考虑谱跌的舰载设备冲击响应谱分析法

A spectrum method for shock response evaluation of shipboard machinery considering spectrum dip effect

在舰载机械设备的水下非接触爆炸冲击响应评估和抗冲击设计中,由给定的基础输入运动直接计算,如Duhamel积分,得出的响应谱不能作为谱分析计算输入谱,实际输入谱必须考虑"谱跌"的影响。文中结合一多自由度系统的冲击响应谱分析计算,解释了"谱跌"产生的原理,给出了"谱跌"谱的具体建立方法;运用DDAM对一推进轴系进行了冲击响应计算,得出了各轴承支撑处的最大变形,并提出了考虑推进轴转速条件下的响应谱分析方法;为检验舰载设备的抗冲能力和抗冲设计提供一种途径。

For a given base shock excitation in time domain, its shock spectrum calculated by direct integration such as Duhamel integration can not be accepted as the input spectrum when conducting a shock response spectrum analysis for some equipments and structures under that given base shock excitation. This often occurs in the UNDEX responses evaluation and anti-shock design for large-scale shipboard machinery. The fact is that the actual input spectrum should incorporate the ＇spectrum dip＇ effect. In this paper, take the shock response spectrum analysis of a muhi-dof system as for example, the principle of ＇spectrum dip＇ effect was explained, and how to build ＇spectrum dip＇ spectrum was answered. A shock response analysis of a propulsion shaft was conducted by DDAM, and the maximum deformations in positions of bearing sup- ports are obtained. Finally, a method was proposed to conduct shock response calculation for propulsion shaft considering the shaft＇s rotating velocity.