Estimation of the Real Area of Contact in Sliding Systems Using Thermal Measurements

The objectives of this paper are to develop a means to estimate the real area of contact in sliding systems using thermal measurements and to provide experimental design guidance for optimal sensor locations. The methods used are a modified cellular automata technique for the direct model and a Levenberg–Marquardt parameter estimation technique to stabilize inverse solutions. The modified cellular automata technique enables each piece of physics to be solved independently over a short time step, thus reducing a complicated model to a sequence of simpler problems. Overall, the method proved successful. The major results indicate that appropriately selected measurement locations can determine the contact distribution accurately. The best measurement location is found to be just downstream of the nominal contact zone in the moving body. This is significant since direct access to the contact zone is usually impossible. Results show that it is best to locate a sensor in the moving body. However, placing the sensor in the static body can also provide a reasonable image of the contact distribution. This is useful because the static body is easier to instrument than a moving body. Finally, the estimation method worked well for the most complex model utilized, even in a suboptimal measurement location