Etabs Flowchart v.9

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Etabs Flowchart: Etabs Flowchart: A. Structural Analysis

A. Structural Analysis

1.0

1.0 _{Set the unit: click at the lower right, use KN-m}_{Set the unit: click at the lower right, use KN-m}

2.0Model Initialization:

2.0Model Initialization: NO NO (to use the (to use the built-in Ebuilt-in Etabs Default)tabs Default) 1.1Grid Dimension

1.1Grid Dimension (click (click Custom GrCustom Grid Spacing id Spacing to edit)to edit) 1.2Story Dimension

1.2Story Dimension (click (click Custom SCustom Story Data ttory Data to edit)o edit) 3.0Define

3.0Define

3.1Material Property Name 3.1Material Property Name

a.

a. _{Click Conc – Modify/Show Material}_{Click Conc – Modify/Show Material}

P

Paarrttiiccuullaarr RReemmaarrkkss EExxaammpplle e VVaalluuee U

Unniittss UUsseedd KKNN--mm KKNN--mm T

Tyyppe e oof f MMaatteerriiaall IIssoottrrooppiic c ((uussuuaalllly y uusseedd for RC and steel)

for RC and steel)

Isotropic Isotropic C

Coonnccrreette e ccoommpp. . sttrres ennggtthh, , ff’’cc 2277557799 Bending Reinf. Yield Stress,

Bending Reinf. Yield Stress, Fy

Fy

413685 413685 S

Shheeaar r RReeiinnff. . YYiieelld d SttrreS essss, , FFyy 227755773300 M

Maasss s ppeer r UUnniit t VVoolluummee 22..44000077 W

Weeiigghht t ppeer r UUnniit t VVoolluummee 2233..55661166 M

Moodduulluus s oof f EEllaassttiicciittyy = = 4477330 0 x x ssqqrrt t ((ff’’cc inMPa) x 1000 inMPa) x 1000 24821128 24821128 P Pooiissssoonn’’ss RRaattiioo 00..22 C

Cooeeffff. . oof f TThheerrmmaal l EExxppaannssiioonn 99..990000EE--00..66 *Conversion from concrete cube (fcu) to

*Conversion from concrete cube (fcu) to cylinder strength (f’c) usingcylinder strength (f’c) using L’Hermite formula:

L’Hermite formula: f’c = 0

f’c = 0.76 + .76 + 0.2 log 0.2 log (fcu / (fcu / 2840) 2840) where: fcwhere: fcu in u in psipsi ex

exaammplple:e: fcfcu u = = 4040MPMPa a = = 58580101..5151pspsii therefore:

therefore: f’c f’c = = 0.822 0.822 * * fcu fcu = = 32.88MPa32.88MPa 3.2Frame Section

3.2Frame Section

a.

a. _{Click Add Rectangular (arrow down the second dialog box at}_{Click Add Rectangular (arrow down the second dialog box at the}_the

right ), then click Modify/Show Material right ), then click Modify/Show Material

b.

b. _{Modify Concrete Reinforcement (There are two tabs in the}_{Modify Concrete Reinforcement (There are two tabs in the}

reinforcem

reinforcement data dialog box. ent data dialog box. They are labeled column and beam.They are labeled column and beam. Pick the tab that

Pick the tab that corresponcorresponds to the ds to the frame section you areframe section you are defining.)

defining.)



 For beams: input As (area of For beams: input As (area of steel reinf.) at reinforcementsteel reinf.) at reinforcement

overrides for ductile beams for

overrides for ductile beams for investigationinvestigation. Otherwise,. Otherwise, leave it at default values, 0

leave it at default values, 0 c.

c. Set ProSet Property Moperty Modifidifier: Inpuer: Input modit modificafication fation factor foctor for momer moment of nt of inertia (for crack section, usually 0.7 for columns & 0.5

inertia (for crack section, usually 0.7 for columns & 0.5 for beams)for beams) 3.3Wall/Slab/Deck Section

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a. _{Click Add Deck or Wall or Slab (arrow down the dialog box at the}

right ), then click Modify/Show Material

b. Type thickness for membrane and bending (same thickness) c. Choose the type to be used:

• Click Shell Type Behavior (Out-plane stiffness is provided for

the section) – usually used for cantilever slabs and walls

• Click Membrane Type Behavior (Only in-plane membrane

stiffness is provided for the section) – usually used for slab

• Click Plate Type Behavior (Combination of Out-plane and

in-plane stiffness is provided for the section)

4.0 _{For Dynamic Analysis: Define Response Spectrum Function – define UBC97 &}

add UBC97 Spectrum

5.0Define Static Load Case Name

Load Type Self Wt.

