Reply To: NON LINEAR BUCKLING ANALYSIS H BEAM

[dlooman]

The APDL Materials Reference gives the example input below for temp-dependent bilinear isotropic hardening.  You appear to have only specified the yield stress.  Perhaps a shell element isn't the best choice for a plasticity analysis.  Perhaps a thin solid with several elements through the thickness would be more accurate.   

/prep7
MPTEMP,1,0,500            ! Define temperatures for Young's modulus
MPDATA,EX,1,,14E6,12e6           
MPDATA,PRXY,1,,0.3,0.3
TB,PLAS,1,2,,BISO         ! Activate a data table
TBTEMP,0.0                ! Temperature = 0.0
TBDATA,1,44E3,1.2E6       ! Yield = 44,000; Plastic Tangent modulus = 1.2E6
TBTEMP,500                ! Temperature = 500
TBDATA,1,29.33E3,0.8E6    ! Yield = 29,330; Plastic Tangent modulus = 0.8E6