| 摘要 |
PURPOSE:To estimate the growing direction of cracking by calculating a stress component from outputs of plural three-axial rosette gauges, calculating the extremal value of the stress component and its time, and further calculating a coefficient of stress expansion corresponding to the external value. CONSTITUTION:Plural three-axial rosettes 1-13 are stuck on a thin-film base board 3a which has a slit 6a at the center part dispersedly at equal intervals on a periphery having its center at one end of the slit 6a. One crack gauge 15 is stuck at the opposite side of the slit 6a and those are led to an arithmetic device 7a through a connector 16. Then, the arithmetic device 7a is provided with a dynamic strain gauge, an extremal value detecting circuit, its arithmetic circuit, a timer, and a storage device for the coefficient of stress expansion and the output of the crack gauge so as to calculate, store, and record the coefficient of stress expansion, thereby calculating the coefficient of stress expansion from data of strain gauges at the periphery of a crack. |
