umat subroutine

Thermoplastic polymers are materials composed of long molecular chains primarily consisting of carbon. These polymers possess the unique ability to be shaped and molded under heat and pressure while retaining their stability once formed. This high formability makes them widely used in various industries, including furniture production, plumbing fixtures, automotive components, food packaging containers, and other consumer products. This package introduces a thermodynamically consistent damage model capable of accurately predicting failure in thermoplastic polymers.  The implementation of this model is explained through the use of an ABAQUS user material (UMAT) subroutine. The package is structured as follows. The introduction section Provides an overview of thermoplastic polymers and their mechanical properties. In the Theory section, the constitutive damage model and its formulation are reviewed. Then, an algorithm for numerically integrating the damage constitutive equations is presented in the Implementation section. In the UMAT Subroutine section, a detailed explanation of the flowchart and structure of the subroutine is provided. Finally, two simulation examples, namely the T-fitting burst pressure test and the D-Split test, are performed and the obtained results, are investigated. Notice: Software files and A full PDF guideline (Problem description, theory, ...) are available; Videos are coming soon.