به‌روزرسانی مدل المان محدود سکوی جکتی فراساحلی با استفاده از آنالیز مودال تجربی
نویسنده
دانشکده مهندسی عمران، دانشگاه تبریز
چکیده
امکان تطبیق نتایج حاصل از مدل تجربی سازه‌ها با نتایج حاصل شده از مدل المان محدود متناظر یکی از الزامات مهم در طراحی به‌شمار می‌رود. در این زمینه، با به‌روزرسانی مدل با استفاده از سیگنال‌های اندازه‌گیری شده در آزمایش ارتعاش، می‌توان مدل المان محدود مناسبی را پیشنهاد کرد. از این‌رو، این مقاله با استفاده از تهیه و انجام آزمایش روی مدل قاب فضایی سازه جکتی فراساحلی در مقیاس کوچک در یک آزمایشگاه دینامیک سازه و ارتعاشات، مطالعه‌ای را در مورد روش‌های عددی به‌روزرسانی مستقیم و غیرمستقیم ارائه می‌دهد. همین‌طور در آن با استفاده از آنالیز حساسیت پاسخ سیستم به یک تحریک پایه، رویه انتخاب درجات آزادی غیر‌فعال در مرحله کاهش مدل با یک معیار مناسب مورد ارزیابی قرار می‌گیرد. این عملکرد منجر به همگرایی سریع‌تر الگوریتم تکرار و همچنین حذف مودهای کم اثر می‌شود. از آنجایی که مسأله اصلی در مسائل مرتبط با آنالیز دینامیکی سازه‌ها، پرهزینه و زمان‌بر بودن محاسبات است بنابراین با استفاده از این روش‌ها هم در زمان و هم در هزینه صرفه‌جویی خواهد شد.
کلیدواژه‌ها
عنوان مقاله [English]
Finite Element Model Updating of an Offshore Jacket Platforms using Experimental Modal Analysis
نویسنده [English]
- F. Hosseinlou
An important requirement in design is to be able to compare experimental results from prototype structures with predicted results from a corresponding finite element model. In this context, updating the model using measured vibration test can lead to proposing a desired finite element model. Therefore, this paper presents indirect and direct based numerical updating study of a reduced scale four-story spatial frame structure of offshore jacket platforms constructed and tested at the Structural Dynamics and Vibration Laboratory. Besides, the selection procedure for inactive degrees of freedom in the process of reduced model is evalated, with a reasonable criterion, by using sensitivity analysis of system response under base excitation. This performance leads to faster convergence of iterative algorithm and also, eliminates spurious modes. Since the significant problem fundamental to dynamic structural analysis is the amount of time and cost required for computation, the use of these methods will save both in time and cost.
کلیدواژه‌ها [English]
- Offshore jacket platforms
- optimization
- Numerical updating
- experimental modal analysis
1. Wang, S. H., Li, Y., and Li, H., “Structural Model Updating of an Offshore Platform using the Cross Model Cross Mode Method: An Experimental Study”, Ocean Engineering, Vol. 97, pp. 57-64, 2015.
2. Chen, H. P., and Maung, T. S., “Regularised Finite Element Model Updating using Measured Incomplete Modal Data”, Journal of Sound and Vibration, Vol. 333, pp. 5566-5582, 2014.
3. Fang, S. E., Zhang, Q. H., and Ren, W. X., “An Interval Model Updating Strategy using Interval Response Surface Models”, Mechanical Systems and Signal Processing, Vol. 60, pp. 909-927, 2015.
4. Berman, A., and Nagy, E. J., “Improvement of a Large Analytical Model using Test Data”, AIAA Journal, Vol. 21, No. 8, pp. 1168-1175, 1983.
5. Caesar, B., “Update and Identification of Dynamic Mathematical Models”, 4th IMAC, Los Angeles, California, pp. 394-401, 1986.
6. Denoyer, K. K., and L. D. Peterson, L. D., “Method for Structural Model Update using Dynamically Measured Static Flexibility Matrices”, AIAA Journal, Vol. 35, No. 2, pp. 362-368, 1997.
7. Imregun, M., Visser, W. J.; and Ewins, D. J., “Finite Element Model Updating using Frequency Response Function Data-I: Theory and Initial Investigation”, Mechanical Systems and Signal Processing, Vol. 9, No. 2, pp. 187-202, 1995.
8. Ewins, D. J., Modal Testing: Theory, Practice and Application, Second ed. Research Studies Press Ltd, 2000.
9. Hu, S. L. J., Li, H., and Wang, S. H., “Cross-Model Cross-Mode Method for Model Updating”, Mechanical Systems and Signal Processing, Vol. 21, pp. 1690-1703, 2007.
10. Lin, R. M., Du, H, and Ong, J. H., “Sensitivity Based Method for Structural Dynamic Model Improvement”, Computers & Structures, Vol. 47, No. 3, pp. 349-369, 1983.
