Advanced Materials Research Vols. 966-967

Abstract: Ultrasonic assisted clinching applies ultrasonic energy to the punch during the process. Prior studies detected a forming force reduction [1]. Current research activity focusses on the possibility to use the positive effects of ultrasonic softening mechanisms in clinching processes to join high-strength steel and aluminium. An ultrasonic unit with a power of 1 kW was installed into a c-shaped clinching bow to overlay a vibration with a frequency of 20 kHz onto the clinching process. This Paper describes the integration of the ultrasonic unit in the clinching process and presents current research results focusing on concept verification.

Abstract: Smart structures consisting of a load carrying structure and smart materials with actuatory and sensory capabilities feature high potential in numerous applications. However, to master the assembly conditions of smart structures, there is a need to integrate additional design parameters such as prestress of the smart material, critical loads and electric contacting as well as insulation into the process development. This paper focusses on the design of an incremental bulk forming process to integrate piezoceramic components into an aluminum tube simultaneously to the manufacturing process. Axial forces imposed on the piezoceramic are investigated numerically and experimentally to verify the design of critical components and the process control. Within this investigation, in situ measurement of the direct piezoelectric effect provides a method to validate the numerical design with regard to failure of the piezo tube and the functional properties of the overall structure.

Abstract: A combination of several manufacturing process steps in a simultaneous manner allows savings in energy costs, reduced investment and economizing logistical efforts. In particular, this investigation deals with manufacturing and joining of a frictionally engaged shaft-hub-connection by lateral extrusion. One key challenge of such new process management is the prior layout of both optimal friction conditions during manufacturing process on the one hand and highly expected static friction interaction of joined components in order to transmit tangential and axial forces on the other hand. Therefore, cylindrical, thin-walled hubs have been manufactured and joined to shafts. Several parameters describing the tribological system between shaft and hub such as contact surface topographies and lubricant, have been varied within this study. By measuring the radial deformation of the hub, the contact pressure is determined and a normal force applied to the contact surface of shaft and hub is calculated. When separating hub and shaft in a destructive manner, an extensive axial tensile force is applied and measured. According to Coulomb's friction law, specific friction coefficients are calculated depending on manufacturing process parameters as mentioned above.