Effect of thickness on the shape memory properties of bisphenol a epdxy based shape memory polymer composites

Shape memory polymer (SMP) is one of the most highly researched branches of polymer materials in the recent past. It is often called as a smart material due to its unique capability to memorize original shape. Up to now, shape memory polymer composites (SMPCs) are widely being used for developing light weight and low thickness components for space missions. Increasing thickness and fibre layers will improve mechanical properties, but can adversely affect shape memory effect (SME) and increase the possibility of delamination when programming. To study this phenomenon, a 3x3 Taguchi array for material thicknesses of 3, 4 and 5 mm was developed. Carbon, glass and basalt fibres were used to reinforce SMPs in various mass fractions. Shape programming was carried out at the onset of storage modulus (Ts) and peak of Tan (delta) (T-delta). SME was analysed in terms offixity ratio (Rf), recovery ratio (Rr) and areal damage percentage (ADP) due to programming. Samples deformed at T-delta showed high ADP (> 16%) while at T-s minimal ADP was 0.7 %. Moreover, addition of a unidirectional fibre layer in the compressing side of the specimen (with fibres parallel to the width) has minimized local fibre buckling when programming.