Principal mode extraction
Challenge: Calculate and analyze a model with high density natural mode efficiently
In the case of analysis for a large size FE model in a higher frequency, it is often found that an analytical investigation of the phenomena by checking natural modes is difficult because the computation time becomes longer since there exist numbers of modes.
In addition, it is not easy to identify the principal mode which is a main factor to generate a peak of FRF because mode contribution ratio is deconcentrated if the mode density is high enough.
How to resolve pains:
When PMA option of ESTECH.NAST+ is applied to the model with high density natural modes, similar natural modes are put together, which contribute to the response significantly and eliminating unnecessary natural modes by singular value decomposition of the deformation pattern in running condition. The above mentioned modes which are putting together and contribute significantly to the response are named principal mode that makes complicated phenomena simpler.
Strength of the Software
- Reduced modal model utilizing principal modes is applicable to speed up variation analysis.
- In the case of complete reproduction of response functions, it is possible to reduce a number of natural modes and simplify the phenomena by using modes which have higher contribution.
- The principal modes depend on excitation condition, response point and frequency range respectively. Therefore, it is available to investigate the mechanism of an individual phenomenon by obtaining principal modes for each phenomenon which is paid attention to.
