The Interfacial Pressure Distribution and Thermal Conductance of Bolted Joints

Experimental interface pressure distributions and thermal conductance data are presented for a bolted joint. The variables considered included the bolt torque and associated axial load, the upper and lower plate thicknesses, and the mean interface temperature within the bolt radius. For 7.62-cm-dia Aluminum 6061-T6 plates, axial loads of 6.69 to 13.425 kN (1500 to 3000 lb), three heat fluxes, and mean junction temperatures of up to 310 K were considered. Pressure distribution data obtained with a pressure-sensitive film compared favorably with both theoretical predictions and published experimental data. Thermal conductance data obtained at three radial locations for the bare interface compared favorably with published data. These data also were compared with a previously published correlation for heat transfer in bolted joints. Thermal conductance data for high-conductivity elastomeric gasket materials were obtained to ascertain their suitability for thermal enhancement. The results of this investigation will be useful in the thermal analysis of bolted and riveted joints.