To compare results with small displacement formulation nonlinear analysis:
-
Right-click the Simulation study tab and select Copy Study.
-
In the Copy Study PropertyManager, for Study
name type Small Displacement.
-
In the Small Displacement study tab,
right-click the top study name icon, and click
Properties. In the Nonlinear -
Static dialog box, clear Use large
displacement formulation.
-
Run the study.
-
View the results. The table below summarizes the results.
| Quantity
|
Large Displacement Formulation
|
Small Displacement Formulation
|
|---|
| Maximum Resultant Displacement
(20,000 N/m2 pressure)
|
1.633 cm
(Step 10)
|
0.406 cm
|
| Max von Mises Stress at top face
(20,000 N/m2 pressure)
|
1.142E+08 N/m2 (Step 10)
|
2.207E+08 N/m2
|
| Maximum Resultant Displacement
(2,000 N/m2 pressure)
|
0.3773 cm
(Step 1)
|
0.406 cm |
| Max von Mises Stress at top face
(2,000 N/m2 pressure)
|
2.030E+07 N/m2 (Step 1)
|
2.207E+07 N/m2
|
The results from the large and small displacement formulation are very close for the first solution step (Step 1) when only 1/10 of the load is applied and the displacements are still small.
The results from the two nonlinear studies deviate significantly at the last step
(Step 10) when the
full
load is applied. The small displacement assumption is not valid anymore, and the
large displacement formulation gives the correct results.
Congratulations! You have completed this lesson.