Prediction of B-Pillar Failure in Automobile Bodies

The B-pillar is an important load carrying component of any automobile body. It is a primary support structure for the roof, and is typically a thin-walled, spot-welded, closed-section structure made from high strength steels. As part of the validation process, the B-pillar can be ex-perimentally loaded at quasi-static rates until failure†. The force and displacement of the impactor are measured to get valuable insight into the stiffness characteristics of the structure.

During the past two decades, crashworthiness simulation of automotive structures has proven to be remarkably good, largely because the finite element codes being used can accurately predict the plastic bending and stretching deformation mechanisms that occur in stamped metal parts. Abaqus/Explicit offers a general capability for predicting the onset and evolution of damage in ductile metals. The Müschenborn-Sonne forming limit diagram (MSFLD) damage initiation criterion allows for the prediction of necking instability in sheet metal. When combined with appropriate damage evolution criteria, sheet metal rup-ture initiated by necking can be captured in an Abaqus/Explicit simulation. In this Technology Brief, the MSFLD criterion is employed to investigate the failure of a B-pillar structure. Abaqus/Explicit results are shown to match well with experimental data provided by BMW.