners shown as below

below _0.15,0.25

0.15, 0.15 0.25, 0.15

Change sign for other coordinates accordingly

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SAP2000

Creating Custom Sections

i i fi i h d li k d h

• Once your section is finished, click done on the lower right portion

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SAP2000

Creating Custom Sections

li k k h i i d f

• Click ok once you return to the main window of SAP

Click ok to confirm! Click cancel and everything is Your section is now in the list!

everything is cancelled!

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SAP2000

Creating Custom Sections

b k d l i d i h

• Go back to 3d plan view and assign the custom section to the columns indicated below.

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SAP2000

Creating Custom Sections

l h i

• Select then go to Assign Menu > Frame > Frame Sections . Choose X500x300 and click ok

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SAP2000

Creating Custom Sections

ill i h h li h l b

• You will notice that the outline has also been changed for the columns.

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SAP2000

Creating Custom Sections

d i

• Go to 3d View

• Now let us return the visibility of all objects by right clicking on an open space and chosing

right clicking on an open space and chosing “Show All”

Notice that it is still extruded Notice that it is still extruded. You can remove this by going to View Menu > Set Display Options

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SAP2000

Creating Area Elements

l d f h f ll i

• Area elements are used for the following

▫ Slabs and Decks for Flooring Walls for Retaining Walls

▫ Walls for Retaining Walls

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SAP2000

Creating Area Elements

F j l h ill C i i

• For our project let us assume that we will use Cast-in-situ slabs. Use 150 thickness.

• To create an area element go to Define Menu > Section To create an area element go to Define Menu Section Properties > Area Sections.

• In the window that appears choose “Shell” for type and li k “Add ti ”

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SAP2000

Creating Area Elements

h i d h f ll i

• In the window, enter the following

▫ Name: 150thkSlab

Material: Conc21MPa ▫ Material: Conc21MPa

▫ Thickness Membrane: 0.15 ▫ Thickness Bending: 0 15Thickness Bending: 0.15 ▫ Click ok when done

▫ Type: Shell Thinyp

It’s now added to the list Click ok to confirm! Click ok to confirm! Click cancel and everything is cancelled!

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SAP2000

Creating Area Elements

h d fi d l h l

• We have now defined our area element. The only

thing left to do is draw it.

Go to the plan ie of the 2nd _{floor/stor 1 Make}

• Go to the plan view of the 2nd _{floor/story 1. Make}

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SAP2000

Creating Area Elements

f d l h f ll i

• Before we proceed, let us note the following openings

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SAP2000

Creating Area Elements

d l b l

• To draw a slab, go to Draw Menu > Draw Poly Area

• A little window will appear which indicates some options for the drawing

options for the drawing.

• Choose the appropriate property before proceeding

Usually, this option is enough for drawing slabs!

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SAP2000

Creating Area Elements

li k h i i l k i ( i i

• Click these points in a clockwise manner (Doing it counter-clockwise is also ok!)

2 1 3 4 5 ₆ Slab Outline 7 8

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SAP2000

Creating Area Elements

i d l h

• Press enter once you are in node 8 to complete the slab!

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SAP2000

Creating Area Elements

h h h i k bj i d i i

• When the shrink objects is turned on, it is easy to determine where the slabs are!

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SAP2000

Assigning Area Loads

l d ll f h f ll i

• Area loads usually come from the following

1. Selfweight of the slab 2 Topping above the slab 2. Topping above the slab

3. Approximate weight of the CHB walls 4 Live Load 4. Live Load 3 4 2 1

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SAP2000

Assigning Area Loads

Wh l d d b i d f h l

• Why use area loads and area members instead of the usual trapezoidal lineloads?

