Step/Thermal Load Tab

Setting Item

Notes

Step Setting

Stress Analysis

Sets either single step or multiple steps.

For the analysis of the load or reached temperature over time, select multiple steps.

If [Thermal load] on the [Stress analysis tab] is selected, the following display will show up.

[Thermal load analysis] corresponds to the single step and [Multi-step thermal load analysis] to the multiple steps.

If [Buckling analysis] is selected in the stress analysis, single step is only selectable.

Piezoelectric Analysis

If, on the [Piezoelectric analysis tab], [Thermal load] is deselected, [Single step] will be automatically selected.

If, on the [Piezoelectric analysis tab], [Thermal load] is selected, [Thermal load analysis] will be automatically selected.

Time Setting

Stress Analysis

Allows you to execute analysis with time setting or without time setting.

To perform creep analysis or viscoelastic analysis, select [Set up] for Time Setting.

Time setting takes effect in the creep analysis and the viscoelastic analysis.
Except for these analyses, time setting will not affect analysis results.

* Creep analysis and viscoelastic analysis are available in an optional package.

If [Buckling analysis] is selected for Analysis Type, [No setting] is only selectable.

Piezoelectric Analysis

[No setting] is always selected.

Reference temperature (non-stress temperature)

Stress Analysis

Sets the temperature of a model before the thermal deformation. It is assumed that the stress is not generated at this temperature.

Allowed to enter if [Thermal load] is selected on the [Stress analysis tab].

If [Use distribution data] is selected,
the reference temperature is set with distribution.

Click the [Distribution Data] button to open the dialog box.
See [How to Set Distributed Boundary Condition and Body Attribute] for the detail.

Distributed reached temperature can be set only when [Thermal load analysis] is selected for Step Setting.

Piezoelectric Analysis

Sets the temperature of a model before the thermal deformation. It is assumed that the stress is not generated at this temperature.

Allowed to enter if [Thermal load] is selected on the [Piezoelectric analysis tab].

[Use distribution data] is not selectable as it i s not supported.

Step/Reached Temperature Setting

Dialog Box

Stress Analysis

*) If [Single step] is selected for the Step Setting and the linear analysis is set, the dialog box will not appear as the setting is not required.

*) Items not required for the setting will not be shown.

Piezoelectric Analysis

*) in the linear analysis, if the thermal load is not selected on the [Piezoelectric analysis tab], the dialog box will not show up as the setting is not required.

Step

Stress Analysis

If [Multiple steps]([Multi-step thermal load analysis]) is selected, desired number of steps can be set.

Step numbers in Birth/Death Setting on the Analysis Domain tab and [ON/OFF Setting] on the Mechanical tab correspond to the steps on this table.

If [Multiple steps](or [Multi-step thermal load analysis]) is selected for Step Setting, and [No setting] is selected for Time Setting,
select [Time Dependency] on the Mechanical tab to set steps and weight.

Piezoelectric Analysis

1 is only allowed to enter.

Time

Stress Analysis

Available if [Set up] is selected for Time Setting.

Enter the real number 0 or more.

The start time of each step is the end time of the previous step. The start time of step 1 is zero. The end time must be a positive real number.

If [Multiple steps](or [Multi-step thermal load analysis]) is selected for Step Setting, and [Set up] is selected for Time Setting,
select [Time Dependency] on the Mechanical tab to set time and weight.

Piezoelectric Analysis

Not allowed to enter.

Substeps

Stress Analysis

Available if [Single step] (or [Thermal load analysis]) is selected for Step Setting and nonlinear analysis (large deformation, contact, nonlinear material such as elastic) is set.
Also available if [Multiple steps] ([Multi-step thermal load analysis]) is set for Step Setting.

Sets the number of substeps for each step.

This will affect the accuracy and convergence of the nonlinear analysis.

If you want to output the results of substeps,

select [Save the results of substeps].

Piezoelectric Analysis

Allowed to set in the nonlinear analysis (large deformation and contact).

Reached Temperature

Stress Analysis

Sets the temperature at the end time of each step.

Allowed to enter if [Thermal load] is selected on the [Stress analysis tab].

Temperature changes linearly over the substeps within a step.

If [Thermal load analysis] is selected for Step Setting, and Use distribution data is selected in the Options for the Reached Temperature,
the reference temperature is set with the user-defined distribution.

