This lecture covers the fracture mechanics of materials, including the energy balance approach, stress intensity factor, Weibull model for brittle solids, elastic-plastic fracture mechanics, crack growth, and time-dependent fracture. It also discusses fracture in ductile materials, rubber testing, viscoelastic fracture mechanics, and craze-mediated fracture in polymers. The lecture concludes with topics on high-speed testing, heterogeneous media, and practical exercises for the end-of-term test.