Elastic Constants Identification of Composite wind blade
碩士 === 國立交通大學 === 機械工程系所 === 106 === Composite materials structure fabricated using different manufacturing processes and under different manufacturing environments may have different the material's elastic constants. The purpose of this paper is to identify the elastic constants of composite w...
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| Format: | Others |
| Language: | zh-TW |
| Published: |
2017
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| Online Access: | http://ndltd.ncl.edu.tw/handle/48w3mz |
| Summary: | 碩士 === 國立交通大學 === 機械工程系所 === 106 === Composite materials structure fabricated using different manufacturing processes and under different manufacturing environments may have different the material's elastic constants. The purpose of this paper is to identify the elastic constants of composite wind blades. This study uses the static load test to measure the strain of composite wind blades and dynamic vibration test to investigate the frequency of composite wind blades. The finite element code ANSYS is used to analyze the deformation of the blade. The results have shown that the analysis can simulate the actual situation and the correctness of the blade model is verified.
In this study, a two-stage compound optimization method is used to identify the elastic constants of 2.5 m composite wind blades. The first stage uses the random multi-start and –trajectory method to obtain multi-local minima. The second stage uses the exhaustive search method to find the global minimum. This stage allows the global search in a smaller region to find the global minimum. In the proposed elastic constants identification method, the measured skin surface strains or the natural frequencies of the blade are used to construct the objective function via the least square approach. The identification using the skin surface strains produces the elastic constants with 10% error. The identification using the natural frequencies produces the elastic constants with error 41%. Therefore, the identification method using the measured strains of skin surface can predict the material constants of composite blades more accurately.
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