Development of Miniature Tensile-Test System of Intermediate Strain Rate Based on Electromagnetic Launch

To study the dynamic properties of intermediate strain rates for filiform or filmy materials, a miniature tensile-test system with an intermediate strain rate based on magnetic resistance actuation is designed herein. The loading part of the system is formed by inertial movement and an electromagnetic launcher, and the testing part is formed by high-speed optical noncontact measurements using a microforce sensor. Constant tension and intermediate speed are realized by designing the inertial motion of a large-mass combined accelerator. Friction and vibration are offset using magnetic attraction. The electromagnetic acceleration force was eliminated by adjusting the length differences, construction, and relative motion of the structures. The stress-strain curves are obtained by synchronizing the strain signal measured using the optical extensometer method and the stress signal measured using the microforce sensor. The system is verified to be miniature, stable, easy to control, accurate for strain rate, economic, and used for small samples. The stability and reliability of the system are verified using speed testing and motion-state photography. Therefore, the designed system is miniature, easy to control, highly cost-effective, and can be used for filiform or filmy samples.