Engineering analysis + design software

User Area > Advice

Defining Temperature Dependent Material Properties

  • All of the linearised hardening gradients (Ep) for the material data must be less than (not equal to) the initial elastic modulus (E)
  • All the temperature curves should have the same number of stress-strain coordinates defined
  • All the strain values used with their corresponding stress values for each curve should be identical
  • The difference between yield stress values for adjacent points on the same temperature curve should be as smooth as possible (i.e. not changing slope abruptly)
  • Negative plastic strain "increments" must be avoided
  • Ideally, curves that are basically identical throughout the whole strain range should be eliminated, e.g. in this case the curves at T=0 and T=20 are identical. This should not be a problem, but is a further possibility of small number problems when interpolating between "identical" curves
  • The C (=Ep/(1 - Ep/E)) values become numerically large when Ep approaches E (they equal infinity when Ep=E). This can cause round-off problems and some inexplicable convergence problems/odd results. LUSAS converts the Ep values from the data input into corresponding C values for use throughout the analysis 

innovative | flexible | trusted

LUSAS is a trademark and trading name of Finite Element Analysis Ltd. Copyright 1982 - 2022. Last modified: November 29, 2022 . Privacy policy. 
Any modelling, design and analysis capabilities described are dependent upon the LUSAS software product, version and option in use.