Experimental and numerical study on free vibration of cracked woven fiber glass/epoxy composite beam

Abstract

Composite beams are generally utilized in machinery structures with high-speed velocity, aircraft, and lightweight structures because of their high stiffness-to-weight proportions, a high degree of resistance to corrosion, tailor ability, and fatigue. Crack is one of the most critical damages in composite material as it greatly reduces the stiffness and strength of the member. These damages are a prime cause of increasing the vibration amplitude that leads to catastrophic failures. Structures are frequently exposed to dynamic loads during their administration life. So the assessment of the dynamic properties of cracked composite beams is of considerable technical importance and in this way, the subject of the present investigation. In the present study, changes in natural frequencies of industry-driven woven fiber Glass/Epoxy composite bar with transverse cracks are recorded numerically and experimentally. Finite element method (FEM) is utilized to explore the free vibration of the cracked composite beam. The FE model is created utilizing an eight-noded two-dimensional quadratic isoparametric component with 3 degrees of freedom for each node. The numerical analysis is done through the solution of the beam equations for the Eigenvalues accounting for shear deformation. FE software ANSYS is employed for simulation of free vibration. The experimental tests are done by utilizing a hammer test and the frequency response function (FRF) is shown on FFT analyzer. The numerical outcomes acquired utilizing ANSYS are approved with the trial results. The impacts of fiber orientation, crack depth and positions on the frequencies are investigated about its support in applied fields. The recorded test and numerical results agreed on the significant effects of crack location and depth on the natural frequencies of the laminated beam. The results show that the increase in fiber orientation considerably reduces the natural frequencies of the laminated composite beam.