Application of probabilistic fracture mechanics to a dynamic loading situation using the example of a dynamic tension test for ceramics

Abstract

Every acceleration or deceleration causes inertia forces and as a consequence elastic waves. Of course, such dynamic loading situations often occur in structural applications of materials. The consequences of such dynamic loading on designing with ceramics are considered on the example of a new dynamic tension test. First, the test device is described, and the resulting loading situation is carefully analysed. It is seen that the dispersive character of wave propagation causes an inhomogeneous stress distribution changing with time. Then the influence of the dynamic loading on the stress intensity factors of small cracks, which in general are responsible for failure in ceramic materials, is discussed. Finally, the consequences on fracture statistics are considered. Although the demonstrated procedure is restricted to not-too-steep ramps of the wave front, it is considered to be valid for most cases of dynamically loaded ceramic components. Exceptions are very sharp impact or ballistic loading.