Computational and experimental strain analysis of flexural bending of thick glass/epoxy laminates

This paper introduces a numerical model to predict strain in a thick glass/epoxy laminates subjected to flexural bending moment and bolt joint loads. The accuracy of the proposed model was verified by experimental tests using strain gages and Digital Image Correlation (DIC) methods. Higher specific strength and stiffness of composite materials make them an appropriate substitute for aluminum and steel in the aerospace industry. The yoke of the helicopter is one of the recent applications of thick composite structures. The yoke connects the main rotor blade to the hub using bolt joints and it is manufactured as a thick glass/epoxy beam. Performing the experimental tests during the design process of the yoke is highly expensive and time-consuming. In this study, a finite element model was developed to predict the structural behavior of the yoke in the presence of flexural bending which is the main load in the real application. This model can be utilized in the design process of the yoke to reduce the number of the required iterative experiments. The results showed the agreement between strain distribution obtained from the finite element model and the experimental results from strain gages and Digital Image Correlation (DIC).