A micromechanics elastic–plastic constitutive model for sintered stainless steel fiber felt

Sintered stainless steel fiber felt (SSSFF) is a type of cellular material promising for functional and structural applications due to high porosity, controllable permeability, and high specific surface area, etc. In this study, a micromechanics elastic–plastic constitutive model was proposed for accurate representation of material behavior of SSSFF. Firstly, microscopic geometric structure was investigated and representative volume element (RVE) was established according to the reasonable simplifications and assumptions. Secondly, fundamental equations of elastic theory including equilibrium equations and geometric equations were built. Principle of virtual work and generalized Hook’s law were applied to obtain the elastic behavior. The incremental theory was adopted to derive the plastic stress–strain relations. Thirdly, the elastic and plastic relations were unified by statistical theory considering the fiber length and fiber orientation distribution. Finally, four SSSFF materials were introduced as numerical examples and the numerical results show good agreements with experimental results. The proposed micromechanics constitutive model, also expected to be applicable to other metal fiber sintered materials, is beneficial to predict the mechanical properties of sintered fiber materials and guide the material design.