1. Trapezoidal load method not present in SAP2000 1. Trapezoidal load method not present in SAP2000

2. Distribution effects of slab between beams considered 3. Trapezoidal load method too cumbersome when

li d ll applied manually

45o

Direction of Load Shown

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SAP2000

Assigning Area Loads

hi l h f ll i

• For this structure let us assume the following

1. Selfweight of the slab (already taken into account due to selfweight = 1 in load case definition)

due to selfweight = 1 in load case definition) 2. Topping above the slab (0.6 kPa)

3. Approximate weight of the CHB walls (1 kPa) 3. Approximate weight of the CHB walls (1 kPa) 4. Live Load (2.4 kPa, office)

3

4

2 1

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SAP2000

Assigning Area Loads

T i l d li k f h l b l i

• To assign area loads, click any part of the slab to select it

• Go to Assign Menu > Area Loads > Uniform (Shell)

• The assign area loads window will appearThe assign area loads window will appear

Dashed line

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SAP2000

Assigning Area Loads

h i f / f l d

• There are many options for area/surface loads. But we usually choose “Gravity” for gravity forces. For surface pressure from ater or ind Local 3

• For surface pressure from water or wind, Local 3 axis is usually used.

• For our example choose gravity for the direction

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SAP2000

Assigning Area Loads

h f ll i f d d

• Input the following for dead

▫ 0.6 + 1 = 1.6 kPa

Load Case Name: Dead ▫ Load Case Name: Dead

▫ Coord System: Global , Direction: Gravity ▫ Choose “Replace Existing Loads” optionChoose Replace Existing Loads option ▫ Click ok when finished

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SAP2000

Assigning Area Loads

b ill i di h l d h b

• A number will indicate that area loads have been assigned

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SAP2000

Assigning Area Loads

S l h l b i d I h f ll i f li

• Select the slab again and Input the following for live

▫ 2.4 kPa

▫ Load Case Name: Live (Create this if not existent)Load Case Name: Live (Create this if not existent) ▫ Choose “Replace Existing Loads” option

▫ Coord System: Global, Direction: Gravity ▫ Click ok when finished

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SAP2000

Assigning Area Loads

ld b i h l b i di i

• You could see a number in the slab indicating what magnitude of load you just assigned.

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SAP2000

Area Auto-mesh options

h h l d i i i

• Now we have the loads, it is important to

determine how the slab will connect to the beams. This is important because e dre the slab as one

• This is important because we drew the slab as one object only.

• If we don’t apply auto-mesh on the slab we will

• If we don t apply auto-mesh on the slab, we will have erroneous results.

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SAP2000

Area Auto-mesh options

l h l h l b h

• To apply an auto-mesh, select the slab then go to Assign menu > Shell/Area > Area Object Mesh Options

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SAP2000

Area Auto-mesh options

’ l h diff i

• We won’t explore the different options.

• Instead this training would just recommend a methodolog most appropriate for this situation methodology most appropriate for this situation

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SAP2000

Area Auto-mesh options

T h h l b l l h h i

• To mesh the slab properly, let us choose the options shown on the window below

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SAP2000

Area Auto-mesh options

T h h l b l l h h f ll i

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SAP2000

Area Auto-mesh options

h i h d h f ll i

• The options we chose does the following

▫ The slab will be divided on all the beams that crossing it (cookie cut)

crossing it (cookie cut)

▫ The shapes that will result will further be subdivided to 0.75x0.75 elements max75 75

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SAP2000

Area Auto-mesh options

b h i

• Sub Mesh Option

▫ If you put a certain width A, this means ETABS would mesh the area into max AxA elements

would mesh the area into max AxA elements.

▫ This value is subject to engineering judgment. The smaller, the more accurate the results but the ,

analysis takes longer.

▫ Up to engineer to determine this value. Usually i f

(116)

SAP2000

Area Auto-mesh options

li k k h f h fi i h d

• Click ok on the form when finished.

• A label will indicate that the mesh has been assigned

(117)

SAP2000

Analysis check for the mesh

• To see the sub-division, the structure should be analyzed.

• But before analysis we must replicate the area element we edited to the other floors

edited to the other floors.

• Select the slab, then replicate to the other floors.

• By replicating this floor, we save time by not needing to y p g , y g repeat the load and mesh commands.

(118)

SAP2000

Analysis check for the mesh

• After the analysis is finished, you will see how the slab is divided

Looks good? By doing this we are taking into account the distribution action of the action of the slab!

(119)

SAP2000

Analysis check for the mesh

• Since our model is not yet finished, let us delete the analysis first.

• Go to options menu > lock/unlock model.

