Experimental and Numerical Investigation of the Natural Frequency for the Intact and Cracked Laminated Composite Beam

ABSTRACT

In this study, several composite beam samples were made from woven fiberglass and epoxy. The first sample was created using epoxy, whereas the others used epoxy together with fiberglass layers. These samples were used to study, experimentally and numerically, the effect of fiberglass layers on the natural frequency of composite beams. A numerical model was constructed using ANSYS software 17.2 to assess vibration properties for the manufactured samples. The effects of boundary conditions (simply supported, clamped-clamped, and clamped-free), with crack depths (2 mm and 3 mm) and the number of fiberglass layers (0, 1, 2, 3, and 4) were investigated. The results of the experimental and numerical models were compared, and the numerical model was acceptable with an error rate of less than 15%. Crack depth has a significant impact on natural frequency and mode shape; therefore, transverse cracks were created in the upper surfaces of beams to investigate the vibration mode shape and natural frequency.

Keywords
Frequency; Cracked composite beam; Fiberglass; Epoxy; Free vibration; Mode shape