Performance investigation of variable damping shock absorber combined with conventional semi-active vibration control logics

The shock induced by a rocket lift-off and pyrotechnic device actuation for interstage separation can cause damage to the on-board instruments of a spacecraft when the acceleration generated by the input shock exceeds their allowable acceleration value. The shock can be attenuated by mounting a shock absorber. In this paper, we propose a variable damping shock attenuation strategy combined with conventional semi-active vibration control laws derived from a two elements model composed of variable damping and spring stiffness that would attenuate the shock such that the main instrument's input acceleration does not exceed the allowable acceleration value. The analysis results indicate that the combination of shock and conventional semi-active control logic attenuates the shock level better than an optimal passive and conventional semi-active control system. The strategy is also effective for suppressing the consequent vibration induced by the shock event. (c) 2013 Elsevier Masson SAS. All rights reserved.