11. Lin, R. M., Lim, M. K., and Du, H., “Improved Inverse Eigensensitivity Method for Structural Analytical Model Updating”, Transactions American Society of Mechanical Engineers, Vol. 117, No. 3, pp. 190-199, 1995.
12. Taylan, K., Erdinc, N., Yildiz, H., and Nevzat, O., “A New Method to Determine Dynamically Equivalent Finite Element Models of Aircraft Structures from Modal Test Data”, Mechanical Systems and Signal Processing, Vol. 31, pp. 94-108, 2012.
13. Friswell, M. I., and Mottershead, J. E., Finite Element Model Updating in Structural Dynamics, Kluwer Academic Publishers, Dordrecht, 1995.
14. Esfandiari, A., Bakhtiari-Nejad, F., Sanayei, M., and Rahai, A., “Structural Finite Element Model Updating using Transfer Function Data”, Computers & Structures, Vol. 88, No. 1, pp. 54-64, 2010.
15. Hua, X. G., Chen, Z. Q., and He, X. H., “Monte Carlo Study of the Effect of Measurement Noise in Model Updating with Regularization”, Mechanical Engineering, Vol. 16, No. 94, pp. 182-194, 2012.
16. Sinha, J. K., and Friswell, M. I., “Simplified Models for the Location of Cracks in Beam Structures using Measured Vibration Data”, Journal of Sound and Vibration, Vol. 251, No. 1, pp. 13-38, 2002.
17. Modak, S. V., Kundra, T. K., and Nakra, B. C., “Comparative Study of Model Updating Methods using Simulated Experimental Data”, Computers & Structures, Vol. 80, pp. 437-447, 2002.
18. Jaishi, B., and Ren, W. X., “Damage Detection by Finite Element Model Updating using Modal Flexibility Residual”, Journal of Sound and Vibration, Vol. 290, pp. 369-387, 2006.
19. Jaishi, B., and Ren, W. X., “Finite Element Model Updating Based on Eigenvalue and Strain Energy Residuals using Multiobjective Optimization Technique”, Mechanical Systems and Signal Processing, Vol. 21, No. 1, pp. 2295-2317, 2007.
20. Baruch, M., and Wis, M., “Optimization Procedure to Correct Stiffness and Flexibility Matrices using Vibration Tests”, AIAA Journal, Vol. 16, No. 11, pp. 1200-1210, 1978.
21. Fiswell, M. I., and Mottershead, J. E., “Model Updating in Structural Dynamics: A Survey”, Journal of Sound and Vibration, Vol. 167, No. 2, pp. 347-375, 1993.
22. Miguel, L. F. F., and Menezes, R. C. R., “Model Updating of a Frame Structure using Penalty Functions Based Procedures”, Mecanica Computacional, Vol. 25, pp. 1583-1592, 2006.
23. Fox, R. L., and Kapoor, M. P., “Rate of Change of Eigenvalues and Eigenvectors”, AIAA Journal, Vol. 12, No. 6, pp. 2426-2429, 1968.
24. Wittrick, W. H., “Rates of Change of Eigenvalues, with Reference to Buckling and Vibration Problems”, Journal of the Royal Aeronautical Society, Vol. 66, pp. 590-599, 1962.
25. Guyan, R. J., “Reduction of Stiffness and Mass Matrices”, AIAA Journal, Vol. 3, No. 2, pp. 380, 1965.
26. Hutton, D. V., Fundamentals of Finite Element Analysis, 7th edn. McGraw-Hill, New York, 2004.
27. Fu, Z. H.; and He, J., Modal Analysis, Butterworth-Heinemann, Oxford, 2001.
28. Tshilidzi, M., Finite Element Model Updating Using Computational Intelligence Techniques: Applications to Structural Dynamics, Heidelberg: Springer, 2010.
29. Li, H., Wang, Sh., and Yang, H., “Modal strain energy decomposition method for damage detection of an offshore structure using modal testing information”, Third Chinese German Joint Symposium on Coastal and Ocean Engineering National Cheng Kung University, Tainan, November 8-16, 2006.
2. Chen, H. P., and Maung, T. S., “Regularised Finite Element Model Updating using Measured Incomplete Modal Data”, Journal of Sound and Vibration, Vol. 333, pp. 5566-5582, 2014.
3. Fang, S. E., Zhang, Q. H., and Ren, W. X., “An Interval Model Updating Strategy using Interval Response Surface Models”, Mechanical Systems and Signal Processing, Vol. 60, pp. 909-927, 2015.
4. Berman, A., and Nagy, E. J., “Improvement of a Large Analytical Model using Test Data”, AIAA Journal, Vol. 21, No. 8, pp. 1168-1175, 1983.
5. Caesar, B., “Update and Identification of Dynamic Mathematical Models”, 4th IMAC, Los Angeles, California, pp. 394-401, 1986.
6. Denoyer, K. K., and L. D. Peterson, L. D., “Method for Structural Model Update using Dynamically Measured Static Flexibility Matrices”, AIAA Journal, Vol. 35, No. 2, pp. 362-368, 1997.
