Development of User Subroutines in Commercial Software (UMAT and UEL in ABAQUS)

UMAT for graded elements (variable D matrix)

• Implementation of material gradient in D matrix
  
• Material properties determined directly at gauss points (GPs)
  
• Information needed are global coordinates of GPs and material function (e.g. exponentially graded Young's modulus, etc. )
  

UEL for cohesive elements (under development)

• Application to Reflective Cracking problem in pavements
  
• Application to FGMs