LATCH UP SHOCK ESTIMATION FOR DEPLOYMENT MECHANISM

Abstract

The deployable appendages such as solar array/antenna are stowed during launch and deployed in orbit using mechanism. At the end of deployment, the hinges are subjected to shock loads. * In this thesis, the solar array with yoke and n panels are considered for study. The dynamic load induced at the time of locking is assumed to vary linearly along the length of yoke and panels. A mathematical model is developed using the pure bending theory of beam. The root moment as well as moment at interpanel hinges and deflection due to shock load is estimated. The mathematical model has been verified using finite element package, NISA. A sensitivity analysis has also been carried out for establishing the relation between linear static analysis and nonlinear static analysis. It is observed that the variation in root moment between linear and nonlinear analysis is not significant. Finally the non-dimensional parameters are presented taking into account the root moment, moment at interpanel hinges, strain energy and tip deflection. It is observed that the variation of non-dimensional strain energy and non- dimensional tip deflection is parabolic with increase in number of panels. Similar I behaviour is observed in variation in non-dimensional strain energy and non-dimensional moment. The non-dimensional strain energy would help designer in evaluating the moment at the hinges by. directly using the non-dimensional curves. Corresponding to this, two typical examples are presente