I wonder whether Hyperworks or other commercial softwares can compute the modal loss factors of structures with damping directly. If not, how to calculate this parameters based on the output in hyperworks modal analysis. Is complex eigenvalue analysis or frequency response analysis or other analysis need to do to get it.
In HyperWorks, the modal loss factors of a damping structure can be calculated using the Modal Strain Energy (MSE) method. The MSE method is used to extract modal loss factors from the modal analysis results. Here's a general outline of the process:
1. Perform Modal Analysis: First, you need to perform a modal analysis on your damping structure model in HyperWorks. This analysis will provide the natural frequencies, mode shapes, and other modal parameters of the structure.
2. Enable Modal Strain Energy Output: In the modal analysis setup, ensure that the "Modal Strain Energy" output request is enabled. This will instruct the solver to calculate the modal strain energy for each mode.
3. Post-Processing: Once the modal analysis is complete, you can post-process the results using HyperView or another post-processing tool within HyperWorks.
4. Extract Modal Loss Factors: In HyperView, you can use the "Modal Strain Energy" results to extract the modal loss factors for each mode. The modal loss factor is calculated as the ratio of the modal strain energy dissipated by damping to the modal strain energy stored in the structure.
5. Interpret and Use Results: After obtaining the modal loss factors, you can interpret the results to understand the damping behavior of the structure. These loss factors can be used to assess the effectiveness of damping treatments and to optimize the damping design of the structure.
It's important to note that the specific steps for extracting modal loss factors may vary depending on the version of HyperWorks you are using and the exact analysis setup. Therefore, it's recommended to refer to the HyperWorks user manual or consult with technical support for detailed guidance on using the Modal Strain Energy method to calculate modal loss factors for damping structures.
Yishak Asrat Mekonnen Thanks for your help. According to your direction, I have extract element strain energy of metal plate and damping layer separately of each modal. Then I calculate the ratio of sum of element strain energy of damping layer to sum of element strain energy of metal plate. But the result are not the same as the modal loss factor calculated in MATLAB. I wonder whether the sum of element strain energy of damping layer is the modal strain energy dissipated by damping. And the sum of element strain energy of metal plate is the modal strain energy stored in the structure. What's more, I did the normal modal analysis (EIGRL) for the damped structure to extract element strain energy. Because if I choose the complex modal analysis (EIGC), the result cann't output the element strain energy.
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