Manufacturing process operation and product quality are determined in large part by the friction which acts between the tooling and workpiece surfaces. Sophisticated numerical process analyses are hindered by a lack of accurate descriptions of the frictional boundary conditions which exist in the extreme environments of manufacturing operations. Manufacturing process control is based on measurements of the states of processes, but the important frictional conditions cannot be directly measured. Research work is proposed to develop a sensor capable of measuring friction stress distributions in material deformation processes. The sensor will have sufficient resolution to measure very local friction effects over a distributed area on the process tooling. It will be designed so as to have minimal effect on the process and to be useful in production processes. The use of the sensor will be demonstrated in a process control application. The basic sensor configuration is an array of miniature piezoelectric force sensing elements in a structure which fits below the surface of process tooling.
