ABSTRACT
Fracture testing of plastics, composites, and ceramics is relatively new, however, and there are a number of unresolved issues. This chapter briefly summarizes the current procedures for measuring fracture toughness in plastics, fiber-reinforced composites, and ceramics. It outlines some possible approaches for taking account of viscoelastic behavior and time-dependent yielding in fracture toughness measurements. The chapter discusses that the apparent thickness dependence of fracture toughness in metals is a result of the mixture of two fracture morphologies: flat fracture and shear fracture. It discusses the shortcomings of the traditional American Society for Testing and Materials (ASTM) E399 test procedure and validity requirements when applied to metals. The chapter outlines a few suggestions for inferring crack tip parameters that take into account the time-dependent deformation of engineering plastics. It discusses that ASTM has published a number of standards for fracture testing of metals.
