Mechanical testing and finite element modelling of aluminium alloy welds under high strain rate: initial results

TWI Industrial Member Report Summary  785/2003 

Mike Gittos and Guang Xu look at testing and modelling of aluminium alloy welds

Background

In recent accidents involving welded aluminium rail vehicles, some of the longitudinal welds had fractured for some metres beyond the damage zone, the panels themselves without significant distortion. Attention is not currently paid to the effects of strain localisation on the structural behaviour of the joint in design codes such as BS 8118:1991 'Structural use of aluminium' nor does it stipulate any requirements for fracture toughness. BS 7910:1999 which covers flaw assessments of metallic structures, does not provide guidance on material properties and loading conditions for crash situations. Strain rate should also be considered.

Objectives

• Assess strength and ductility of MIG and FSW welded joints in 6000 series aluminium alloys

• Develop finite element modelling methods for high strain rate applications