铝合金5052材料表征.doc

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Chapter 3 Material model and material characterization of automotive aluminium alloy 5052H34
preface
The basic property of material decides the use function of the the research of car crashes and large deformation of key components,the key point of solving the problem is to build corresponding physics-math model in order to acquire the specific material for the automotive aluminium alloy in our research ,we need to consider the response characteristic of the material machanism on condition of real impact (such as dynamic loading,high-stress condition,including primary defects or damage,etc) .By this way, numerous performance test and full-size componnet crash test need to be conducted ,which would exhaust great labor power and physical resources,but the result is still the limited discret data obtain by the experiment,it can hardly cover the space of all solution of the some extreme condition such as shearing stress condtion, high strain rate(ε－1≥2×102),it hard to predict its machanism response. Therefore,this model we built has its comparatively large combine with numerical simulations,it can expand the space of the model effectively,while obtain complete material parameters.
The result shows that the precision of numerical simulation is largely depend on the precision of material parameter to input. In the analysis of large deformation,mater
-ial machanism must describe the material change from elastic deformation,elastoplastic deformation,damage progession,evolvement,fracture,which is multi-step machanism procedure. Besides,various strain rate,anisotropic caused by processing history,etc need to be take into account to consider its affection with constitutive relations. Previously,this is a extremely complex project,where many problems is still unsolved. and ,etc simply used tensile bar experiment combined with finite element to simulate the characte