Experimental Failure Analysis of Glass-Epoxy Laminated Composite Bolted-Joints with Clearance Under Preload

In this study, a failure analysis of glass-epoxy laminated composite bolted-joints with bolt/hole clearance under various torques was carried out. To estimate the effects of joint geometry and fiber orientation on the failure strength and failure mode, parametric studies were conducted experimentally. The two different geometrical parameters were the edge distance-to-hole diameter ratio (E/D) and plate width-to-hole diameter ratio (W/D), E/D ratio was selected from 1 to 5, and W/D ratio was chosen from 2 to 5. The bolt preload torque was also carried out as 0, 3, and 6 Nm. To investigate the material parameters effect, laminated plates were oriented as three different stacking sequences [90(o)](8), [45(o)](8), and [0(o)](8). The experiments were carried out with a clearance between the diameters of the bolt and the circular hole of 5 and 6 mm, respectively. According to experimental results, failure mode and bearing strength are strongly influenced by both material parameters and geometrical parameters. Additionally, when a torque is applied to the bolted-joints, the failure mechanism is affected by its increasing values