Structural Reliability of Thin Plates with Random Geometrical Imperfections Subjected to Uniform Axial Compression

It is generally known that the load carrying capacity of thin plate structures under axial compression are partially dependent on the initial geometric imperfections. Since these initial geometric imperfections are random in nature, the strength distribution will also be random. Hence a probabilistic approach is required for a reliable design of these thin plate structures. In this paper, by keeping the variance of imperfections of all the models at assumed manufacturing tolerance of 1.71 mm and maintaining the maximum amplitude of imperfections within ±8 mm, 1024 random geometrical imperfect plate models are generated by the linear combination of first 10 eigen affine mode shapes using 2^k factorial design. These imperfection models are analyzed using ANSYS non-linear FE buckling analysis including both geometrical and material nonlinearities. From these FE analysis results, the strength distribution of the plate is obtained and using Mean Value First Order Second Moment (MVFOSM) method, reliability analysis is carried out