A Study of Interface Crack Branching in Dissimilar Anisotropic Bimaterial Composites Including Thermal

Interface crack;Branching;Dissimilar;Anisotropic;Bimaterial composites;Thermal effects

Li, Renfu ; Aerospace Engineering

University:Georgia Institute of Technology

Department:Aerospace Engineering

关键词: Interface crack;    Branching;    Dissimilar;    Anisotropic;    Bimaterial composites;    Thermal effects;   

Others  :  https://smartech.gatech.edu/bitstream/1853/4893/1/li_renfu_200412phd.pdf.pdf

美国|英语

来源: SMARTech Repository

【 摘 要 】

The interface crack branching phenomena, including thermal effects, has been investigated by using complex variable method and Stroh's dislocation theory, extended to thermo-elasticity inmatrix notation. As one of the most catastrophic failure modes in structures like laminated andsandwich composites in aerospace andmarine construction, thin film in electronic packaging,rotatorsin high speed engineofaircraftand reactor innuclear power station, thestudyofinterface crack branching has become a topic notonly havingtheoretical importance, butalso havingpractical significance. A unifiedapproachispresented toaddressthethermoelastic interface crack problems in dissimilaranisotropic bimaterial composites, anda compact closed form solution is formulated by analytical continuation principle of complex analysis. Employing the contour integral method, an explicit solution tothe interactionbetween the dislocations and the interface crack is obtained. By modeling the branched portion as a continuous distribution of the dislocations, the thermoelastic interface crack branching problem is then converted to a set of semi-coupled singular integralequations andsolvedbyGauss-Jacobi integration schemes. The influence of material property mismatches betweenthetwo constituents and the thermal loading effects on theinterfacecrack branching are demonstratedbyextensivenumericalsimulation. Some useful criteria for predicting the interface crack branching growth and guidance for optimal composites design are suggested. Further, acontact model toeliminate the overlapping between the two surfacesofaninterface crackisalsoproposed and some new parameters which could influencetheinterpenetrating phenomenaarealsodiscovered.Thetechnique toextendthe current method to three dimensional problems is also outlined. Furthermore, the C++ source code has been implemented to manipulate the complicated complex operations for numerically solving the singular integral equations in complex matrix form.