Equivalent thermal expansion coefficients of lumped layer in laminated composites

Lumping a group of plies into a single layer to reduce the size of the problem and to increase the efficient computation is often used in thick composite structural modeling. In doing so, the use of equivalent properties for replacing the lumped heterogeneous medium by an equivalent homogenous material is required.The present study focused development of the equivalent coefficients of hygrothermal expansion of lumped layer by taking into account for induced curvature and shear deformation for an unsymmetrical and/or unbalanced layers lumping.The results of the ply stresses obtained by using the present model were almost exactly the same as the results obtained by using a full model for most of the cases studied.