Abstract:

ESDU 88015 introduces a program in Fortran, provided as ESDUpac A8815, for calculating the wrinkling loads of balanced, and two classes of unbalanced, laminated face plates under uniaxial or biaxial loading. Symmetric or antisymmetric wrinkling modes are considered and account is taken of the two orthogonal shear moduli and the through-thickness modulus of the core, together with the panel dimensions. The input to the program is detailed, and the face plate properties can be provided as layer properties with a stacking sequence or directly as face plate stiffness matrix values. The output includes the wavelength of the wrinkles both along and across the panel. Graphs are included to illustrate the influence of the major variables on wrinkling loads. The face plate/core adhesive layer can significantly affect the wrinkling load, and that effect is allowed for in the program. The program checks that input values comply with the limits to the analysis and the program terminates, providing an appropriate explanation, when those limits are not met. Program testing is briefly outlined, and several worked examples illustrate its use.