Help Understanding and defining required plasticity parameters of aisi 3140 Steel

[RDelaCourt513]

Hello,


I am analysing a tubular-frame chassis collision using the explicit dynamics solver on Ansys.


I have sufficient data regardign the 3140 steel properties as you would expect. However I want to explore the deformation and I want to allow the structure to deform to try and give a best possible simulation result.


Aside from the density, Youngs modulus, Tensile and Yield strength what should I bring in to explore the plasticity characteristics. From what I have seen, I need to define the material surface finish, and either the Johnsons cook strength, multi-linear or bi-linear isotropic characterstics. Is this true.


I understand for things such as johnsons cook strength requires testing. Could someone please advise me on this and what would be the best approcah to take.


Thank you


Ryan

 

[Metalero]

You need to measure and / or calculate parameters that represent the plastic behavior of the metal.

There is a range of the most commonly used models for plastic strains of metals. These include a bilinear plasticity model, tabulated definition of plastic strains and many others. It is true, however, that most of these models do not take into account the kinematic strengthening phenomena. In other words, no effects of strain intensity on the yield strength are taken into account. Besides, high strain rates may cause adiabatic heating of metal in the greatest strained region and, therefore, its local softening.

The Johnson–Cook model is the most attractive among well-known plastic strain models. This model takes into account both kinematic strengthening and adiabatic heating of the material undergoing strains. However, difficulties exist with determining the parameters of this model. (LINK)