Local buckling for triangular and lemniscate delaminations near the surface of laminated cylindrical shells under hygrothermal effects

In this paper, an energy method is applied to study hygrothermal effects on local buckling for different delaminated shapes near the surface of cylindrical laminated shells. The sub-laminated shell (delaminated region) is monolayer or multilayer. The effect of non-linear buckling for local delamination of cylindrical laminated shells is obtained by considering transverse displacements of sub-laminate shells. The Young’s modulus and the thermal and humidity expansion coefficients of the material are treaded as functions of temperature change in the cylindrical laminated shells. From example calculations, the relationships between critical strain value and the geometrical and physical parameters of cylindrical laminated shells and sub-laminated shells are investigated.