Evaluation of forming forces in ultrasonic incremental sheet metal forming

In this paper, a new type of sheet metal forming technology using ultrasonic vibration applied to SPIF (single point incremental forming) process is presented. Forming force during forming process can induce fracture and affect accuracy of the sheet metal. Design of ultrasonic sheet metal forming equipment can be based on this study, which takes into account magnitude and changing law of the forming force. ABAQUS finite element software was used to simulate and analyze influence of different frequencies and amplitudes of ultrasonic vibration on the forming force in single point incremental forming process. Results show that ultrasonic vibration can reduce forming force and improve surface quality of the forming process. In addition, an experimental system using ultrasonic single point incremental forming was designed. Effect of the amplitude on ultrasonic vibration was studied experimentally. Experimental results were consistent with the result from finite element simulation.