Numerical Synthesis of Bending Behaviour of Flexible Composite Tape Spring

Abstract

The tape spring is defined as a straight, thin-walled elastic strip with a curved cross section. It has inherent properties which allow for folding elastically, and when unfolded, it releases stored energy. In aerospace applications, these properties are used to deploy an antenna, solar panels, structural booms, and arrays. For many years, metallic tape springs have been in application, but the present trend is towards a tape spring made of carbon fibre-reinforced plastic (CFRP) due to its low mass, low coefficient of thermal expansion, and tailorable properties. The tape springs made of CFRP have wide applications for space deployable structures. This work comprises the exploration of numerical methods to find the moment-rotation relation of folding the CFRP tape spring. The moment-rotation relation is obtained for equal and opposite sense bending using numerical methods like the analytical approach and the finite element (FE) method. Detailed nonlinear structures simulations are carried out using the nonlinear explicit dynamic solver Altair Radioss. Material properties [0°, 90°]2 lay-up style for laminates and boundary conditions are applied to the CFRP tape spring to analyse the effect of a moment with angular rotation. Conclusions were made with the results obtained by FE simulations in comparison with the results obtained by an analytical model. The FE simulation results deviate from the analytical model with a maximum bending moment for equal sense by 5.84% and the opposite sense bending by 1.01%. The results are in good agreement and presented with logical conclusions.