This tutorial provides step-by-step instructions to create and analyze a double cantilever beam (DCB) model that uses the cohesive element functionality of Helius PFA. The problem consists of a unidirectional (fiber direction is parallel to long edge of specimen) composite beam that is fixed at one end and is divided by a layer of cohesive elements. Equal displacements applied in opposite directions on the free end of the beam force delamination to initiate at the free end and propagate towards the fixed end in a pure mode I fracture. The DCB dimensions and loading are shown below.
The beam uses CHEXA elements for the plies and CIFQUAD elements for the cohesive layer.
In this tutorial, step-by-step instructions are provided that cover the creation of the model and interpretation of the results. Elementary modeling details are omitted as it is assumed you have previous experience with the Patran environment. Please refer to the MSC Nastran or Patran documentation before completing this tutorial if you are unfamiliar with Patran.
A completed bulk data file (Tutorial_4_Nastran_Completed.bdf) for this tutorial is available for download here.