Influence of variable scattering on the optimum winding angle of cylindrical laminated composites

Cylindrical laminated composites are generally made with a fibre winding an gle equal to 55 degrees. In this paper the authors show, by using reliabili ty analysis of a [+/- alpha](n) filament wound composite, that the optimum fibre winding angle can vary hugely with the scattering of some design vari ables. Studied structures are pressure vessels and axially loaded pressure pipes. The stresses are computed using the classical laminated membrane the ory and the Tsai-Wu failure criterion is adopted as the limit state functio n of a ply. Numerical results show that the Young's modulus of the matrix a nd the transverse strength of the ply are the most important design variabl es. The amplitude of the applied pressure and the axial force also modifies the optimum winding angle. (C) 2001 Elsevier Science Ltd. All rights reser ved.