Abstract:

ESDU 94004 gives equations for the strains and stresses, and curvatures where appropriate, in laminated flat plates as a result of either loading actions or the differential contractions and expansions that occur due to temperature changes in the usual working environment or temperature change from the curing temperature to the working temperature, or a combination of both effects. The plates may be built-up from orthotropic layers having different material elastic and thermal properties, thicknesses, and orientations of their principal axes of orthotropy. The equations apply to balanced laminates, when no curvature will be induced by the thermal effects. They also apply to unbalanced laminates in which case equations give the stresses induced by thermal effects when the plate is held flat, either with or without an in-plane loading. Worked examples for the stresses in a balanced plate due to external loading and built-in stresses in the faceplate of a sandwich panel illustrate the use of the equations.