Discrete damage modeling of static bearing failure in laminated composites

Discrete Damage Modeling (DDM) of double shear lap bolted joint was performed. Regularized eXtended Finite Element Method (Rx-FEM) was used for the simulation of matrix cracking at initially unknown locations and in directions independent of the mesh orientation in a ply level 3D model. A set of input properties combining directly measured ply properties and properties empirically reduced from laminate level testing by using common industry practices was used for blind prediction of test data for 1.5D and 3.0D edge distance specimens with clamp-up. The simulations predicted the bearing strength characteristics for 1.5D configuration within 10% window, whereas for the 3.0D case the ultimate bearing strength was underpredicted by 20.3%. X-ray CT imaging of post-peak loaded specimens was performed. The observed failure modes and locations agreed with the experiment in most cases. A limited number of input parameters including fiber failure fracture toughness were varied in a parametric study.