Determining Parameters of Piecewise-Linear Metal Models based on Flat Specimen Testing Results

The paper deals with a methodology of determining parameters in piecewise-linear plasticity models of metals, which are used for stress-strain analysis and failure prediction in mechanical engineering structures. We present a method for identifying parameters of piecewise-linear metal models that involves a transition from no-minal (also known as engineering) stresses and strains to the true values. Our method boasts the following distinctive features: accounting for the stress-strain state in the specimen neck and guidelines for determining intermediate parameters of material models. We simulated tensile testing of flat specimens numerically in the ANSYS LS-DYNA software package. The computation used model parameters for steels 20 and S235JRG2, which are common in passenger transport vehicles. The computational error for relative tensile strain in a specimen at the moment of failure did not exceed 2,8 %

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