爆炸荷载作用下弹性与阻尼支承梁的动力响应

为了提高梁的抗爆能力,目前通常是从材料、截面形状等方面考虑．通过在梁端部设置弹性和阻尼支承来提高梁的抗力．为此,应用拉格朗日方程建立了端部弹性与阻尼支承梁的动力方程,通过长作用时间和短作用时间两个爆炸动荷载的典型算例,分析了端部弹性与阻尼支承对梁动态响应的影响,并指出在短作用时间动荷载作用下在梁端部设置弹性与阻尼支承可有效提高梁的抗力．

DYNAMIC RESPONSES OF AN ELASTICALLY SUPPORTED BEAMS WITH DAMPING SUBJECTED TO BLAST LOADS

Much attention has been paid to the properties of materials and the shapes of cross sections of beams in order to increase the resistance of blast-loaded structures. This paper discusses how to increase the blast resistance of beams effectively by elastic and damping supports at the ends of beams. The equations of the forced vibration of an elastically supported beam with damping are obtained by the Lagrange equations. The responses of the beam subjected to two typical blast loads with long and short durations are analyzed. The numerical results show that the displacements of the ends are decreased with the increase of the damping coefficient and the stiffness of the elastic support. In the case of blast loads with long duration, the resistance of beams can only be increased effectively by using elastic and damping supports simultaneously at the ends of beams, while the resistance of beams can be increased effectively by using elastic and damping supports either jointly or separately in the case of blast loads with short duration.