Issue 41

V. Rizov, Frattura ed Integrità Strutturale, 41 (2017) 491-503; DOI: 10.3221/IGF-ESIS.41.61 500 dimensional form along the crack front for two 1 0 / B B ratios at 1 / 2 0.75 h h  and 2 0 / 2 B B  . Only the right-hand half of the crack front is shown in Fig. 5 since the distribution is symmetrical with respect to the crack front centre. The horizontal axis is defined such that 1 2 / 0.0 y b  is in the crack front centre. Thus, 1 2 / 1.0 y b  is in the right-hand lateral surface of the beam. One can observe in Fig. 5 that for 1 0 / 1.2 B B  , the J -integral value is maximum in the crack front centre and decreases towards the right-hand lateral surface (this is due to the fact that for 1 0 / 1.2 B B  the material property, B , is minimum in the crack front centre and increases towards the beam lateral surfaces). Fig. 5 shows that for 1 0 / 0.4 B B   , the J -integral value increases from its minimum in the crack front centre towards the right-hand lateral surface of the beam. Figure 5 : The distribution of the J -integral value in non-dimensional form along the crack front (curve 1 - at 1 0 / 1.2 B B  , curve 2 – at 1 0 / 0.4 B B   ). The effects of the material gradient and the crack location on the strain energy release rate are evaluated too. For this purpose, calculations of the strain energy release rate are carried-out by using formula (22). The strain energy release rate is presented in non-dimensional form by using the formula,   0 / N G G B b  . Figure 6 : The strain energy release rate in non-dimensional form plotted against 1 0 / B B ratio at three 1 / 2 h h ratios.