Modelling of Damping in Small Satellite Structures Incorporating Bolted Joints

The energy dissipating capability of bolted joints in a small satellite was investigated using Finite Element (FE) analysis. It was found the energy dissipating capability of the bolted joints operating in the microslip region was quite low. The idea of using viscoelastic layer in the bolted joints was introduced to improve the energy dissipation. There are some good constitutive models for viscoelastic materials. However, they cannot be used to model the viscoelastic layer in the satellite because the dimension of the joints and the layers are too small. A spring dashpot joint model was created and extended into the non-linear domain to overcome this problem. Experiments were carried out on different viscoelastic materials. The results were used to determine the properties of spring dashpot systems. Different formulations of stiffness and damping were investigated and optimised to fit the numerical results to the test data. Good correlation was obtained between the models and the data. The spring-dashpot joints were used in a simple satellite model to investigate the effect of joints on the satellite response. This damping design was quite effective in decreasing the response of the satellite structure when it experienced harsh environments like launch