# Homework, Quizzes, Simulation Examples — Nonlinearity – Lesson 4

### Simulation Examples

Several simulation examples are provided here. Each of them comes with a description file, video instruction and Ansys simulation file. All of the simulations are conducted by Ansys experts. Download the student version of Ansys software here.

#### (1) O-ring seal

O-rings are widely used in sealing applications. Review this O-ring seal simulation to discover what kind of nonlinearity the simulation demonstrates.  #### (2) Large strain necking of a tensile bar specimen

The tensile test is a basic testing method to obtain many mechanical properties of materials, like Young’s modulus, Poisson's ratio, yield strength and tensile strength. Check this simulation and try to discover what type of nonlinearity it demonstrates. How will removing these nonlinearities influence the force–displacement result? (Note that due to symmetry, only one-quarter of the specimen is modeled).  #### (3) O-ring seal with fluid pressure

Review this O-ring seal with fluid pressure simulation. Try to identify the geometry, material and contact nonlinearity in the model. #### (4) Snap-fit buckle

This model simulates the process of snap-fit buckle parts interlocking. What is the main source of nonlinearity?  #### (5) Cylindrical column local buckling analysis

Buckling is a form of structural instability where a small increment of load causes a very large increment in deformation. This simulation illustrates nonlinear buckling analysis on a ring-stiffened cylinder. Take a look at the model and tell what types of nonlinearity does buckling introduce?  ### Homework

#### (1) Cold rolling

Cold rolling is a process of feeding metal sheets through rollers to compress the thickness at a temperature lower than the recrystallization temperature (usually room temperature). This simulation illustrates the process of cold rolling of aluminum. Follow the instructions in the documentation to reproduce the analysis with and without plasticity. Compare these results and try to answer the following questions:

a. Which types of nonlinearities can you identify in the model with and without plasticity?

b. Why is it essential to include plasticity in the material model? Consider the following points: maximum stress, permanent deformation and the reaction force at the roller.  