Damage analysis of fiber reinforced Ti-alloy subjected to multi-axial loading—A micromechanical approach

Effects of initiation and propagation of interface damage on the elastoplastic behavior of a unidirectional SiC/Ti metal matrix composite (MMC) subjected to multi-axial loading are studied using a three-dimensional micromechanics based analytical model. Effects of manufacturing process thermal residual stress (RS) are also included in the analysis. The selected representative volume element (RVE) consists of an r × c unit cells in which a quarter of the fiber is surrounded by matrix sub-cells. The constant compliance interface (CCI) model is used to model interfacial debonding and the successive approximation method together with Von-Mises yield criterion is used to obtain elastic–plastic behavior. Failure modes during multi-axial tensile/compressive loading in the presence of residual stresses are discussed in details. Results revealed that for more realistic predictions both interface damage and thermal residual stress effects should be considered in the analysis. Comparison between results of the presented model shows very good agreement with available finite element micromechanical analysis and experiment for uniaxial loading. Also, results are extracted and interpreted for equi-biaxial including transverse/transverse and axial/transverse and equi-triaxial loading.

► A 3-D model is presented to predict the elastoplastic response of SiC/Ti composite.
► Loading conditions include general uniaxial, bi-axial and tri-axial loading.
► Initiation and evolution of interface damage and plastic deformation are studied.
► Effects of manufacturing process thermal residual stress are considered in the model.