Abstract: Composite beams are increasingly used in aerospace, automobile and other applications. Crack is the most common defect in structures during its service life. The cracked composite beams are subjected to dynamic loads and the vibration of the cracked beams is of technical significance to the structural integrity of systems. The objective of the present investigation is to demonstrate the vibration characteristics of laminated composite beams (LCB) with multiple transverse cracks. Finite element method (FEM) is used for the frequency-based crack analysis in this study. A computer program is developed in MATLAB environment for numerical analysis. First-order shear deformation theory (FSDT) is adopted for the numerical analysis. Composite specimens are casted using hand lay-up technique and are tested for its material constants under tensile test. Experiments are conducted using woven roving. Glass/Epoxy laminated beam samples with pre-defined cracks. The obtained test results from the experimental work using FFT analyzer are validated with the numerical results obtained through MATLAB. The effects of natural frequencies with respect to the various boundary conditions, crack depth and locations are investigated to support in real applications. A fine agreement is accomplished between the numerical and test results. Both the studies showed that natural frequencies in the LCB are significantly influenced by the location and size of the cracks. The results show that natural frequencies are decreased with cracks and an increase in
fiber orientations of composite cracked beams.

Keywords: Laminated composite beam, Vibration, Cracks, Finite element method, FFT analyser.

Biography: Prof. Shishir Kumar Sahu is currently working as Professor (Higher Administrative Grade) in Civil Engineering, National Institute of Technology, Rourkela, India. He has served as Head of Department of Civil Engineering, Dean, Planning and Development and Head, Planning and Architecture and Chairman, Board of Trustee of the institute. His teaching interests include Structural analysis, Finite element method, Analysis and design of plates and shells. He received his Ph. D. from IIT, Kharagpur and did his postdoctoral research at ISVR, Southampton University, UK through the Indo-British UKIERI fellowship. He has supervised 09 Ph. Ds. and supervising 03 scholars now. He is the author of more than 100 publications including 60 peer-reviewed international journals with SCI/SCOPUS indexing with total citation of 825 and an h-index of 16. He has written 4 book chapters on Composite structures’. He has visited Germany, United Kingdom, Singapore, Hong Kong, Indonesia etc. His main research interests includes Structural mechanics, FEM, dynamics, stability, Fracture Mechanics, Plates and shell structures including composites.