Multiplier

Auto Lat. Load

Dead Dead 1

-Live Live 0

-EQX Quake 0 UBC97

EQY Quake 0 UBC97

5.1_{Choose EQX then click Modify Lateral Load}

5.2_{Direction & Eccentricity} ₌ _{X-dir. + Eccen Y}

Particular UBC NSCP Referen ce Constant Referenc e Constant Eccentricity Ratio 0.05 0.05

Time Period 1630.2.2 Steel = 0.035 RC = 0.030 Other = 0.020 208.5.2.2 Steel = 0.0853 RC = 0.0731 Other = 0.0488

Story Range Top Most

level to Ground Floor only Top Most level to Ground Floor only Overstrength Factor, R 16-N SMRF for Steel & RC = 8.5 208-11 SMRF for Steel & RC = 8.5 Seismic Coefficient:

Per Code Per Code

Soil Profile 16-J SC 208-2 SC

Seismic Zone Factor

16-I 0.4 208-3 0.4

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Factor Distance to Source (Km) 10 10 Importance Factor, I 16-K 1 208-1 1

5.3_{Choose EQY then click Modify Lateral Load}

5.4_{Direction & Eccentricity} ₌ _{Y-dir. + Eccen X}

5.5Copy constant used for EQX

6.0For Dynamic Analysis: Define Response Spectrum Case Data 6.1add new spectrum

Mark x-direction y-direction

Spectrum Case Name Specx Specy

Damping 0.05 0.05

Modal Combination CQC CQC

Directional Combination SRSS SRSS

Input Response Spectra U1 = 1 (scale factor) U2 = 1 (scale factor)

Excitation Angle 0 0

Override Eccentricity 0 0

7.0Load Combination (ultimate design due to earthquake based on NSCP) 7.1Based on NSCP: Comb1: 1.4DL Comb2: 1.4DL + 1.7LL Comb3: 1.3DL + 1.1LL + 1.1EQX Comb4: 1.3DL + 1.1LL - 1.1EQX Comb5: 1.3DL + 1.1LL + 1.1EQY Comb6: 1.3DL + 1.1LL - 1.1EQY Comb7: 1.42DL + 1.0LL + 1.0EQX Comb8: 1.42DL + 1.0LL - 1.0EQX Comb9: 1.42DL + 1.0LL + 1.0EQY Comb10: 1.42DL + 1.0LL - 1.0EQY 7.2Based on UBC’97: cas e DL LL LLr E WL H T F 1 1.40 1.70 1.70 - - - - -2 1.40 1.70 1.70 - - 1.70 - 1.40 3 1.05 1.275 1.275 - 1.30 - - 1.40 4 1.05 1.275 1.275 - - - 1.05 1.05 5 1.40 - - - 1.40 -6 1.32 0.55 - 1.10 - - - 1.54 7 1.20 0.5 0.5 - 1.30 - - -Where: DL = deadload LL = liveload LLr = roof liveload E = earthquake WL = windload

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H = Earth pressure

T = effects due to creep, shrinkage, thermal gradients and differential settlement F = fluid loads

Where dead and live load are beneficial, the following shall apply: cas e DL LL LLr E WL H T F 2R 0.90 - - - - 1.70 - 1.40 3R 0.90 - - - 1.30 - - -6R 0.90 - - 1.10 - - -

-8.0Special Seismic Load Effect (check reliability /redundancy factor)

8.1_{Rho Factor – reliability /redundancy factor – choose program calculated}

8.2Omega factor – 2.8 9.0Define Mass Source

9.1From Loads – define mass multiplier (DL &SDL = 1) 9.2Uncheck – include lateral mass only

