The sensitivity analysis of a geometrically unstable structure under various pulse loading

The dynamic response of a structure depends on both the structure and the applied load. A pulse approximation method proposed by Youngdahl has been proved to be applicable to stable structures and it has been adopted to deal with arbitrary loading pulse in analyses. However, for the structures possessing unstable loadedisplacement properties, the applicability of pulse approximation method needs to be validated. In our previous theoretical study, by employing the rigid-perfectly plastic idealization, the static and dynamic responses of tensor skin are obtained, revealing its softening (i.e. geometrically unstable) behavior. In the present paper, a similar theoretical approach is employed together with the pulse approximation method to examine the effect of various pulse shapes on the final deflection of the tensor skin. It is found that the final deflections are insensitive to pulse shape, and the differences resulted from different pulses are less than 10%. Hence, the pulse approximation method is also applicable to geometrically unstable structures such as tensor skin. Besides, for various pulse shapes, it is found that the final deflection of tensor skin increases with the total impulse as well as the effective pressure. To achieve a specified deflection, it only requires smaller total impulse for a more intensive impact loading. Furthermore, a damage diagram of tensor skin is constructed in terms of the failure impulse and the effective pressure under different pulse loading. By comparing various pulses with the same impulse level and effective pressure, the explosive pulse is more dangerous than other pulse shapes in producing failure of tensor skin. 2014 Elsevier Ltd. All rights reserved.