关于冲击响应谱

wanyeqing2003

原帖由 hcharlie 于 2010-4-29 20:45 发表
基础是绝对刚体，质量是无穷大。

奥，我看错了。应该是基础运动问题，可以不考虑基础的质量和刚度。

sunspots

呵呵，谢谢楼

ciluya

看了这么多关于冲击响应谱的解释，有了点初步的认识，冲击响应谱其实是针对某个具体的冲击波形，描述其对于一系列单自由度系统的冲击作用，将不同固有频率的单自由度系统在某个特定冲击波形的作用下响应的最大值（加速度）作为纵坐标，固有频率作为横坐标，画出的曲线就是某个冲击波形的SRS，但是对于某个现实中的复杂系统，它在某个冲击波形作用下的冲击响应转换到频域上的曲线这个叫什么呢？肯定不是叫响应谱，这里贴一点英文中对于这个概念的解释
关于冲击响应谱
Response spectrum analysis is an approximate method of computing the peak response of a transient excitation applied to a simple structure or component. This method is used in civil engineering to predict the peak response of a component on a building that is subjected to earthquake excitation; it is also used in aerospace engineering to predict the peak response of equipment in a spacecraft that is subjected to an impulsive load due to stage separation. Because it is an approximate method, response spectrum analysis is often used as a design tool. Response spectrum analysis is also called shock spectrum analysis.
There are two parts to response spectrum analysis: (1) generation of the spectrum and (2) use of the spectrum for dynamic response such as stress analysis. Both are available in NX Nastran.
Figure 11-1 depicts the generation of a response spectrum.


Figure 11-Response Spectrum Generation

Note that the peak response for one oscillator does not necessarily occur at the same time as the peak response for another oscillator. Also note that there is no phase information since only the magnitude of peak response is computed. It is assumed in this process that each oscillator mass is very small relative to the base structural mass so that the oscillator does not influence
the dynamic behavior of the base structure. Once a spectrum is computed, it can be used for the dynamic response analysis of an NX Nastran model of the component. For example, the spectrum generated for a floor in a building that is subjected to an earthquake can then be applied to a complex model of a piece of equipment attached to that floor. The peak response of each mode of the equipment model is obtained from the spectrum, and these peak modal responses are combined to create the overall response.

ciluya

For example, the spectrum generated for a floor in a building that is subjected to an earthquake can then be applied to a complex model of a piece of equipment attached to that floor.The peak response of each mode of the equipment model is obtained from the spectrum, and these peak modal responses are combined to create the overall response。关于这句话不理解，在得到了floor再一个冲击载荷下的SRS以后，怎么用这个来计算equipmnt在其各阶模态下的冲击响应值呢？还有计算以后怎么combine to created the overall response呢？哪位大侠指点一二

kashinhyou

做SRS试验可以参照IEC-60068-2-27 跟IEC-60068-2-57？？
应该是这2个标准我在半年前读过（具体的记得不是太清楚），还有就是MIL-STD-810也是可以做参照哦。
就个人而言：SRS测试做的时候需要一些技术上的判断，没有相应的知识做出来的结果估计会怎么样，比如说要算阻尼等等

yinlei211

hcharlie 发表于 2007-9-1 13:18
　　我再抄一遍书上的冲击谱的定义：
　　冲击谱是单自由度机械系统在规定的瞬态作用下引起的最大响应。它 ...

冲击响应谱应该是描述冲击波的一种方法吧？和冲击波的时域描述、频域描述一样的目的吧？