Technical Glossary Modulus of resilience

[Modulus of resilience]

The modulus of resilience is an indicator of the energy a material absorbs during the impact of an object. It is the ratio of energy an object has during impact and rebound when a test piece is struck by a falling object with a given mass from a given height.
Measurement of the modulus of resilience is standardized in JIS K 6255 and can be a Lupke impact resilience test using a pendulum to calculate the value from the drop and rebound height and a tripso-impact resilience test using a solid disk to calculate the value from drop and rebound angles.
A load W is dropped from a height h1 and strikes a test piece, bouncing to height h2, the energy E absorbed by the rubber material and the modulus of resilience R (%) are indicated in the following equations:

The modulus of resilience can be calculated from these equations if the drop and rebound heights are measured.
At R=0 (%) , a dropped object will stop without bouncing back; at R=100 (%) , it will bounce back to the same position as that from where it was dropped. In addition, (100-R) % will be converted to heat energy by the friction in the rubber. The modulus of resilience for a common rubber material will be markedly affected by the temperature, though our firm's gel is slightly affected by temperature as well as having a higher level of damping.