7. Imregun, M., Visser, W. J.; and Ewins, D. J., “Finite Element Model Updating using Frequency Response Function Data-I: Theory and Initial Investigation”, Mechanical Systems and Signal Processing, Vol. 9, No. 2, pp. 187-202, 1995.
8. Ewins, D. J., Modal Testing: Theory, Practice and Application, Second ed. Research Studies Press Ltd, 2000.
9. Hu, S. L. J., Li, H., and Wang, S. H., “Cross-Model Cross-Mode Method for Model Updating”, Mechanical Systems and Signal Processing, Vol. 21, pp. 1690-1703, 2007.
10. Lin, R. M., Du, H, and Ong, J. H., “Sensitivity Based Method for Structural Dynamic Model Improvement”, Computers & Structures, Vol. 47, No. 3, pp. 349-369, 1983.
11. Lin, R. M., Lim, M. K., and Du, H., “Improved Inverse Eigensensitivity Method for Structural Analytical Model Updating”, Transactions American Society of Mechanical Engineers, Vol. 117, No. 3, pp. 190-199, 1995.
12. Taylan, K., Erdinc, N., Yildiz, H., and Nevzat, O., “A New Method to Determine Dynamically Equivalent Finite Element Models of Aircraft Structures from Modal Test Data”, Mechanical Systems and Signal Processing, Vol. 31, pp. 94-108, 2012.
13. Friswell, M. I., and Mottershead, J. E., Finite Element Model Updating in Structural Dynamics, Kluwer Academic Publishers, Dordrecht, 1995.
14. Esfandiari, A., Bakhtiari-Nejad, F., Sanayei, M., and Rahai, A., “Structural Finite Element Model Updating using Transfer Function Data”, Computers & Structures, Vol. 88, No. 1, pp. 54-64, 2010.
15. Hua, X. G., Chen, Z. Q., and He, X. H., “Monte Carlo Study of the Effect of Measurement Noise in Model Updating with Regularization”, Mechanical Engineering, Vol. 16, No. 94, pp. 182-194, 2012.
16. Sinha, J. K., and Friswell, M. I., “Simplified Models for the Location of Cracks in Beam Structures using Measured Vibration Data”, Journal of Sound and Vibration, Vol. 251, No. 1, pp. 13-38, 2002.
17. Modak, S. V., Kundra, T. K., and Nakra, B. C., “Comparative Study of Model Updating Methods using Simulated Experimental Data”, Computers & Structures, Vol. 80, pp. 437-447, 2002.
18. Jaishi, B., and Ren, W. X., “Damage Detection by Finite Element Model Updating using Modal Flexibility Residual”, Journal of Sound and Vibration, Vol. 290, pp. 369-387, 2006.
19. Jaishi, B., and Ren, W. X., “Finite Element Model Updating Based on Eigenvalue and Strain Energy Residuals using Multiobjective Optimization Technique”, Mechanical Systems and Signal Processing, Vol. 21, No. 1, pp. 2295-2317, 2007.
20. Baruch, M., and Wis, M., “Optimization Procedure to Correct Stiffness and Flexibility Matrices using Vibration Tests”, AIAA Journal, Vol. 16, No. 11, pp. 1200-1210, 1978.
21. Fiswell, M. I., and Mottershead, J. E., “Model Updating in Structural Dynamics: A Survey”, Journal of Sound and Vibration, Vol. 167, No. 2, pp. 347-375, 1993.
22. Miguel, L. F. F., and Menezes, R. C. R., “Model Updating of a Frame Structure using Penalty Functions Based Procedures”, Mecanica Computacional, Vol. 25, pp. 1583-1592, 2006.
23. Fox, R. L., and Kapoor, M. P., “Rate of Change of Eigenvalues and Eigenvectors”, AIAA Journal, Vol. 12, No. 6, pp. 2426-2429, 1968.
24. Wittrick, W. H., “Rates of Change of Eigenvalues, with Reference to Buckling and Vibration Problems”, Journal of the Royal Aeronautical Society, Vol. 66, pp. 590-599, 1962.
25. Guyan, R. J., “Reduction of Stiffness and Mass Matrices”, AIAA Journal, Vol. 3, No. 2, pp. 380, 1965.
26. Hutton, D. V., Fundamentals of Finite Element Analysis, 7th edn. McGraw-Hill, New York, 2004.
27. Fu, Z. H.; and He, J., Modal Analysis, Butterworth-Heinemann, Oxford, 2001.
28. Tshilidzi, M., Finite Element Model Updating Using Computational Intelligence Techniques: Applications to Structural Dynamics, Heidelberg: Springer, 2010.
29. Li, H., Wang, Sh., and Yang, H., “Modal strain energy decomposition method for damage detection of an offshore structure using modal testing information”, Third Chinese German Joint Symposium on Coastal and Ocean Engineering National Cheng Kung University, Tainan, November 8-16, 2006.
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