TABLE OF CONTENTS Notched axi-symmetric test pieces (AE for the French "axisym trique entaill e" are laboratory test pieces used to characterize fracture properties (mostly metallic) of materials. The stress level plays an essential role in ductile or brittle fracture initiation. Notched axi-symmetric test pieces with an experimental traction device (which is thus simple) allow us to reach locally stress levels somewhat larger than the yield strength of the material through a geometrical effect resulting in a stress tri-axiality ratio. This ratio is defined as the ratio of mean stress to Von Mises stress. Notched axi-symmetric test pieces constitute small structures. Mechanical tests are rather simple, but it is otherwise necessary to analyze stress and strain states by calculation of the structure. This is usually performed by finite element calculations.
In the following, the performance of experiments as well as the mechanical analysis of AE test pieces will be detailed. The two first parts will be devoted to experimental aspects: test pieces geometry, mechanical testing and observation of damage. It will then be appropriate to proceed with mechanical analysis. The elastic case and then various treatments of plasticity will be presented. These treatments will be the basis of brittle or ductile fracture analysis, which will be illustrated by short case studies. Creep damage will also be briefly covered.
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[1]Chapter written by Jacques BESSON.
A schematic representation of notched axi-symmetric test pieces geometry is given in Figure 10.1. The initial notch radius is denoted ?, the initial...
