A sensing block method for measuring impact force generated at a contact part

Abstract

A new method has been devised for measuring the impact force generated at the contact part in a collision. This new method, here called the sensing block method, is based on a simple structure which is made of a steel cylindrical block with a small cylindrical projection. The top of this projection serves as the contact plane in a collision. The impact force generated at the contact part can be measured using small strain gages mounted on the side surface of the projection. Through the calibration tests, the new method was confirmed to be more effective for direct measurement of impact force with relatively high sensitivity for both normal and oblique impacts. The obtained measurements are almost entirely free from disturbances caused by reflected wave interference. Using this method, an impact experiment on commercially available pure aluminum bars with different lengths and spherical ends was performed. From the experimental results, it was found that the generated maximum force gradually increased in proportion to the square root of potential energy, and that the generated mean stress on the contact part was constant and independent of the radius of curvature of the spherical end and impact velocity.