Composite materials are increasingly becoming more common in ground transportation. As this occurs thicker panels become necessary, as compared to composite panels used in aviation, in order to withstand high impact loads and day to day degradation. The effectiveness of these panels is often limited by the strength of the joint in which the panel is attached to the frame of the vehicle. Investigating methods of reducing strain concentrations within these joints would increase the effectiveness in using composite materials in ground transportation applications by increasing the load necessary for joint failure to occur.
In this study, fiber optic strain gages were embedded in a composite panel near the bearing plane of a thick, single-lap, bolted joint. These gages allow for strain concentrations to be experimentally determined within the thickness of the specimen. Several clearance values were then implemented in the bolt to determine their effect on the strain concentrations. This experimental data is validated against finite element models in ANSYS  LS Dyna. Results determine the optimum and worse case scenarios for clearance in a thick, single-lap composite joint.