Influence of stiffener configuration on post-buckled response of composite panels with impact damages

Numerical FEA parametric analysis of CAI behaviour of CFRP stiffened panels

“…Even though stiffened panels CAI numerical studies have been undertaken by many researchers [3], [9], [14], [17], [18], [22]- [26], the inefficient convergence behaviour of the CZM method is emphasised in many studies [9], [14], [18], [22], [24], [26]. In this paper, parametric analyses were conducted to investigate the optimum CAI modelling strategy and the effect of the critical parameters involved on the accuracy and computational efficiency.…”

“…The required number of cohesive zones that lead to an accurate simulation was questioned. In similar CAI studies, the most common method is to use cohesive elements in the interface between the skin and the stiffener as shown in figure 10 [3], [9], [17]. On the other hand, in impact studies, cohesive elements may be applied even between all the adjacent plies [34], nevertheless, the scope of these is different to the CAI simulations.…”

“…OMF is the ratio between the mesh size of the shell elements and the mesh size of the cohesive elements. In general, cohesive elements require a finer mesh to ensure the efficiency of the method [3], [9], [14], [35]. Different OMF were examined within the same model to investigate the importance of this particular parameter in the final results.…”

“…The structural performance is highly affected by the existence of a pre and/or post-service damage, or manufacturing inherited damage [8]. Damage can occur during maintenance by dropping of tools or due to hail or runway debris, which can lead to collapse due to disbond, delamination, matrix cracking and fibre fracture [9]. The resulting damage from impact events may be difficult to observe.…”

“…The main disadvantage of VCCT is the lack of damage initiation criteria [21] contrary to CZM, whose use has been recently boosted for predicting delamination growth. Despite of the method's increased application by researchers [3], [9], [14], [17], [18], [22]- [26] one of the main disadvantages of CZM is the reduced computational efficiency [9], [14], [18], [22], [23], [26]. Within the public domain literature, the need for further investigation in the modelling parameters of CZM application for increasing the accuracy and computational efficiency was evidenced.…”