Identificação de parâmetros materiais através da simulação numérica de um processo de estampagem profunda / Parameter identification based on deep drawing experiments

AUTOR(ES)

Robson Gonçalves Trentin

DATA DE PUBLICAÇÃO

2009

RESUMO

Numerical simulation of metal forming processes requires a constitutive model, which depends upon adequate material parameters. A direct determination of material parameters usually admits homogeneous stress and strain states in the specimen, thereby narrowing the application range to moderate deformations or even compromising accuracy in some industrial applications. Therefore, a combined experimental and numerical technique based on optimisation strategies is recommended. Such method is generally known as parameter identification and produces stress states close to those to be verified in industrial operations. In this work, a parameter identification technique based upon deep drawing experiments is presented. Sensitivity analysis is performed using a modified finite difference method, and the optimization itself is developed using quadratic programming. Sensitivity results using the classical and the modified finite difference methods are studied and compared, especially with respect to the application of automatic or imposed step increments. It is observed that the modified method yields a more effective behaviour with respect to the automatic time step strategy, allowing use of a wider range of penalization factors and attaining greater efficiency. Several identification problems are presented showing qualitative agreement with related research in the literature. Difficulties arise in the simultaneous determination of multiple material parameters, due to typical flat regions or to the presence of local minima in the design space, suggesting future combination of the presented approach with evolutionary algorithms.

ASSUNTO(S)

deep drawing análise de sensibilidade parameter identification estampagem profunda identificação de parâmetros sensitivity analysis engenharia de materiais e metalurgica

Documentos Relacionados

• Simulação do processo de estampagem profunda de corpos cilindricos atraves do metodo dos elementos finitos
• Estudo dos parâmetros de influência na simulação numérica de estampagem de chapas
• Influence of the lubricant use in the process of deep drawing with thick steel sheeet metals
• Parameter identification in civil structures.
• Modal parameter identification of structures and rotating machine by adaptative filter