• When prompted, click ok. The analysis results will

b d l d

(120)

SAP2000

Grouping

• In ETABS, the grouping of Beams and Columns is g p g automatic

• In SAP2000, we must assign them explicitly Let us assign the beam group

• Let us assign the beam group

▫ Select All B members

▫ Go to Assign Menu > Assign to Group ▫ Click add new group

(121)

SAP2000

Grouping

• Let us assign the beam groupg g p

▫ Name the group “Beams” and click ok

▫ Click ok again in the next window and the B members are assigned to the beams

(122)

SAP2000

Grouping

(123)

SAP2000

Grouping

• Now these groups can be selected through the selection g p g tools.

• Select the beam group by going to Select Menu > Groups Choose Beams and click ok This will select all beams!

• Choose Beams and click ok. This will select all beams!

(124)

SAP2000

Property Modifiers

• In SAP, properties like mass, area and moment of inertia can be overwritten. This is done through the frame property modifiers.

• One example of the application of this feature, is

th d ti i ff ti t f i ti

the reduction in effective moment of inertia

prescribed by the NSCP for concrete models. This takes into account the cracking in concrete

takes into account the cracking in concrete.

(125)

SAP2000

Property Modifiers

• Now let’s apply first the reduction for the beams.

• Select all beams through the selection tools.

• Once selected, go to Assign Menu > Frame > Property Modifiers

(126)

SAP2000

Property Modifiers

• Put 0.35 for Moment of Inertia about 3 axis to take into account cracking in the major axis.

• Click ok when done

2 axis = White

(Gray for presentation purposes)y p p p

i d

3 axis = Blue 1 axis = red

(127)

SAP2000

Property Modifiers

• Once done, a “PM*” label will be placed on all beams

(128)

ETABS

Property Modifiers

• Now select all columns and assign 0.7 for Moment

(129)

ETABS

Property Modifiers

• To clear the labels, go to Assign menu > Clear Display of Assigns

(130)

SAP2000

Earthquake Loads - Automated

• As with wind, Earthquake loads can be computed

manually and the loads applied as joint forces.

• ETABS has a convenient feature wherein it automatically computes Earthquake forces

(131)

SAP2000

Earthquake Loads - Automated

• 3 main things need to be defined for accurate EQ forces

▫ The Rigid Diaphragms ▫ The EQ constants

Th M S

(132)

SAP2000

Earthquake Loads - Automated

• Rigid Diaphragms

▫ What are rigid diaphragms?

Can you point out the rigid y p g diaphragm?

(133)

SAP2000

Earthquake Loads - Automated

▫ What are rigid diaphragms?

 Where mass is concentrated

 Rigid enough that axial deformation is negligible  Means by which lateral forces are distributed to the  Means by which lateral forces are distributed to the

(134)

SAP2000

Earthquake Loads - Automated

▫ Accidental eccentricity will be erroneous if rigid diaphragms not defined.

(135)

SAP2000

Earthquake Loads - Automated

• Rigid diaphragms

▫ Before proceeding, let us go to plan view of storey 1 Select all the corner nodes of the slab as shown below ▫ Select all the corner nodes of the slab as shown below ▫ Go to Assign Menu > Joint > Constraints

(136)

SAP2000

Earthquake Loads - Automated

▫ In the Assign/Define Constraints window, choose diaphragm for the constraint type

▫ Click Add New Constraint

▫ Edit the options as shown below ▫ Click ok to finish this diaphragmp g

This means Diaphragm for storey 1

(137)

SAP2000

Earthquake Loads - Automated

▫ Repeat the process for the diaphragms at storey 2 and 3.

 Go to plan view  Go to plan view  Select the nodes

(138)

SAP2000

Earthquake Loads - Automated

▫ Dots indicate the joints where the diaphragm constraint was applied

▫ Also shown is a conceptual illustration of a diaphragm constraint

(139)

SAP2000

Earthquake Loads - Automated

▫ Now apply the same methodology to each level which has a slab (storey 2 and 3)

▫ Right click a node to check diaphragm constraint assignment

(140)

SAP2000

Earthquake Loads - Automated

• Earthquake Constants

▫ Earthquake constants are defined in the load case definition.

▫ Let us first create a load case named “Eqx” with type “Quake” and Auto lateral as “UBC97” Quake and Auto lateral as UBC97 .

