Effect of Stacking Sequence on Compressive Strength Reduction of Aircraft Composite Structures

摘要

Compressive strength reduction of composite structures due to notches or impactdamage is an important factor for aircraft structure design. Compressive strengthreduction is caused by stress concentration around notches such as skin manholes orimpact damage due to tool falling during manufacturing. In particular, the compressivestrength reduction due to the edge-on impact is large, so it is one of the most importantissues for strength design of the aircraft.In this study, in order to evaluate the effect of stacking sequence on compressivestrength after edge-on impact, edge-on impact survey test and compression after edgeonimpact test using CFRP laminates with different stacking sequence wereconducted. As a result, in the Soft laminate, including many ±45°plies, cracks due toedge-on impact spreading in the laminate thickness direction could be observed, anddetectability of the damage was better than that of other specimens. And the residualstrength after edge-on impact was improved in Hard3 laminate which retainedlaminate stiffness along the loading direction while suppressing the edge-on impactenergy that necessary to apply the dent depth equivalent to the barely visible impactdamage (BVID). These results show the possibility of improving the compressiveresidual strength by the optimization of stacking sequence.