Fracture and Fatigue analysis in piezoelectric structures with multiple discontinuities using Extended Finite Element Method

Abstract

In this thesis, numerical simulation of 2-D cracked piezoelectric problems under thermoelectro-mechanical is done using XFEM approach. For the better understanding of fracture newlineparameters such as intensity factors (IFs), many benchmark problems have been solved using newlinethermal interaction integral technique in conjunction with Stroh formalism. Various parameters newlinelike effect of crack orientation, crack length, inter-crack distance have been taken for analyzing newlinedouble edge-cracked piezoelectric domain under applied mechanical, electrical and combined newlinethermo-electro-mechanical loadings to observe the variation of SIFs values. newline To check the accuracy and computational cost, the numerical results obtained from XFEM newlineapproach are being validated with the results of analytical method. The effect of newlineelectromechanical coupling in cracked piezoelectric structure under applied different loading newlineenvironment is observed using proposed enrichment functions by implementing XFEM newlineapproach. A set of generalized basis functions has been implemented in XFEM for piezoelectric newlinematerials that show convergence in intensity factors with the exact solutions of Griffith s crack. newline The XFEM approach has been applied to the crack growth problems by incorporating FEM newlinewithout the concept of remeshing. Therefore, quasi-static fatigue crack growth study is also done newlinein 2-D finite cracked-piezoelectric domain under thermo-electro-mechanical loading newlineenvironment. The crack growth angle is calculated by the anisotropic fracture toughness newlineparameter and the principle of modified hoop stress intensity factor. Numerical simulation of newlinefatigue crack growth is done for piezoelectric materials with multiple discontinuities under the newlineapplied mechanical, electromechanical and combined thermo-electro-mechanical loadings newlineenvironment. The present numerical results obtained from XFEM approach are in good newlineagreement with the existing literature. newline