(141)

SAP2000

Earthquake Loads - Automated

▫ Once load is added, Select it then click “Modify Lateral Load”

(142)

ETABS

Soil profile type. Would have effect

ETABS

Earthquake Loads - Automated

Would have effect on magnitude of earthquake Seismic Zone Factor Depends on Direction and eccentricity of force Period T Factor. Depends on the location. 0.4 for majority of the Philippines Period, T

calculation, this will determine the magnitude of force D fi iti f th Ca and Cv automatically calculated if not user defined Definition of the

top and bottom story. Always

ensure that bottom coordinate is zero

Seismic source type and distance to source. Will affect magnitude of the Response earthquake Na and Nv factors computed automatically if not Response modification factor, prescribed by NSCP for each type of frame

automatically if not user defined

(143)

SAP2000

Earthquake Loads - Automated

▫ For our example let use the data shown below

As prescribed by the NSCP 208 5 6 Soft Soil Zone 4 as per the NSCP 208.5.6 NSCP 208 5 2 2 Zone 4 as per NSCP 2001 Figure 208-1 NSCP 208.5.2.2 RC Frames S i l M Click ok once everything is f h d Special Moment Resisting Frame NSCP Table 208-11 finished

(144)

SAP2000

Earthquake Loads - Automated

▫ Once you have done this, no additional assignments need to be done. ETABS will compute the selfweight of the structure and the lateral EQ loads.

▫ But first let us do the earthquake loadcase in the y ▫ But first, let us do the earthquake loadcase in the

(145)

SAP2000

Earthquake Loads - Automated

▫ Eqy loadcase Note the difference

As prescribed by the NSCP 208 5 6 Soft Soil Zone 4 as per the NSCP 208.5.6 NSCP 208 5 2 2 Zone 4 as per NSCP 2001 Figure 208-1 NSCP 208.5.2.2 RC Frames S i l M Click ok once everything is f h d Special Moment Resisting Frame NSCP Table 208-11 finished

(146)

Sap2000

Bonus: +Eccen or –Eccen?

• How do we know if we will use + or – eccen? Depends. Let us take a look at the two figures

Y

below

X

CG A id l T i CG w/o Accidental Torsion CR

CG w Accidental Torsion +eccen Y

CG w/o Accidental Torsion CR

CG w Accidental Torsion -eccen Y

(147)

SAP2000

Bonus: +Eccen or –Eccen?

• Whatever option gives the larger overall eccentricity is the way to go.

H thi i f b ildi t b ildi

• However, this varies from building to building.

• It might be worthwhile to do a template model containing the following EQ cases

containing the following EQ cases

▫ Eqx+Ecy ▫ Eqx-Ecy E E ▫ Eqy+Ecx ▫ Eqy-Ecx E E ▫ -Eqx+Ecy ▫ -Eqx-Ecy

• By Using this you got everything covered! (But

▫ -Eqy+Ecx ▫ -Eqy-Ecx

• By Using this, you got everything covered! (But don’t do this yet for our example)

(148)

SAP2000

Earthquake Loads - Automated

• Mass source

▫ The last thing we will define for the EQ loads are the mass source.

▫ To explore the options in ETABS let us go to Define Menu > Mass Source

(149)

SAP2000

Earthquake Loads - Automated

• Mass source

▫ Let us explore each option in the Mass source window _{Self and Specified Mass}

Only the selfweight of existing frame and area members will be i l d d

included

From Loads

Mass of the structure will come

f f d l d l

from specified loads. For example, you can include 100% of D + 25% of L

A combination of the first two options

(150)

SAP2000

Earthquake Loads - Automated

i i d i i ll d d l d i

• Reviewing some code provisions, all dead load in the structure should be included in the seismic weight

weight.

• Also, in some occupancy types (like warehouses), it is recommended to include 25% of the live load it is recommended to include 25% of the live load in the seismic weight

CHB Included

25% of Live load

Topping Included Beams and slabs

already in self weight

(151)

ETABS

Earthquake Loads - Automated

Mass so rce

• Mass source

▫ Let us explore the pros and cons of each option

Self and Specified Massp

Cons: Doesn’t take into account

applied loads like topping and walls. Live load can’t be taken into account

From Loads

Cons: If selfweight multiplier = 0 for the Dead load case, selfweight of the structure won’t be taken into account

won t be taken into account

Pros: You can specify which loads to include and what percentage is included. Cons: You can still specify the inclusion of Cons: You can still specify the inclusion of the Dead case but this would result in the self weight of the members doubling. Not good!

