All Title Author
Keywords Abstract


A New Flexibility Based Damage Index for Damage Detection of Truss Structures

DOI: 10.1155/2014/460692

Full-Text   Cite this paper   Add to My Lib

Abstract:

A new damage index, called strain change based on flexibility index (SCBFI), is introduced to locate damaged elements of truss systems. The principle of SCBFI is based on considering strain changes in structural elements, between undamaged and damaged states. The strain of an element is evaluated using the columnar coefficients of the flexibility matrix estimated via modal analysis information. Two illustrative test examples are considered to assess the performance of the proposed method. Numerical results indicate that the method can provide a reliable tool to accurately identify the multiple-structural damage for truss structures. 1. Introduction Structural damage detection has a great importance in civil engineering. Neglecting the local damage may cause the reduction of the functional age of a structural system or even an overall failure of the structure. Therefore, damage detection is an important issue in structural engineering. The basis of many damage identification procedures is observing the changes in structural responses. Damage reduces structure’s stiffness and mass, which leads to a change in the static and dynamic responses of the structure. Therefore, the damage detection techniques are generally classified into two main categories. They include the dynamic and static identification methods requiring the dynamic and static test data, respectively. Because of the global nature of the dynamic responses of a structure, techniques for detecting damage based on vibration characteristics of structures have been gaining importance. Presence of a crack or localized damage in a structure reduces its stiffness leading to the decrease of the natural frequencies and the change of vibration modes of the structure [1–3]. Many researchers have used one or more of these characteristics to detect and locate the structural damage. Cawley and Adams [4] used the changes in the natural frequencies together with a finite element model to locate the damage site. Although it is fairly easy to detect the presence of damage in a structure from changes in the natural frequencies, it is difficult to determine the location of damage. This is because damage at two different locations associated with a certain amount of damage may produce the same amount of frequency change. Furthermore, in the case of symmetric structures, the changes in the natural frequencies due to damage at two symmetric locations are exactly the same. There is thus a need for a more comprehensive method of damage assessment in structures. To overcome this drawback, mode shapes have been used for

References

[1]  R. D. Adams, P. Cawley, C. J. Pye, and B. J. Stone, “A vibration technique for non-destructively assessing the integrity of structures,” Journal of Mechanical Engineering Science, vol. 20, no. 2, pp. 93–100, 1978.
[2]  P. Gudmundson, “The dynamic behaviour of slender structures with cross-sectional cracks,” Journal of the Mechanics and Physics of Solids, vol. 31, no. 4, pp. 329–345, 1983.
[3]  T. K. Obrien, “Stiffness change as a non-destructive damage measurement,” in Mechanics of Non-Destructive TestIng, W. W. Stinchcomb, Ed., pp. 101–121, Plenum Press, New York, NY, USA, 1980.
[4]  P. Cawley and R. D. Adams, “The location of defects in structures from measurements of natural frequencies,” The Journal of Strain Analysis for Engineering Design, vol. 14, no. 2, pp. 49–57, 1979.
[5]  A. K. Pandey, M. Biswas, and M. M. Samman, “Damage detection from changes in curvature mode shapes,” Journal of Sound and Vibration, vol. 145, no. 2, pp. 321–332, 1991.
[6]  J.-T. Kim, Y.-S. Ryu, H.-M. Cho, and N. Stubbs, “Damage identification in beam-type structures: frequency-based method vs mode-shape-based method,” Engineering Structures, vol. 25, no. 1, pp. 57–67, 2003.
[7]  M. A. Mannan and M. H. Richardson, “Detection and location of structural cracks using FRF measurements,” in Proceedings of the 8th International Modal Analysis Conference (IMAC '90), pp. 652–657, 1990.
[8]  A. K. Pandey and M. Biswas, “Damage detection in structures using changes in flexibility,” Journal of Sound and Vibration, vol. 169, no. 1, pp. 3–17, 1994.
[9]  M. Raghavendrachar and A. Aktan, “Flexibility by multireference impact testing for bridge diagnostics,” Journal of Structural Engineering, vol. 118, no. 8, pp. 2186–2203, 1992.
[10]  A. Tomaszewska, “Influence of statistical errors on damage detection based on structural flexibility and mode shape curvature,” Computers and Structures, vol. 88, no. 3-4, pp. 154–164, 2010.
[11]  J. Li, B. Wu, Q. C. Zeng, and C. W. Lim, “A generalized flexibility matrix based approach for structural damage detection,” Journal of Sound and Vibration, vol. 329, no. 22, pp. 4583–4587, 2010.
[12]  Q. W. Yang and B. X. Sun, “Structural damage identification based on best achievable flexibility change,” Applied Mathematical Modelling, vol. 35, no. 10, pp. 5217–5224, 2011.
[13]  Q. W. Yang, “A new damage identification method based on structural flexibility disassembly,” JVC/Journal of Vibration and Control, vol. 17, no. 7, pp. 1000–1008, 2011.
[14]  J. Zhang, P. J. Li, and Z. S. Wu, “A new flexibility-based damage index for structural damage detection,” Smart Materials and Structures, vol. 22, pp. 25–37, 2013.
[15]  M. Nobahari and S. M. Seyedpoor, “An efficient method for structural damage localization based on the concepts of flexibility matrix and strain energy of a structure,” Structural Engineering and Mechanics, vol. 46, no. 2, pp. 231–244, 2013.
[16]  J.-M. Ndambi, J. Vantomme, and K. Harri, “Damage assessment in reinforced concrete beams using eigenfrequencies and mode shape derivatives,” Engineering Structures, vol. 24, no. 4, pp. 501–515, 2002.
[17]  A. Alvandi and C. Cremona, “Assessment of vibration-based damage identification techniques,” Journal of Sound and Vibration, vol. 292, no. 1-2, pp. 179–202, 2006.
[18]  H. W. Shih, D. P. Thambiratnam, and T. H. T. Chan, “Vibration based structural damage detection in flexural members using multi-criteria approach,” Journal of Sound and Vibration, vol. 323, no. 3-5, pp. 645–661, 2009.
[19]  S. M. Seyedpoor, “A two stage method for structural damage detection using a modal strain energy based index and particle swarm optimization,” International Journal of Non-Linear Mechanics, vol. 47, no. 1, pp. 1–8, 2012.
[20]  M. Paz and W. Leigh, Structural Dynamics: Theory and Computation, Springer, 5th edition, 2006.
[21]  R. D. Cook, D. S. Malkus, and M. E. Plesha, Concepts and Application of Finite Element Analysisedition, Wiley, New York, NY, USA, 3rd edition, 1989.
[22]  D. L. Logan, A First Course in the Finite Element Method, Cengage Learning, 5th edition, 2012.
[23]  M. Nobahari and S. M. Seyedpoor, “Structural damage detection using an efficient correlation-based index and a modified genetic algorithm,” Mathematical and Computer Modelling, vol. 53, no. 9-10, pp. 1798–1809, 2011.
[24]  M. R. N. Shirazi, H. Mollamahmoudi, and S. M. Seyedpoor, “Structural damage identification using an adaptive multi-stage optimization method based on a modified particle swarm algorithm,” Journal of Optimization Theory and Applications, 2013.

Full-Text

comments powered by Disqus

Contact Us

service@oalib.com

QQ:3279437679

微信:OALib Journal