Discussion Overview
The discussion centers on finding the natural frequency of a system composed of multiple components, specifically an assembly that includes a compressor, condenser, piping, fan, fan bracket, and frame. Participants explore methods for determining the modal response of the overall system and how to relate the modal responses of individual components to that of the total assembly.
Discussion Character
- Exploratory
- Technical explanation
- Debate/contested
Main Points Raised
- One participant seeks an efficient procedure to determine the natural frequency of a complex assembly and requests assistance in correlating the modal responses of individual components with the overall system.
- Another participant suggests using finite element analysis (FEA) software, such as ANSYS or Comsol, to find modal frequencies for assembled components, while also mentioning a less expensive option, LISA, though they express uncertainty about its accuracy.
- A different participant acknowledges the capability of commercial software to calculate natural frequencies but emphasizes the need for a method to relate the individual component frequencies to the total assembly frequency, mentioning mass participation factors for various degrees of freedom.
- One participant recommends searching for "Component mode synthesis" or "Craig Bampton" as a starting point for literature on the topic, indicating that there are many variations and a substantial amount of material available.
Areas of Agreement / Disagreement
Participants express differing views on the methods to relate individual component frequencies to the total assembly frequency. While some suggest using FEA software, others focus on theoretical approaches like component mode synthesis. The discussion remains unresolved regarding the best approach to achieve the desired correlation.
Contextual Notes
Limitations include the potential complexity of the geometry and the need for specific assumptions regarding the relationships between component and assembly frequencies. The discussion does not resolve the mathematical steps required for correlation.