Development of Universal Test Method to Evaluate the Plastic Deformation of Sheet Metal

Universal test method to evaluate sheet metal formability was developed using finite element method based on axiomatic design. The newly developed formability test intended to generate the various modes of deformation and to control the onset of failure independently under each mode of deformation. The functional requirements (FRs) and the design parameters (DPs) of the test system were defined on axiomatic design approach and decomposed until the design reaches final stage. The independence axiom was applied throughout the design process to maintain the hierarchical independence of the formability test system. The flow diagram representing the system architecture was introduced after decomposition to give a help to establish the systematic design procedures and to determine the design parameters. Numerical simulation was carried out to determine the specific value of DPs which satisfies the FRs. Numerical results showed that modes of deformation varies accompanying various strain paths and good controllability of sheet forming is obtained for different kinds of materials. Experimental work was finally conducted to validate the proposed design. Stamping results represented that the outcome of the deformed geometry and strains are in good agreement with the numerical results.