9.3Checked – Lump lateral mass at story levels 10.0 Draw & Assigned

10.1 _{Column – (elev. view - easier to draw)}

10.2 Column – check column orientation in plan view

 If adjustment is needed – select columns at elev. view, click

Assign, Frame/Line, Local Axes and type the desire angle

10.3 _{Wall– (elev. view - easier to draw)}

10.4_{Joint/Point – Restraint (support) – fixed (click joint at base level for}

footing Support – columns & walls)

10.5 _{Shell/Area – Pier Label (for design of walls)} 10.6 _{Beams & Girders (plan view – easier to draw)}

10.7 _{Frame line – Frame Releases/Partial Fixity – check Moment 2-2 & 3-3}

for pin connection (intermediate beams)

10.8 _{Slab (plan view – easier to draw) - please ensure proper meshing, as}

much as possible use only 3 to 4 point nodes in modelling slabs element.

10.9 _{Assigned Diaphragm – Select all elements (plan view per floor) –}

Assign\Shell/Area\Rigid Diaphragm, select D1 11.0 Assigned Loads

11.1 Select area – assign shell/area loads - uniform

11.2 Select line – assign frame/line loads – point or uniform loads 11.3 Select point – assign joint/point load – joint forces

12.0 Analyze – set analysis option

12.1 Building Active Degrees of Freedom – checked full 3D 12.2 Check Dynamic Analysis if applicable

12.2.1Dynamic Parameters – used Eigenvectors

12.2.2No.of modes - check if structure is 90% participated for static

12.3 P-Delta effect - check if applicable

13.0 _{Analyze – check model – checked all boxes for checking}

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15.0 _{Verify Analysis - File – Last Analysis Run Log – check for warnings messages} 16.0 _{Check graph of storyshear, Display – Show Story Response Plots – choose}

Story Shears. Curve should be gradual curve 17.0 Check period, T:

File – Print Tables – Summary Reports – scroll down – Modal Period and Frequencies, T for mode 1 should be </+ 5secs.

18.0 Check Mode Shape:

18.1 _{File – Print Tables – Summary Reports – scroll down – Modal}

Participating Mass Ratios – Rotation for Mode 1 and 2 should be minimal.

18.2 _{Check movement at plan view, at the upper most level: Display –}

Show Mode Shape – rotation should not occur on Mode 1 and 2 19.0 Check modal participation, static should be at least 90% participated

File – Print Table –Summary Report – scroll down – from Modal Load Participation Ratios

20.0 Modify scale factor for dynamic analysis:

20.1 _{File – Print Table –Summary Report – scroll down - from Total}

Reactive Forces (Recovered Loads) @ Origin, compare the following:

• Quake X versus SpecX (FX)

• Quake Y versus SpecY (FY) • Quake X versus SpecXY (FX) • Quake Y versus SpecXY (FY)

20.2 Compute scale factor

• Scale factor-1 = Quake X / Spec X • Scale factor-2 = Quake Y / Spec Y

20.3 Adjust scale factor

A . Define – Response Spectrum Case – SpecX - Modify /show Spectrum – change scale factor as computed above

B. Define – Response Spectrum Case – SpecY - Modify /show Spectrum – change scale factor as computed above

Note: Upon adjustment of scale factor, Static (Quake) should be almost equal with Dynamic (Spec)

21.0 Check story drift

File – Print Tables – Summary Reports – scroll down – Story Drift B. Concrete Frame Design

1.0 _{Design – Concrete Frame Design – Select Design Combo – choose the desire}

load combination to be used for design, used the add or remove icon to choose.

2.0 _{Design – Concrete Frame Design – Start Design/Check of Structure} 3.0 _{Design – Concrete Frame Design – Display Design Info}

• Longitudinal Reinforcing – defined as As in mm2:

# rebars = As / As1where As1 = area of one reinf. bar in mm2

• Shear Reinforcing – defined as As/meter in mm2/m:

Spacing, s = As1/As where As1 = area of one reinf. bar in mm2 • Torsion Reinforcing

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