Coupled Thermal-Mechanical Numerical Analysis of a Wiring Harness Structure Affected by Random Engine Vibration

The interaction of thermal and mechanical forces generated by internal combustion engines on wiring harness protection and cable insulation is investigated. The engine vibration is generated by a variety of forces acting simultaneously on radial and tangential planes, leading to a very complex frequency signature of the process. This vibration creates three dimensional (3D) displacements with different accelerations on the wiring harness attached to the engine. In some special cases, higher vibration levels (often found on Diesel engines) added to the temperature generated by the engine, may cause several damages on cable structure due to the sequentially mechanical contact between conduit and cable. Based on the actual harness routing on the engine, random vibration functions with magnitude and frequency ranges located within the regular engine vibration spectrum, and a temperature time dependent function, are applied on specific points of our 3D model. A Finite Element Analysis (FEA) is then performed in order to obtain stress and strain results over the entire harness bundle. Critical places on cable insulation and conduit are analyzed and possible solutions to minimize these effects are studied.