Priyadarshi Das

A combined experimental and numerical buckling analysis is performed for Carbon nanotube-reinforced composite (CNTRC) laminates under uniaxial in-plane compressive load. A finite element simulation program is developed in MATLAB environment and the recorded buckling responses are verified with the experimental results. Closely aligned numerical and experimental results exhibits that inclusion of 0.3% CNT increases buckling strengths of CNTRC composite laminates, regardless of their geometrical parameters. Clamped edge laminates exhibit higher buckling mode shapes, influenced by aspect ratio and edge restraint. Microscopic analysis of CNTRC's fractured surface under compression shows enhanced buckling strength attributed to CNTs’ bridging and pullout effects in the matrix, suppressing crack initiation and propagation. Field Emission Scanning Electronic Microscope (FESEM) is utilized for this investigation.

Cracks in structural elements can significantly affect their dynamic behaviour and lead to detrimental consequences. This study investigates the influence of cracks on the natural frequency of a laminated beam under free vibration, employing a combination of finite element method (FEM) analysis and experimental work. The numerical computation is done using ABAQUS simulation software by developing a comprehensive FEM model that accurately represents the laminated beam's mechanical behaviour, considering material anisotropy, geometry and crack propagation. The finite element model is validated through experimental tests conducted on both intact and cracked laminated beam specimens. The experimental setup utilizes Fast Fourier Transform (FFT) analyzer high-precision measurement tool to obtain accurate natural frequency values. The parametric study is conducted to analyze the impact of crack location, size, and orientation on the laminated beam's natural frequency. The FEM simulations reveal that the presence of cracks leads to a reduction in natural frequency, indicating a decrease in structural stiffness. The extent of frequency reduction is found to be influenced by crack characteristics and their proximity to critical locations within the beam. The experimental investigations corroborate the FEM findings, highlighting the consistency between numerical predictions and actual measurements.