Composite plates and panels are used in aerospace, marine structures, bridges and other structural applications, where they offer mass reductions over conventional materials which is a key industrial objective. The main purpose of this paper is to study the effect of shear direction on the buckling behaviour of composite plates under combined in plane compressive and shear loads. In pure compression the nodal lines (i.e. lines of zero out of plane displacement) are skewed due to the anisotropic characteristics of the laminate. When shear load is applied the skewing of these nodal lines can be increased or decreased according to the shear load direction, with consequent decrease or increase of the critical buckling load. The study uses the exact strip analysis software VICONOPT [1] which has the capacity to carry out buckling, postbuckling and vibration analysis and optimum design for prismatic composite plate assemblies. Critical buckling loads are firstly found for composite plates under different combinations of loads, and the finite element software ABAQUS/Standard [2] is used for validation. Examples for flat plates and stiffened panels with different aspect ratios and stiffener sizes are used for comparison. Finally composites are designed to minimize panel mass subject to critical buckling constraints involving specified loading combinations.

References

[1] Kennedy, D and Featherston, CA, 2010. Exact strip analysis and optimum design of aerospace structures. Aeronautical Journal, 114(1158), pp. 505-512.

[2] DS Simulia Inc. (2010). ABAQUS Standard Manual (version 6.10).