探空火箭結構之模態分析與驗證

Modal Analysis and Verification of Sounding Rocket Structures

魏丞逸(Wei Cheng-Yi)

指導教授 ： 林章生

國立屏東科技大學/工學院/車輛工程系所/碩士(2021年)

https://doi.org/10.6346/NPUST202100327

摘要

本研究係模態驗證之逆向工程問題分析於重建未知結構有限元素模型的有效性進行探討。吾人利用對國立成功大學航太研究中心所提供之除役探空火箭結構，在無幾何模型檔案、材料參數及明確工作環境資訊情況下重建有限元素模型。吾人將探空火箭進行量測尺寸並繪製幾何模型，查閱相關資訊估測材料參數，使用電腦輔助分析(Computer Aided Engineering, CAE)軟體ANSYS Workbench分別進行模態分析與簡諧響應分析，得到結構幾何模型之模態參數。吾人分別對探空火箭與其構件進行實驗模態分析(Experimental Modal Analysis, EMA)，得到實際結構之頻率響應函數(Frequency Response Function, FRF)並從中獲得模態參數，並與有限元素法(Finite Element Method, FEM)分析之結果相互驗證。為了驗證實驗模態分析識別結果之可靠性，吾人利用實驗模態分析過程所量測的脈衝響應信號，利用亞伯拉罕時域法(Ibrahim Time-Domain Method, ITD)進行模態識別，進而驗證實驗模態分析結果之可靠性，進而修正有限元素模型，以等效於實際結構。

關鍵字

探空火箭 ； 有限元素分析 ； 實驗模態分析 ； 亞伯拉罕時域法 ； 逆向工程問題

並列摘要

The study is focused on inverse engineering problems analysis of the validity of modal verification to reconstruct the finite element (FE) model of sounding rocket structure, supported by Aerospace Science and Technology Research Center of National Cheng Kung University. We measure the size of sounding rocket and recomplete a geometric model. When the relevant information associated with material parameters is available, we use the computer aided engineering (CAE) software ANSYS Workbench to perform modal and harmonic analyses to obtain modal parameters of structural FE model. We perform experimental modal analysis (EMA) on the sounding rocket and its components respectively, and then we obtained frequency response function (FRF) of actual structure and obtained modal parameters itself. Modal analysis results based on finite element Method (FEM) and modal identification results from EMA are mutually verified to confirm the consistency of the FE model and the practical structure. To verify the reliability of EMA identification results, we also performed Ibrahim time-domain method (ITD) using impulse response obtained from EMA. Then, we use the analysis results of EMA to modify FE model to be updated and equivalent to the realistic structure.

並列關鍵字

sounding rocket ； finite element analysis ； experimental modal analysis ； Ibrahim time-domain method ； inverse engineering problems

參考文獻

[1]Akcal, M. U., Yuksek, B. and Ure, K. N., 2017, “Modeling and Simulation of Aerobee-150A Sounding Rocket,” AIAA Modeling and Simulation Technologies Conference.

[2]Allemang, R. J. and Brown, D. L., 1982, “A Correlation Coeifficient for Modal Vector Analysis,” Proceedings of the 1st International Modal Analysis Conferences, pp. 110-116.

[3]Comire, J. and Korde, U. A., 2011, “Laboratory Testing for Sounding Rocket Vibroacoustic Response,” 52nd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference.

[4]Dabrowski, A., Pelzner, K., Krawczuk, S., Goczkowski, J. and Elwertowska, A., 2020, “Preliminary Results from HEDGEHOG REXUS Project – A Sounding Rocket Experiment on Accelerations, Vibration and Heat Flow,” Acta Astronautica, Vol. 177, pp. 80-85.

[5]Fortuna, M., Klepka, A., Dziedziech, K., Staszewski, W. J. and Uhl T., 2016, “Time-Variant Modal Analysis of a CanSat Rocket,” Proceedings of ISMA 2016 Including USD 2016.