(152)

SAP2000

Earthquake Loads - Automated

• Mass source

▫ The best option is to use “From Loads”! Click ok after entering the options below.

From Loads

Use Dead Multiplier = 1 for our example

Optional: If Live load needs to be included, put a factor of 0.25 for Live load case

Standard Add, Modify, Delete

buttons. Use this to add, modify or delete load cases

(153)

SAP2000

Earthquake Loads - Automated

• Have we done everything for EQ loads?

▫ The Rigid Diaphragms ▫ The EQ constants

▫ The Mass Source

N Fi i h d f th EQ l d !

(154)

SAP2000

Final Things Before Analysis

• Let us do these first before analysis

▫ Add CHB and parapet wall loads on the perimeter ▫ Add point loads for the roof dead and live loads ▫ Complete the load cases and combinations

(155)

SAP2000

Final Things Before Analysis

• Wall outlines are shown below for 2nd _{to 4}th _floor

(Story 1 to 3). Put 5 kN/m for our case (this would vary depending on the thickness and fill of the

(156)

SAP2000

Final Things Before Analysis

• Let us go to the plan view of storey 1 first

• To put uniform loads.

▫ Select the beams on the perimeter

(157)

SAP2000

Final Things Before Analysis

• In the frame distributed loads window input the following

Note the fields highlighted

(158)

SAP2000

Final Things Before Analysis

• In the plan view it’s difficult to see the uniform loads

• In the plan view it s difficult to see the uniform loads.

• Go to 3d view to have a clearer picture

(159)

SAP2000

Final Things Before Analysis

• Apply the 5 kN/m uniform dead load to the storey 2 and 3

(160)

SAP2000

Final Things Before Analysis

• Put half the value (2.5 kN/m) on the perimeter beams on the roof level for the parapet wall

(161)

SAP2000

Final Things Before Analysis

(162)

SAP2000

Final Things Before Analysis

(163)

SAP2000

Final Things Before Analysis

• Add point loads for the roof dead and live loads

▫ Add the following joint loads as indicated. These values would vary from structure to structure!

D:65 kN L: 22 kN _{D:65 kN} D:33 kN L: 11 kN D:33 kN L kN

These values for sample

D:65 kN L: 22 kN D:65 kN L: 22 kN L: 11 kN purposes only! D:65 kN L: 22 kN D:65 kN L: 22 kN D:65 kN L: 22 kN D:33 kN L: 11 kN D:33 kN L: 11 kN

(164)

SAP2000

Final Things Before Analysis

• Let’s go to the plan view of the roof (storey 4)

• Let s go to the plan view of the roof (storey 4)

• To add joint loads

▫ Select the joint you want to apply force ▫ Go to Assign > Joint Loads > Forces

▫ Choose the appropriate load case and input the loads ▫ Use global axes as shown aboveUse global axes as shown above

(165)

SAP2000

Final Things Before Analysis

• Go to 3d view to check out the load

(166)

SAP2000

Final Things Before Analysis

• Complete the joint loads for dead and live load

(167)

SAP2000

Final Things Before Analysis

• And Last, Complete the load cases and

combinations (no serviceability combinations for now!) ▫ 1.4D+1.7L 1 3D 1 1L 1 1EQ 0 33EQ ▫ 1.3D+1.1L+1.1EQx+0.33EQy ▫ 1.3D+1.1L+1.1EQy+0.33EQx ▫ 1 3D+1 1L-1 1EQx+0 33EQy

These combinations take into account

recommendations of

1.3D+1.1L 1.1EQx+0.33EQy ▫ 1.3D+1.1L-1.1EQy+0.33EQx ▫ Envelope of all combinations

NSCP 2001 208.8.1 for seismic attack in both directions

(168)

SAP2000

Final Things Before Analysis

• Load case list with shown sample

(169)

SAP2000

Final Things Before Analysis

• Now let us analyze the structure!

(170)

SAP2000

Final Things Before Analysis

• Analysis Finished!

(171)

SAP2000

Post-Analysis Check

• As discussed in part 1, the best way to know if we don’t have errors or disconnections in the

structure is through the deflection diagram.

