Issue 33

A. Winkler et alii, Frattura ed Integrità Strutturale, 33 (2015) 262-288; DOI: 10.3221/IGF-ESIS.33.32 276 Fig. 19 is a micrograph of the fracture surface on a specimen made of POM tested in uniaxial fatigue. The damage initiation and the subsequently forming voids in the centre portion are clearly visible (the little black spots), the distance between beach marks growing larger and larger as the fatigue process progresses radially outward. Figure 19. Fatigue fracture in a POM tensile specimen. Figure 20. Void in the bulk of a plastic component as a result of cyclic loading. Fig. 20 shows a void inside the bulk of a component subjected to cyclic loading. The initial morphology was homogenous with no voids present after the manufacturing process. The void was detected after complete rupture of the component in a duty cycle test.