Example

forces due to singularities, etc. the calculation is allowed to continue without an error message, but supplies messages after the calculation has finished.

The program always converges to a solution. The program does not warn the user when the loading is bigger than the capacity of the cross section. It is assumed that the user did in a first step a proper design of the reinforcement in the concrete members.

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The user can define the creep coefficient, or let the program determine the creep coefficient using the EC appendix B1. Please find the setting in the concrete setup at the SLS settings

An error message concerning about not sufficient mesh may appear during the CDD calculation. If so, mesh should be improved and then linear and CDD calculations should be started again.

In the solver setup, the user can change the amount of reinforcement for the CDD. This option is intended to correct the theoretical reinforcement by this coefficient. Default value is 1. Let’s remark that the program doesn’t display a warning when you use this option when practical reinforcement has been defined in the member.

3.8.3 Example

To demonstrate this functionality we can continue with the example used in previous chapters of ULS and ULS+SLS designs.

As a first step we need to create concrete combinations necessary for calculation of code dependent deflections. We will set Load case 1, where only self weight is defined, for determining permanent code dependent deflections and Load case 2, where all load are defined, for determining the code dependent deflection caused by creep.

We will also define reinforcement for second direction and also for upper surface. User reinforcement for both surfaces and both directions will satisfy the ULS design only. For information about the input reinforcement see table below:

User reinforcement As1- User reinforcement As2-

User reinforcement As1+ User reinforcement As2+

After the reinforcement design of the user reinforcement for ULS state, it is time to define the reinforcement determining the Code dependent deflections. It can be done in Setup dialog in Menu >

Setup > Concrete solver. Picture of this dialog is shown in the previous chapter. We will set this parameter to User reinforcement possibility. Then we must run the design once again to regain the amounts of reinforcement.

Now if we start the FE analysis dialog, possibility Concrete – Code Dependent Deflections (CDD) is activated and may be chosen. After selection of this option we can proceed to calculation itself by pressing Ok button.

After confirmation of the FE analysis dialog a warning error may appear. This will warn the user about non-consistent location parameter of 2D design.

If the user accepts the dialog above, the calculation itself is started and process of determining the deflections should be finished with informational End of analysis dialog. Here maximal values of translation and rotation is displayed.

Now if we go back to the concrete service, two new items Stiffness presentation and Deformations, may be found here. They are both under Member check item. See picture below.

3.8.3.1 Stiffness presentation

In this service the user may choose to display two types of results. Location is set permanently to “In centres” possibility. The parameter type of values may be set to:

o Required area

As1- longitudinal reinforcement for lower surface and direction 1 As2- longitudinal reinforcement for lower surface and direction 2 As1+ longitudinal reinforcement for upper surface and direction 1 As2+ longitudinal reinforcement for upper surface and direction 2 As1 overall longitudinal reinforcement for both surfaces and direction 1 As2 overall longitudinal reinforcement for both surfaces and direction 2

o Stiffness

EI1,s bending stiffness from short term load in direction 1 EA1,s normal stiffness from short term load in direction 1 EI2,s bending stiffness from short term load in direction 2 EA2,s normal stiffness from short term load in direction 2 EI1,l bending stiffness from long term load in direction 1 EA1,l normal stiffness from long t term load in direction 1 EI2,l bending stiffness from long term load in direction 2 EA2,l normal stiffness from long term load in direction 2

There may be also displayed values for required areas and stiffness for the third direction, but it must be defined in advance.

Here is an example of the bending stiffness from short-term load in direction 1.

3.8.3.2 Deformations

In this service, the user may display the code dependent deflection calculated from the settings already defined in whole process. The user may choose to set parameter Deformation to three possible options:

o linear will display linear deformation o nonlinear will display nonlinear deformations

o nonlinear with creep will display nonlinear deformations including creep Parameter type of values may be set to another three options:

o Uz deformation in Z-axis direction o Fix rotation around X-axis direction o Fiy rotation around X-axis direction

In the table below, we can compare the deformation in the Z-axis direction with different Deformation parameter.

Linear Nonlinear

Nonlinear with creep

As it is clear from the table, the largest values of Code Dependent Deflections are for Nonlinear with creep deformations.

References

[1] EN 1992-1-1: 2004 Eurocode 2 : design of concrete structures – Part 1: General rules and rules for building

[2] ENV 1992-1-1: 1991 Eurocode 2 : design of concrete structures – Part 1: General rules and rules for building

[3] Hobst, Ed.: ESA-PRIMA WIN & SCIA.ESA PT REINFORCED CONCRETEDESIGN OF 2D STRUCTURES, Theoretical background

[4] Internal Scia Engineer manuals