• You can also click the animate button at the

b tt t t th ff t th d fl ti !

bottom to exaggerate the effect the deflection! (Warning: there is background music for our

dancing structure Please turn down your volume dancing structure. Please turn down your volume if you don’t want to get startled.)

(172)

SAP2000

Post-Analysis Check

• Floor by floor check of deflections

(173)

SAP2000

Post-Analysis Check

(174)

SAP2000

Post-Analysis Check

(175)

SAP2000

Post-Analysis Check

(176)

SAP2000

Post-Analysis Check

• To remove the deflected shape Go to Display Menu > Show Undeformed Shape

(177)

SAP2000

Output Processing: Table Output and Excel

• An alternative way of showing output is through

tables tables.

• Table output useful if we will use values for design in a spreadsheet program.

design in a spreadsheet program.

• But first, we need to have a legend: An output

(178)

SAP2000

Extra: Showing Line Labels Etc.

• To show the labels of the beams, let us go to plan view of the story 1 first

(179)

SAP2000

Extra: Showing Line Labels Etc.

l i i l

• Now let us go to View Menu > Set Display Options

Check Labels under Frame and click ok Notice

• Check Labels under Frame and click ok. Notice that labels are now shown on each beam and column

column

(180)

SAP2000

Extra: Showing Line Labels Etc.

h i f h hi f

• To have a printout of the graphic for your own reference (or for calculation submission) just go to File Menu > Print Graphics

to File Menu > Print Graphics

Sample output Sample output in SAP2000

(181)

SAP2000

Extra: Showing Line Labels Etc.

i ill h f ll i

• In your printout you will see the following information in the bottom

(182)

SAP2000

Extra: Showing Line Labels Etc.

l i h “l d” f i

• Now let us print out the “legend” for stories 2 to 4 (3rd _{Floor to Roof Level)}

(183)

SAP2000

Extra: Showing Line Labels Etc.

b k i l i d h k h

• Go back to Set Display options and uncheck the Fame labels option to remove the line labels.

(184)

SAP2000

Output: Table Output and Excel

h h l d l i h bl

• Now we have the legend, let us print the table output!

Go to displa Menu > Sho Tables

(185)

SAP2000

Output: Table Output and Excel

h i i h bl

• There are so many options in the table output. But let us just a few of the options. Further

exploration is up to you the user exploration is up to you the user.

• Basically we can summarize the output into the following:

following:

▫ Choose the load combinations ▫ Choose what to outputp

(186)

SAP2000

Output: Table Output and Excel

l

• For our example:

▫ Choose the load combinations (5 combinations) Choose what to output (Frame forces)

(187)

SAP2000

Output: Table Output and Excel

h i d li k “ l d ”

• In the window, click “Select Load Cases”

• A window will appear showing the different combinations

(188)

SAP2000

Output: Table Output and Excel

l h bi i

• To select the combinations you can:

▫ Click them one by one by holding ctrl key Or hold the shift key to select multiple cases ▫ Or hold the shift key to select multiple cases • Let us select the intended cases and click ok

when done when done.

(189)

SAP2000

Output: Table Output and Excel

N l l h h F f

• Now let us select to show the Frame forces

• Expand the “Element Output” option by clicking +.

Expand “Frame Output” again then click the box on the Expand Frame Output again then click the box on the left of “Table Element Forces - Frame”

An x indicates An x indicates selection Click ok when Click ok when done

(190)

SAP2000

Output: Table Output and Excel

i d ill h h h f

• A new window will appear that shows the frame

forces

This is a long collection of data SAP has a

• This is a long collection of data. SAP has a limited capability of processing these data.

(191)

SAP2000

Output: Table Output and Excel

h bl l h h h

• We can export the table to excel through the following

• Once chosen excel will open with the said data (Of

• Once chosen excel will open with the said data. (Of course you must have Excel in your computer!

Save the excel data to the desired

(192)

SAP2000

Output: Table Output and Excel

d i i l d hi

• Now your data is in excel! You can do anything with it through excel’s powerful functions. But that is another seminar for another day!

(193)

SAP2000

Output: Table Output and Excel

li k d if b k d l

(194)

SAP2000

Output: Table Output and Excel

h i h i h

• There is more to the output options than meets the eye!

Up to ou to e plore further!