A General Introduction To Fracture Mechanics and Mechanical Strength of Materials Or : Why do things break and what can we do about it ?

This report contains lecture notes of an introductory course on fracture mechanics and strength of brittle materials The course was presented at Philips Passive Components Roermond within the framework of the larger Cecopas course which deals with many aspects related to the development processing and perfor mance of passive components We start with the basics of fracture mechanics theory and from this theory it becomes clear which properties of a material deter mine its strength In subsequent sections methods for measuring these properties are presented In particular ways of determining strength Young s modulus fracture toughness aw distribution and residual stresses are discussed A separate section is devoted to indentation techniques In addition we give attention to the in uence of microstructure on strength and fracture behavior Other subjects dealt with are slow crack growth thermal shock and high temperature behavior Having explained why things break we then continue with a dis cussion of methods of strengthening components Also two sep arate sections are included on fractography and numerical simu lation two indispensable tools for analyzing and solving strength problems Since the course is intended to be only a general introduction some suggestions for further reading are given at the end