To properly simulate analyses that fall under these “what if” scenarios, the Non Linear material model should be used.
Note: The Nonlinear Elastic model will account for material behavior up to the yield point. In cases where the post yielding behavior (Y to X) is needed, the elasto-plastic model can be used. In the next blog for this series, we will talk about the 3 different Plasticity types which are Von Mises, Tresca, and Drucker Prager.
To be able to use the nonlinear elastic model, a stress-strain graph must be defined within SOLIDWORKS Simulation. This can be done by selecting the “Create stress-strain curve” on the material properties window. You can then input stress strain points to create the graph.
For this material model to work, a continuous stress-strain curve should be plotted. This basically means the points should either be continuously increasing or decreasing in value. At times, data from physical material testing can provide points where the strain or stress point in value due to apparatus tolerance. These points should be omitted when being inputted into the program.
A stress-strain curve can be defined in tension and compression, thus representing different material behavior to under tensile and compressive loads. If the compression portion of the curve is not specified, SOLIDWORKS Simulation will automatically assume that tension and compression would have to respond similarly.
Besides the stress strain curve, the material model will also need other properties such as Poisson’s ratio and mass density. The tensile strength is not required, but recommended. If the simulation has any thermal loads involved, a thermal expansion coefficient (CTE) can also be input. The nonlinear material model also allows for the CTE, Poisson’s ratio and density to be temperature dependent, giving you more accurate results!