Influence of curved delamination front on toughness of multidirectional DCB specimens

Mode I delamination toughness (GIc) of a laminated composite depends not only on the stacking sequence or indirectly coupling parameter of Dc=D122D11D22, but also on specimen geometrical ratios a0/b and a0/h. In this study, a non-uniformity ratio, β = (GImax − GIavg)/GIavg%, is introduced to take into account the influence of above factors on the energy release rate distribution along the width of double cantilever beam (DCB) specimens...