Experimental and finite element studies on buckling of skew plates under uniaxial compression

Abstract

Experimental studies were made on isotropic skew plates made of aluminum 7075-T6 and laminated composite skew plates under uniaxial compression with unloaded edges completely free and one loaded edge restrained completely and the other loaded edge restrained except translationally in the direction of loading. Experimental values of the buckling load have been determined using five different methods. The buckling load has also been determined using CQUAD8 finite element of MSC/NASTRAN. Comparison is made between the various experimental values of buckling load and the finite element solution. The effects of the skew angle and the aspect ratio on the critical buckling load of isotropic skew plates made of aluminum 7075-T6 have been studied. The effects of the skew angle, aspect ratio, and the laminate stacking sequence on the critical buckling load of laminated composite skew plates have also been studied. The critical buckling load is found to increase with the increase in the skew angle and decrease with the increase in aspect ratio. Method IV yields the highest value for critical buckling load and Method III the lowest value for critical buckling load. Among the various experimental values, the one given by Method IV is closest to the finite element solution, and the discrepancy between them is less than about 5% in the case of isotropic skew plates and about 10–15% in the case of laminated composite skew plates.

Keywords

• critical buckling load
• finite element analysis
• isotropic skew plate
• laminated composite skew plate