Visco-Elasto-Plastic Behavior of Creased Space Membrane

This paper addresses the ways by which the releasing and deploying behaviors of a creased space membrane can be predicted accurately. Although existing studies have analyzed the released shape of a creased membrane by considering the elasto-plastic properties, the shape did not agree with the experimental results when the membrane was tightly creased. To examine the released shape of the membrane, creasing and releasing experiments are first conducted. The experimental results indicate that the opening angle of the crease increases with increasing elapsed time after the release due to stress relaxation. The stress relaxation behavior is predicted using finite element analysis (FEA) by considering the visco-elasto-plastic material properties. In addition, an analytical model of the releasing and deploying membrane has been proposed here. The results of the FEA and the analytical model indicate that the released angles are in good agreement with those in the experimental results. Thus, the effects of viscosity are considered important for predicting the releasing behavior of the space membrane.