A rubber band may be hung to a shaft of a motor, a device structure changing rotational motion to linear motion, and a linear motion axis. A weight hangs on the end of the rubber band. If a rotational speed at which the motor is rotated to resonate with the self-vibration of the rubber band is maintained, the rubber band is broken when the vibration of the rubber band becomes gradually larger and eventually comes out of the elastic limit. The shaft of the motor and a length of a shaft of a rotation control device may be changed. An optical sensor may measure that the amplitude becomes larger due to the resonance. The elastic limit of various elastomers may be confirmed.;COPYRIGHT KIPO 2019
展开▼
