Recalc > Extended Settings

Special Settings

Setting	Description
Use Shear Lag Defs. for Stiffness reduct.	Cross-sectional areas denoted as shear lag areas are ignored in the section property calculation (bending moments of inertia). If the option is tagged, the structural analysis is performed with these reduced values. If not tagged, the reduced values are only used for stress calculation. Axial loads are always acting on the total section and self weight is also always related to the full cross section. For details see Shear lag definition .
Join Primary Forces to Composite	Primary forces of partial elements of composite elements are automatically joined and assigned to the respective composite elements. Otherwise, primary forces of partial elements are only assigned to the partial elements.
Include Primary TempVar effects	Primary stress of non-linear temperature distribution load cases will be considered in the calculation of stress results. This option requires the definition of stress points with the respective flag specifying that primary stresses due to TempVar shall be defined in the created load set. Attention: The option that primary stresses in arbitrary user-defined stress points can be stored and later considered has been implemented in July 2011. Previously, considering primary stresses was only possible by creating fictitious primary forces defining the primary stress of the top and bottom points. Stresses in other stress points were incorrect and also the internal forces, which contained a fictitious primary part. This obsolete procedure can still be used by selecting the respective Primary State option in the action TempVar.
Ignore shear deformation	Shear deformations due to shear forces are neglected in the analysis.
Store leading envelope results for finite elements	This option provide access to the Envelope-FE results. Note: Envelope-FE results for shell elements will be disabled with blank output if user don't select this option.
Create result lists for area loading	This option generates an auxiliary lst file which contains the shell element loads when the load case with shell loads is analyzed.

Prestressing

Setting	Description
Update CS Values : ( + ) Tendon Areas	Tendon steel area is included in updated cross-section property calculation. The update is performed in the Grout action.
Update CS Values : ( - ) Duct Areas	Duct area is excluded in updated cross-section property calculation. The update is performed in the Structure check prior to the Schedule calculations.
Update CS Values : ( + ) Grouted Areas	The grout material between duct and tendon is included in updated cross-section property calculation with material parameters of beam element (regular concrete quality). The update is performed in the Grout action. Note: All cross-section updates are only used for post-processing actions (stress calculation, design code checks). Stiffness calculation for the static analysis is always performed with the original gross cross-section of the beam elements, and internal forces are always related to the original element axis (center of gravity).
Include El. Comp. losses for ungrouted	Losses in tendon forces due to elastic compression of the concrete for ungrouted tendons are treated in the same way than for grouted tendons. No losses in ungrouted tendons will be calculated if the option is not selected.
Ext. tendon (Prim.+ Sec.throughout)	Selection treats external tendons in the same way than internal tendons with results split into primary and secondary components (expected engineering solution). (Non-selection uses a more accurate model with real cable elements with results as total component).
Store slave tend. geometry as 3D points	Slave tendon geometry points will be stored as (absolute) 3D coordinates. If the option is not selected, the tendon geometry is stored relative to the element points.

Creep and Shrinkage

Definition of parameters for governing the creep and shrinkage calculation . The accuracy of the calculation can be increased on the one hand by subdividing the creep interval into smaller step, and on the other hand by defining an appropriate ageing factor.

Setting

Description

Storage-Alt. for C+S Effects (Comp.)

Alternative storage of creep components in composite structures. If the option is selected, secondary and primary components of the creep results are exactly calculated and stored accordingly. In the default case (option not selected), creep due to the stressing state at the begin of the creep interval is separated into a primary and secondary part, but creep due to the stressing state difference arising in the creep interval will be totally stored as secondary force.

Print creep and shrinkage factors

The creep and shrinkage factors used for the individual loading components are printed in the result listings of the creep loading cases (eg. file creep#1.lst).

C+S Calculation Internal Formula

Respective internal program functions are used in the creep and shrinkage calculation instead of the variables assigned in Properties > Variables.

Use Full CS for Creep calculation

Should always be checked! Previous versions of the program inconsistently used only the concrete section without duct areas although stiffness is always related to the gross cross-section. The un-checking possibility has been kept for compatibility reasons with older versions.

Time stepping

Setting

Description

Linear:

A linear subdivision is applied in case of subdivision of the total creep period Delta-T into N time steps, i.e. the individual steps will have the length Delta-T / N.

Logarithmic:

A logarithmic subdivision is applied in case of subdivion of the total creep period TB to TE into N time steps (Dlog = [Log(TE) - Log(TB)] / N). I.e. the points in time (Ti) at the ends of the time steps will be Ti = 10^(Log(TB)+i*Dlog).

Note: The logarithmic interpolation is only valid for the subdivision of the creep interval into N time steps, but not for the subdivision of the individual time steps into 2 parts with the aging factor w2.

Aging factor w2:

The aging factor serves for taking into account the fact, that stresses due to creep and shrinkage arise continuously during the creep interval. They are therefore only partly inducing further creep (or reducing the creep rate).

Default: 0.5

Attention: Note that the aging factor is related to time and not to the creep coefficient Phi as the value Theta often used in scientific textbooks. Mathematically, the program works with the model, that the arising stress changes are not effective for creep till the time TB+DT*w2, and fully active afterwards till TE.

In classical creep laws (Phi=Phi(T)) this means, that we have with w2=0 a fully implicit (backward difference) scheme, and with w2=1 an explicit (forward difference) scheme. I.e. for guaranteed stability w2 should be smaller than 0.5, in no case greater.

In modern creep laws, where loading time governs the behavior in addition to the time itself (Phi=Phi(T,T0)) the assumption that TA+DT*w2 is the loading time of creep stresses makes also approaches with w2 > 0.5 reasonable. However, the default setting of w2 = 0.5 is an acceptable compromise for all creep laws and should in general not be changed.

In cases where doubts on the accuracy of the results arise, the user should output and check the Delta-Phi values of the current stress changes. W2 shall be reduced if these values are too small.

Start Date

The date is used in the program construction schedule as reference value