Buckling and free vibration analyses of pultruded GFRP laminated composites: Experimental, numerical and analytical investigations

Two of the most important of the loads exposed to the structures whose construction material is pultruded GFRP are buckling and vibration loads. Therefore, it is crucial to determine the behavior of this material against buckling and vibration loads considering the fiber and layer configurations. Pursuant to this goal, comprehensive experimental, numerical and analytical studies have been undertaken. An exact analytical solution based on first order shear deformation plate theory was used for the solution of stability and vibration problems. The virtual displacement principle was utilized herein to derive governing differential equations. Effective material properties of pultruded GFRP composites were obtained by using the mixture rule model. The laminated plate was assumed to be a plate strip in cylindrical bending. The solutions were obtained with an infinite series. On the other hand, a numerical study was conducted by a finite element software, ABAQUS. Burn-out and mechanical tests were performed to determine the mechanical properties of the obtained pultruded GFRP composite specimens. The buckling and modal analysis for natural frequencies tests were utilized to investigate the performance of pultruded GFRP specimens. The experimental findings were compared with the calculated analytical and numerical results, and good conformance was obtained. Macro and micro mechanical damage analyzes were performed to better understand the behavior of the pultruded GFRP composite specimens.