本帖最后由 mxlzhenzhu 于 2012-8-24 11:29 编辑
这是我在Nastran开内部会议的时候的文献中找到的说法:
Modal participation factors, by their nature, are useful only in the low-frequency range where the resonance frequencies are well separated, and the response is dominated by a small number of modes. On the contrary, geometric participation factors are useful also at higher frequencies where the response has contributions from a large number of modes. There are two types of geometric participation factors, namely panel participation factors and grid participation factors.
Participation factors are complex quantities, summing up to the complex response. Thus, if they are divided by the response, they sum up to one. The participation factors divided by the response are called normalized participation factors.
Normalized participation factors are complex quantities, too. The real parts of the normalized participation factors sum up to one whereas the imaginary parts sum up to zero. Thus, the real part of a normalized participation factor is that part of the participation factor that is in phase with the total response, divided by the magnitude of the total response. It is called the modal fraction. The phase of a normalized participation factor is the phase of the participation factor relative to the total response.
MER-MREMER-MR-EFMASS An important diagnostic tool is the elastic-rigid coupling matrix(MER), a triple product of the elastic mode shape matrix, the ASET Mass Matrix, and the rigid body displacement matrix with respect to the interface. This N×6 matrix gives the square root of the effective mass in each retained mode so that the product of each element of this matrix with itself gives the effective mass contained in that mode in the associated direction. These values are in EFMASS. This matrix can be used to determine which modes are energetic in terms of interface loading. Table 22 shows a sample MER matrix taken from Reference 3. The elements of this matrix have been squared and units converted to give recognizable weight units.
更多关于模态有效质量的讨论======这篇文章已经终结了所有知识点了。
再来一个SCI文献:
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