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International Journal of Mechanical and Production Engineering (IJMPE)-IJMPE
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Volume Issue
Volume-7,Issue-1  ( Jan, 2019 )
Paper Title
Investigation of Oblique Impulse in Experimental Modal Analysis via Finite Element Method
Author Name
Lian Yee Cheng, Khoo Shin Yee, Ongzhi Chao, Zubaidah Ismail, Chong Wen Tong, Siamak Noroozi
Department of Mechanical Engineering, University Malaya Malaysia Department of Design and Engineering, Bournemouth University
Modal analysis is the study of dynamic characteristics of a structure, namely the natural frequency, modal damping, and mode shapes. The conventional method is called Experimental Modal Analysis (EMA) with normal impulse technique. The downside of this method is that it requires a long data acquisition time, as the engineer has to perform the impulse in three directions, named axial-, horizontaland vertical- axis of the structure to obtain all dynamic characteristics. Hence, this study proposed a single direction oblique impulse to reduce data acquisition time by 66% for a 3D structure. The objective of this study is to investigate the feasibility of oblique impulse in modal analysis via finite element method (FEM).The proposed method can be investigated comprehensively and much quicker through virtual testing by FEM. The results of the proposed method are being benchmarked to the results of computational modal analysis. It shows that the oblique impulse method is able to determine the desired dynamic characteristics of the structure, which proves that EMA with oblique impulse technique is feasible and has great potential to improve testing time of the conventional normal impulse testing. Keywords - Experimental Modal Analysis, Computational Modal Analysis, Normal Impulse, Oblique impulse, Finite Element Method.
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