HMH perfectly plastic material

Implements a perfectly plastic material. HMH plasticity condition with no hardening is used. Before plastic condition apply, and during unloading and reloading an isotropic linear elastic behavior is assumed. Linear elastic behavior is described using Young modulus and Poisson ratio. Plasticity condition is described using uniaxial strength. The model description and parameters are summarized in table 5.

Table 5: HMH perfectly plastic material - summary.

Description	HMH perfectly plastic material
Record Format	Steel1 num(in) # d(rn) # E(rn) # n(rn) # tAlpha(rn) # Ry(rn) #
Parameters	- num material model number
	- d material density
	- E Young modulus
	- n Poisson ratio
	- tAlpha thermal dilatation coefficient
	- Ry uniaxial strength defining the yield limit
Supported modes	3dMat, PlaneStress, PlaneStrain, 1dMat, 2dPlateLayer, 2dBeamLayer, 3dShellLayer 3dBeam, PlaneStressRot