Constitutive modeling of anisotropic deformation and failure properties under monotonic loading

Shen, Fuhui; M√ľnstermann, Sebastian (Thesis advisor); Tekkaya, A. Erman (Thesis advisor); Lian, Junhe (Thesis advisor)

Aachen : RWTH Aachen University (2022)
Dissertation / PhD Thesis

Dissertation, RWTH Aachen University, 2022

Abstract

The accurate description of deformation and failure behavior of metallic materials is of significant importance for the safety and integrity of structural components as well as the manufacturing and forming industries. A methodology is developed in this dissertation to quantitatively characterize the anisotropic effects on the plastic deformation, localization as well as ductile damage and fracture properties of two distinct types of steels using phenomenological models. A new constitutive model is developed to describe the coupled interaction between thermal and anisotropic effects on the plastic flow properties in different high-strength low alloyed steels, which show the non-monotonic temperature dependence of strength because of dynamic strain aging effects. The influence of flow rule as well as hardening law on the prediction of plastic localization in an anisotropic ferritic stainless steel has been quantitatively evaluated. A phenomenological anisotropic damage mechanics model, which integrates non-associated flow rule and anisotropic hardening law, is developed to predict the individual effects of stress state and loading orientation on ductile damage and fracture behavior of a high-strength low alloyed steel. The experimental and numerical results obtained in this study have demonstrated that evolving features of anisotropy are of significant importance to achieve the accurate description of deformation and failure properties of the investigated materials. In addition, the application of non-associated flow rule as well as anisotropic hardening law is also an efficient approach to improve the accuracy of numerical simulations. With the straightforward parameter calibration procedures and high prediction efficiency, the proposed models and methodology can be used to describe the deformation and ductile failure properties of other metallic materials, such as some advanced high-strength steels and aluminum alloys, considering the effects of stress state, loading orientation and temperature.

Institutions

  • Division of Materials Science and Engineering [520000]
  • Integrity of Materials and Structures Teaching and Research Area [522520]