Transactions of the Korean Society of Mechanical Engineers A (대한기계학회논문집A)

The Korean Society of Mechanical Engineers (대한기계학회)
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Structural Optimization under Equivalent Static Loads Transformed from Dynamic Loads Based on Displacement

변위에 기초한 동하중에서 변환된 등가정하중하에서의 구조최적설계

  • Published : 2000.08.01
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Abstract

All the loads in the real world act dynamically on structures. Since dynamic loads are extremely difficult to handle in analysis and design, static loads are utilized with dynamic factors. The dyna mic factors are generally determined based on experiences. Therefore, the static loads can cause problems in precise analysis and design. An analytical method based on modal analysis has been proposed for the transformation of dynamic loads into equivalent static load sets. Equivalent static load sets are calculated to generate an identical displacement field in a structure with that from dynamic loads at a certain time. The process is derived and evaluated mathematically. The method is verified through numerical tests. Various characteristics are identified to match the dynamic and the static behaviors. For example, the opposite direction of a dynamic load should be considered due to the vibration response. A dynamic bad is transformed to multiple equivalent static loads according to the number of the critical times. The places of the equivalent static load can be different from those of the dynamic load. An optimization method is defined to use the equivalent static loads. The developed optimization process has the same effect as the dynamic optimization which uses the dynamic loads directly. Standard examples are solved and the results are discussed

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References

  1. Schmit, L. A., 1960, 'Structural Design by systematic Synthesis,' Proceedings of the 2nd Conference on Electric Computation, ASCE, New York
  2. Feng, T.T., Arora, J.S., and Haug, E.J., 1977, 'Optimal Structural Design under Dynamic Loads,' Int. J. for Num. Mech. in Eng., Vol. 11, pp. 39-62 https://doi.org/10.1002/nme.1620110106
  3. Haug, E.J., Arora, J.S., and Feng, T.T., 1978, 'Sensitivity Analysis and Optimization of Structures for Dynamic Response,' J. of Mech. design, Vol. 100, pp. 311-318
  4. Hsieh, C.C. and Arora, J.S., 1984, 'Design Sensitivity Analysis and Optimization of Dynamic Response,' Comput. Meths. Appl. Mech. Engrg. Vol. 43, No. 2, pp. 195-219 https://doi.org/10.1016/0045-7825(84)90005-7
  5. Lim, O.K. and Arora, J.S., 1987, 'Dynamic Response Optimization Using An Active Set RQP Algorithm,' Int. J. for Num. Mech. in Eng., Vol. 24, pp. 1827-1840 https://doi.org/10.1002/nme.1620241002
  6. Haftka R.T. and Gurdal Z., 1991, Elements of Structural Optimization, Kluwer Academic Publishers, The Netherlands
  7. 최우석, 강신천, 신민재, 박경진, 1996, '자주포 로드암 동하중의 상당 정하중으로의 변환 및 형상최적설계,' 대한기계학회논문집(A), 제20권, 제12호, pp. 3767-3781
  8. Shin, M.J., Choi, W.S., and Park, G.J., 1997, 'Transformation of a Dynamic Load into an Equivalent Static load and Shape Optimization of the Road Arm,' PACAM V Conference, Puerto Rico
  9. Choi, W.S. and Park, G.J., 1999, 'Transformation of Dynamic Loads into Equivalent Static Loads Based on Modal Analysis,' Int. J. for Num. Meth. in Engng., Vol. 46, pp. 29-43 https://doi.org/10.1002/(SICI)1097-0207(19990910)46:1<29::AID-NME661>3.0.CO;2-D
  10. Kang, B.S., Choi, W.S., and Park, G.J., 1999, 'Structural Optimization Under Equivalent Static Loads Transformed form Dynamic Loads Based on Displacement,' AIAA Conference, St. Louis, MO.
  11. Grandhi, R.V., Haftka, R.T., and Watson, L.T., 1986, 'Design-Oriented Identification of Critical Times in Transient Response,' AIAA Journal, Vol. 24, No. 4, pp. 649-656
  12. GENESIS User Manual: version 3.0, 1996, VMA Engineering
  13. Arora, J.S. and Tseng, C.H., 1987, User's Manual for IDESIGN : version 3.5 Optimal Design Laboratory, College of Engineering, The University of Iowa, Iowa City, U.S.A.
  14. CSA/NASTRAN User's Manual, 1994, CSAR.