<title>Design and preliminary tests of an SMA active composite tab</title>

Abstract

The theory, construction and experimentation of a shape memory alloy composites plate is presented and discussed. The modeling of shape memory effects due to the temperature- induced phase transformation is briefly reviewed. Constitutive relations that relate the stress, strain and temperature of the shape memory alloy are briefly presented. The general tension-bending theory of a composite plate incorporating shape memory alloy wires are derived. Substitution of the shape memory alloy constitutive relations and of the strain compatibility conditions yield a linear system in two variables, the midplane strain, (epsilon) <SUB>0</SUB>, and curvature, (kappa) . However, the coefficients of this linear system are functions of the stress and temperature in the shape memory alloy part of the active composite material. Hence, an iterative process is used to obtain the solution. Construction and experimentation of a 300 mm by 50 mm by 5 mm shape memory active composite plate is described. The composite plate was fabricated from polymeric resin and shape memory wires embedded in the top and bottom surfaces. The experimental set up, instrumentation, test procedure and data collection are presented. Processing of the experimental data, and the resulting displacement-temperature variation are shown and discussed. The shape memory active composite plate was shown to be capable of 35 mm tip displacement when activated.