INVESTIGATION OF CRACK-PROPAGATION IN CERAMIC CONDUCTIVE EPOXY GLASS SYSTEMS

The primary objective of this combined experimental and analytical stu dy was to investigate the mechanical behavior of glass/conductive adhe sive/Al2O3 systems with a surface notch, measure the properties of the system at various temperatures, implement these temperature dependent properties into a nonlinear finite element framework, and predict the initiation and growth of cracking, The three major tasks of this work include: (a) testing of fracture strength of the systems at three dif ferent temperatures, including the determination of thermal crack init iation and growth, (b) determination of basic thermal-mechanical prope rties of adhesive, glass, and Al2O3, respectively, and (c) identificat ion of appropriate quantities to predict damage modes, including initi ation and growth, at different temperatures and comparing the data wit h experiments, The major conclusions are as follows: (a) realistic non linear material properties are essential input for correct nonlinear f inite element modeling, (b) J-integral can be applied to predict the c rack initiation and growth for the material system considered, (c) eit her bulk glass material or the adhesive/glass interface may fail depen ding on the applied temperature and notch length, and (d) curved crack growth path inside the glass can be predicted by fracture mechanics.