SOLIDWORKS Premium-Nonlinear

Introduction - The basics of nonlinear analysis are explained. This starts with describing what a nonlinear analysis is, the types of nonlinearities that can occur and how these differ compared with a linear analysis. An overview of how the solver carries out the analysis is also provided which outlines some of the complexities involved. A summary about the various material models is also provided e.g. plasticity, hyperelastic (rubber) and hardening.

Lesson 1: Large Displacement Analysis - This introduces the concept of pseudo-time when fixtures and forces are applied etc. The linear vs nonlinear results for a 360° rotation applied to a simple jubilee clip example are compared. The nonlinear study properties are also explored to gain confidence with knowing what they do.

Lesson 2: Incremental Control Technique - The difference between force and displacement control techniques is explained using a trampoline example. Understanding the different setup requirements (for fixtures & loads etc.) and what study properties are needed for each type is also covered.

Lesson 3: Nonlinear Static Buckling Analysis - The arc-length control technique is explained using a curved plate (salsa jar lid) example. The snap-through snap-back characteristic is also described and why this requires a nonlinear buckling analysis. Differences between linear and nonlinear buckling analyses are compared, as well as the importance of not using symmetry as a boundary condition.

Lesson 4: Plastic Deformation - The effects of plasticity are investigated using a load-unload cycle on a paperclip example. Above yield stresses are generated which produces a permanent set (plastic deformation) after the load is removed.

Lesson 5: Hardening Rules - The Bauschinger effect is observed when above yield stresses are generated in both directions (tension-compression) when a fully reversed load cycle is applied to a crank arm example. This involves using the hardening factor to show the differences between kinematic and isotropic hardening.

Lesson 6: Analysis of Elastomers - The hyper elastic Mooney Rivlin material model is applied to a rubber pipe with an internal pressure. Special material inputs are discussed alongside how to access these within the standard set of SOLIDWORKS library materials. A method of backchecking the curve fit against the result is also shown.

Lesson 7: Nonlinear Interaction Analysis - The advantage of applying stabilisation points (as prescribed displacements) is discussed using a rubber tube example that slides over two metal stops. Observations are made to explain how this helps to control the movement during each time step which allows the solver to run to completion.

Lesson 8: Metal Forming - A 2D analysis with symmetry is utilised for a nonlinear plasticity material model which contains a sliding (contact) interaction where a plate is bent in a press machine. Various study properties are discussed to help the solver reach completion, as well as the recommendation to use the large strain formulation option (true stress / true strain) when the strain is above 4%.