Analytical investigation of composite sandwich beams filled with shape memory polymer corrugated core

Shape memory polymers (SMPs) are a class of smart materials which can recover their shape even after many shape changes in application of an external stimulus. In this paper, flexural behavior of a composite beam, constructed of a corrugated part filled with SMPs, is studied. This composite beam is applicable in sensor and actuator applications. Since the corrugated profiles display higher stiffness-to-mass ratio in the transverse to the corrugation direction, the beams with a corrugated part along the transverse direction are stiffer than ones with a corrugated part along the length. Employing a developed constitutive model for SMPs and the Euler-Bernoulli beam theory, the behavior of the composite beam is studied. Since the utilized constitutive model is in the integral form, the finite-difference-method is used for discretizing the equations. It is shown that load capacity is increased in both composite beams compared to a pure SMP beam. This bigger load capacity is obtained by a low decrease in shape fixity. In addition, for different corrugated shapes (trapezoidal, pseudo-sinusoidal and triangular) with the same SMP content, the beam response is obtained. Finally, the results of the constrained stress-recovery are obtained and the effects of mechanical properties on its behavior, are studied.