The Research On Stress Intensity Factor Of Metal Graded Materials

The metal graded material manufactured by laser-forming technology is an innovative variety oflord load-carrying structural material whose components can be reasonably distributed throughuniform transitions without interfacial connectivity. Various efficient innovative structures can berealized through proper distributions of metal graded material in terms of the requirements forstrengths, stiffness, service lives and even functions. Therefore, the metal graded material isincreasingly applied in the fields of aeronautics and astronautics. In contrast, the industrialapplications of metal graded material are substantially restricted by the poor studies on mechanicalcharacteristics which considerably lag behind the advanced manufacture technologies. During theperiods of manufactures and servicesa large number of micro cracks will inevitably initiate andpropagate in the interior of metal graded material, which considerably degrade its mechanicalproperties. Therefore, it is of large practical significance that conducting researches on the fracturecharacteristics of metal graded material for dependable employments, optimization designs andstructure analysis.In the article, the researches on fracture problems of graded materials are reviewed，including thetheoretical analysis, numerical simulation and experiments characterization.Then describes the basictheory of the interaction integration method which is used in this paper to calculate the stress intensityfactor.Then introduces the characteristics of the continuity model and micro-mechanical model，andexplains how to use the models during calculating the stress intensity factor of interaction integrationmethod. Then，the problems of metal graded meterial plane with different types of crack, such as aedge horizontal crack, edge inclined crack and center-crac, a center crack with an edge crack aresimulated and analyzed by finite element method and interaction integration metho, and havecalculated the stress intensity factor and discussed the various paramenters which can have influenceon the stress intensity factor, and prospected the metal graded material’s future.