Electromagnetic Cam Driven Compression Testing Equipment

This paper presents innovative equipment for the compression testing of materials under high rates of loading (above 1,000 s⁻¹). The equipment consists of an electromagnetic actuator, a fixed housing containing two flat compression platens, a translating cam and a follower. The electromagnetic actuator makes possible reaching high strain rates with a very precise control of the impact velocity and of the energy transmitted to the translating cam. The cam profile enables compression testing to be performed under the strain rate vs. strain loading paths that are commonly found in manufacturing in order to meet the machine-tool and process combined specifications. Special emphasis is placed on the adequacy of the proposed electromagnetic cam drive compression testing equipment to characterize material behaviour in orthogonal metal cutting because non-proportional loading paths during metal cutting are known to have significant influence on the material stress response. The flow curves obtained by means of the equipment are implemented in a finite element computer program and applied in the numerical simulation of orthogonal metal cutting under different cutting velocities.