In vehicle bodies, bonding has become established for joining a wide variety of materials. However, to date there is no generally applicable method for analyzing the adhesive joint fatigue. In tests performed, a pronounced cohesive crack propagation phase was observed in epoxy layers with high local stress, resulting in high fatigue life differences between crack initiation and total failure. In order, to take this into account, the failure criterion was extended from initiation of technical crack to a local cracked zone.
A new method for determining the utilization degree of cracked zones was developed and calibrated based on experimental S/N curves. Recently, the stand-alone application ClaRP has enabled automatic damage assessment and thus the analysis of adhesive layers in complex finite element models.
Presenter: Manuel Frank | Engineer, Magna Powertrain
Featuring FEMFAT by Magna Powertrain, available through the Altair Partner Alliance