Membrane wrinkling patterns and control with SMA and SMPC actuators

Abstract

Wrinkling is a main factor affecting the performance of the membrane structures and is always considered to be a failure as it can cause dramatic decrease of shape accuracy. The study of membrane wrinkling control has the analytical and experimental meanings. In this paper, a feasible membrane shape control method is presented. An expression of wrinkle wavelength using stress extremum principle is established based on the tension field theory and the Von Karman large deflection formula which verifies the generation and evolution reason of membrane wrinkles. The control mechanism for membrane wrinkles is developed using shape memory alloy (SMA) and shape memory polymer composite (SMPC) actuators which are attached to the boundaries of the membrane for producing contraction/expansion forces to adjust the shape of the membrane. The whole control process is monitored by photogrammetric technique. Numerical simulations are also conducted using ANSYS finite element software with the nonlinear post-buckling analytical method. Both the experimental and numerical results show that the amplitudes of wrinkles are effectively controlled by SMA and SMPC actuators. The method introduced in this paper provides the foundation for shape control of the membrane wrinkling and is important to the future work on vibration control of space membrane structures.