Failure and strain field during testing of ultra high strenth steel

OPTUS II - Modelling of failure criteria based on micro-structure evolution in boron-alloyed steel

Published: 15 January 2010

Heat treatment and welding are very important industrial procedures in the manufacturing of boron-alloyed ultra-high strength components. Due to the temperature history in these processes and the mechanical properties of the sheet material will change. OPTUS II is a strategic project for a more general introduction of ultra high strength materials in automotive structures.

The aim of the research is to improve the capacity to simulate the influence of heat treated material distributed in components made of ultra-high-strength-steel sheet material. Strain and fracture at welds and heat treated component parts are studied on a small length scale and models for FE-simulation on a larger length scale are formulated. Experiments based on digital optical methods are used to study deformation fields and failure in the vicinity of holes and welds The developed methods and models will be used in product development of automotive structures, e.g. in bumper deformation analyses as well as full car crash analyses done by the automotive industry. The Ph.D. project is funded by VINNOVA within the FFI-programme. The research is also supported by funding from Ford University Research Programme (URP). The project is carried out in cooperation with Gestamp Hardtech, Volvo Cars and Ford Forschungszentrum, Aachen, Germany.

Research student: Stefan Golling
Supervisor: Mats Oldenburg
Assistant supervisor: Karl-Gustaf Sundin