Transient and cyclical hygrothermoelastic stress in laminated composite plates: Modelling and experimental assessment

The present paper is devoted to the modelling and the simulation of hygrothermoelastic stresses in composite laminated plates: the hygrothermal fields are established by employing the Fick’s law for transient and cyclical environmental conditions, then the classical laminated plate theory, adapted for taking into account such conditions, is used. The experimental assessment of hygrothermoelastic stresses is performed by measuring the deformation of unsymmetric plates and by adopting the fringe projection method, a full-field optical technique capable to reconstruct the deformed shape of stressed bodies, without any hypothesis on their displacement field. Measurements are performed for plates under pure thermal and transient hygrothermal solicitations. Good agreement is found between numerical simulations and experimental results. The experimental technique turns out to be useful also to identify, through the measurement of curvatures in unsymmetric plates, the thermoelastic properties of the material, coefficients of thermal and hygroscopic expansion.