Effect of Aircraft Gear Positions and Gear Configurations on Load Transfer Efficiency of Airfield Rigid Pavement Joints

Abstract

Load transfer efficiency (LTE) is commonly used to evaluate degree of load transfer in case of jointed concrete pavements. The concept of load transfer is very important and fundamental to Federal Aviation Administration's (FAA) rigid pavement thickness design procedures. The FAA procedure assumes 25% of stress applied to the edge is transferred across a joint to the adjoining slab. Degree of load transfer across a joint was found to be different under a static and moving aircraft gear. Moreover, as an aircraft traverses a joint, the wheels might be oriented perpendicular or parallel to the joint. The slab bending phenomenon tends to be different under different gear configuration in various positions with respect to the joint. The effect of differential stress distribution along the joint under various modern day aircraft gear configurations in different positions was studied using a 3D-Finite Element analysis program FEAFAA. It was found that load transfer across a joint is a function of number of loaded areas along the joint edge. Overall the differences in LTE were insignificant for similar aircraft in different positions along the joint.