If [Multi-step thermal load analysis] is selected for the Step Setting, you can view the time-temperature graph by pressing [Temperature Graph] button.
(Reference temperature set on the Thermal Load tab is referred to at time/step 0)

Piezoelectric Analysis

Allowed to enter if [Thermal load] is selected on the [Piezoelectric analysis tab].

Table

Stress Analysis

Opens Time/Step Table window.

The following are displayed on the table.

[Single step] (or [Thermal load analysis])

You can compare the load set on the Mechanical tab and the actual load reflected in in each substep.

[Multiple steps] (or [Multi-step thermal load analysis])

1) Birth/Death of each body attribute set on Analysis Domain tab.

2) Material Change of each body attribute set on Material Change tab.

3) ON/OFF of each boundary condition set on Mechanical tab.

4) Weight Function of each boundary condition set on Mechanical tab. See [Weight Function Setting].

1), 2), and 3) are editable on the table.

Piezoelectric Analysis

Not available.

Options for the Reached Temperature
(Single Step Only)

Use Distribution Data

Stress Analysis

Allowed to enter if [Thermal load] is selected on the [Stress analysis tab].

If Use distribution data is selected,
the reference temperature is set with distribution.

Click the Distribution Data button to open the dialog box.
See [How to Set Distributed Boundary Condition and Body Attribute] for the detail.

Piezoelectric Analysis

Not available.

Options for the Nonlinear Analysis
(Single Step Only)

Save the Results of Substeps

Outputs the results of substeps specified in the step/reached temperature setting.

Available for the tress analysis and the piezoelectric analysis.

Add Unloading Step

For the second step, add a step to unload the load (including thermal load) which was applied in the first step.

Available for the tress analysis and the piezoelectric analysis.

Options for the Multi-Step Analysis
(Multiple Steps Only)

Not available for the piezoelectric analysis.

Dialog Box

Save the Results of Substeps

If you want to output the results of substeps,
select [Save the results of substeps].

Apply Mechanical Load and Forced Displacement
at the Final Step

Usually, mechanical load and forced displacement are applied from the first step.
If this option is selected, the load and the forced displacement are only applied at the final step of the multiple steps.

[Electrostatic force] and [electrostriction] in the electric stress coupled analysis and [electromagnetic force] in the magnetic stress coupled analysis also applied only at the final step.

Fatigue life assessment

Sets the options for the fatigue life assessment.

* Fatigue life assessment is available in an optional package.

If [Fatigue life assessment] is selected, the fatigue life of the model is predicted. This prediction is based on Manson-Coffin law.

To assess the fatigue life, a part of the model must be made from inelastic (elasto-plastic or creep) material.

[Reference Step] sets the standard step and the final step to obtain the equivalent inelastic strain amplitude from the accumulated equivalent inelastic strain of the multi-step analysis.

[Standard step] accepts an integer 0 or greater but smaller than the maximum step number.

[Final step] accepts an integer greater than 0 up to the maximum step number.

[Output the results of standard and final steps only] reduces the size of the result file.

Coefficient of Manson-Coffin Law's sets the coefficient of Manson-Coffin law's to calculate the life

from the equivalent inelastic strain amplitude.

Manson-Coffin law

Nf = C Δεne^n

where Nf is the fatigue life (unit: cycles). Δεne is the equivalent inelastic strain amplitude (unit: %)

C is the fatigue life when the equivalent inelastic strain amplitude (Δεne) is 1%.

An integer greater than 0 is acceptable.

n is the influence parameter of Δεne.

A negative real number smaller than 0 is acceptable.

Refer to [Fatigue Life Assessment] of the Technical Notes for details.

Options for Restart/Suspend

Allows you to restart or suspend the analysis.

To restart the analysis, select Restart from the last suspended step.

(Analysis must be suspended at least once.)

Analysis will be suspended at the step set in Suspend at Step

If the specified step number is greater than the analysis step number in the Step/Reached Temperature Setting, the analysis will not be suspended

until the calculation reaches the final step.

Suspend and restart is of use for the cases below.

- Adjust the analysis conditions after evaluating the results of previous steps.

- Add new steps following the previous analysis.

Nonlinear Setting Status

Tells you if the analysis is nonlinear.

- If the analysis is not nonlinear

Substep setting is not required.

- If the analysis nonlinear

Substep setting is required.

Substeps will affect the accuracy and convergence of the analysis.

Available for the tress analysis and the piezoelectric analysis.