TESTS OF LONG PLATES UNDER BIAXIAL COMPRESSION

A plate test rig has been modified to apply biaxial compressive loads to rectangular plates. Attention was paid to defining boundary conditions and ensuring that loadings were correctly measured. Test plates were of 6 mm thick high-yield structural steel, containing residual stresses and initial out-of-flatness. Tests measured the effect of small transverse stresses on the longitudinal strength. The plate strengths obtained are compared with small-scale tests, finite-element and finite-difference strength analyses, and present and proposed design rules. The use of a single strength interaction curve is seen to create problems in formulating design rules. Tests are also reported on plates under uniaxial loading with unloaded edges constrained to remain straight.