Electricidade de Portugal, Lisbon,
Research metallurgistassociate professor, Centro de Mecânica e Materiais das Universidades de Lisboa (CEMUL)Instituto Superior Técnico, Lisbon,
Tension tests performed at constant crosshead speed have been simulated in a computer, and stress-strain, load-displacement, and strain rate-strain curves in uniform deformation under various testing conditions were obtained. Hart's phenomenological description of the plastic deformation was used together with a simple form for the stress and strain rate dependence of the material parameters that appear in this description. Various materials were simulated and the effects of crosshead speed, initial “hardness” state, specimen dimensions, and machine stiffness were studied in each case. The implications of these results in the specification and interpretation of tension tests are discussed. Particular attention is given to the relation between the onset of plastic instability and the point of maximum load in the tension test.
Paper ID: JTE10221J