© 2012 Putti Srinivasa Rao, Ch.Ratnam. This is a research/review paper, distributed under the terms of the Creative Commons Attribution-Noncommercial 3.0 Unported License http://creativecommons.org/licenses/by-nc/3.0/), permitting all non commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Experimental and Analytical Modal Analysis of Welded Structure Used For Vibration Based Damage Identification By Putti Srinivasa Rao, Ch.Ratnam Andhra University, Visakhapatnam, Andhra Pradesh, India Abstract - This paper presents a systematic procedure and details of the use of experimental and analytical modal analysis of a welded structure used for vibration based damage identification. First an experimental modal analysis was conducted on the undamaged welded structure model used for vibration based damage identification. Using impact hammer test, when the test structure is fitted to the multi-axis electro dynamic vibration shaker .In this experimental modal analysis frequency response functions are calculated from measured input force and output response of a structure using piezoelectric accelerometers from the frequency response function the peaks were identified. To compare the experimental modal analysis values finite element modal analysis was conducted using ANSYS software version 11.0. It has been observed from the results the natural frequencies obtained from the experimental modal analysis and ANSYS software version 11.0 shows a good consistency in comparison. Keywords : Experimental Modal Analysis, Theoretical Modal Analysis, Finite Element Method, Impact Hammer, Vibration Based damage identification, Eigenvalues and Eigenvectors, frequency response function, Resonance condition. GJRE-A Classification : FOR Code: 091304 ExperimentalandAnalyticalModalAnalysisofWeldedStructureUsedForVibrationBasedDamageIdentification Strictly as per the compliance and regulations of: Global Journal of researches in engineering Mechanical and mechanics engineering Volume 12 Issue 1 Version 1.0 January 2012 Type: Double Blind Peer Reviewed International Research Journal Publisher: Global Journals Inc. (USA) Online ISSN: 2249-4596 Print ISSN:0975-5861