| 摘要 |
PURPOSE:To improve the reliability of measurement technique by sticking a strain gauge on a metallic rod, measuring the acceleration of one end surface which is generated when an elastic wave generated by giving a shock to the other end surface of the rod reaches the former end surface, and estimating the impulse response of the strain gauge. CONSTITUTION:A bullet 1 is struck on the end surface and the metallic rod 2 is used as a medium where the elastic wave generated by the shock is propagated. The metallic rod 2 has small section size which is small enough to make a one-dimensional wave equation hold and is also long enough to regard the elastic wave motion generated by the shock as a pulse. The strain gauge 3 to be evaluated is adhered nearby the end surface of the metallic rod 2. A mirror surface 4 is formed on the end surface of the metallic rod 2 where the shock is not given and the acceleration of the end surface of the rod is measured by a laser interferometer. When the one-dimensional wave equation is solved in consideration of border conditions, acceleration which is twice as large as the product of the elastic wave propagation speed and strain speed is generated on the mirror surface 4 of the end surface of the metallic rod 2. Based on this physical relation, impulse strain is measured from the accurate measurement result of the acceleration. |
