With increasing requirements on the reliability of crash simulation it becomes more and moreimportant to model damage behaviour of structural components in crash simulation. Theapplication of new light weight materials makes damage modelling more difficult since thedamage behaviour of these materials is not well-known and many of them show a higherstrength but lower ductility in comparison with conventional materials. This workdemonstrates that damage behaviour of metallic materials depends strongly on stresstriaxiality and cannot be modelled with simple damage models based on one constantfracture strain. A systematic investigation was conducted to develop a damage concept tosimulate crash behaviour of magnesium, aluminum and steel components. To vary the stresstriaxiality notched flat tensile specimens and Iosipescu shear specimens were tested.Damage mechanisms were characterized by fractographic investigation. To verify the applieddamage models three-point bending tests on different automotive components likemagnesium instrument panel beams and B-pillars of a high strength steel were performedunder static and dynamic loading. The micromechanical Gurson model and thephenomenological Wilkins model were applied to simulate the different specimen tests andcomponent tests. It was found that the phenomenological damage model and themicromechanical Gurson model describe the influence of stress triaxiality on damagedevelopment. However, the phenomenological model requires more experiments than themicromechanical model. A weakness of the Gurson model is that it does not describe shearfailure. An extension of this model based on the Gologanu model has been made. Besidesinfluences of loading type and strain rate the element-size dependence of the damageparameters has to be taken into account in component simulations. A practical method wasused to calibrate the element-size dependence of the Gurson parameters. Another examplefor the application of the damage models is the precise prediction of load-bearing capacity ofspotwelds.
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