Abstract
In the present research, a crane frame has been investigated by using finite element method. The damage is simulated by reducing the stiffness of assumed elements with ratios (10% and 20 %) in mid- span of the vertical column in crane frame. The cracked beam with a one-edge and non-propagating crack has been used. Six cases of damage are modeled for crane frame and by introducing cracked elements at different locations with ratio of depth of crack to the height of the beam (a/h) 0.1, 0.20. A FEM program coded in Matlab 6.5 was used to model the numerical simulation of the damage scenarios. The results showed a decreasing in the five natural frequencies from undamaged beam which means the indication of presence of the damage. The direct comparison gives an indication of the damage but the location of the damage, is not detected. The method based on changes in the dynamics characteristics of the beam structures are examined and evaluated for damage scenarios. The results of the analysis indicate that the residual error method performs well in detecting, locating and quantifying damage in single and multiple damage scenarios.
References
[2] Black, P., (1966). “Strength of materials” /first edition.
[3] Dewen, B. E, M.E. (2004). “Damage detection in mechanical structures through coupled response measurements”. A thesis submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Mechanical Engineering /University of Queensland, Brisbane, Australia.
[4] Herrera, J. C., (2005). “Evaluation of structural damage identification methods based on dynamic characteristics”. A thesis submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in civil engineering / University of Puerto Rico.
[5] Dinkler, (2004). “Damage detection in structures using a parameter identification method ”. 2nd European Workshop on Structural Health Monitoring. July 7-9, 2004, Amazeum Conference Centre at Deutsches MuseumMunich, Germany.
[6] Barasiliano A., Doz G.N. and Brito J.L., (2003). “Damage identification in continuous beams and frame structures using the Residual Error method in the movement equation”. Nuclear Engineering and Design 227, 1-17.
[7] Qian, G.L. and Jiang, J.S., (1990) “The dynamic behavior and crack detection of a beam with a crack”. Journal of sound and vibration, Vol.138, No. 2, 233-243.
[8] Kisa, M. and Brandon, J., (2000). “The effect of cracks on the dynamics of a cracked cantilever beam”. Available online at http:// www.idealibrary.com on IDEAL, Cardiff, England. Academic press.
[9] Singor L., F., (1951). “Strength of materials”. Second edition (book).
[10] Merovitch L., (1975). “Elements of vibrations analysis”, (Book) International student edition.
[11] Hellan, K., (1984). “Introduction to fracture mechanics”, (Book). University of Trondheim /Norway. Printed in USA
Copyright: Open Access authors retain the copyrights of their papers, and all open access articles are distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution and reproduction in any medium, provided that the original work is properly cited. The use of general descriptive names, trade names, trademarks, and so forth in this publication, even if not specifically identified, does not imply that these names are not protected by the relevant laws and regulations. While the advice and information in this journal are believed to be true and accurate on the date of its going to press, neither the authors, the editors, nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein.