コンクリートひびわれの研究 (1)
割れ目の検出
1964 年 33 巻 4 号 p. 245-250
詳細
1964 年 33 巻 4 号 p. 245-250
For bending fracture test of concrete structures, it is very important to detect the cracks originated in the structure before the actual fracture occurs. For the detection of cracks, a mechanical method, instead of the visual method that is being practised, is devised by the use of an extremely sensitive receiver of vibrating acceleration. Experimentally, certain unusual forms of vibration associated with the energy transfer are observed by the initiation of impulse. The natural frequency of vibration of the test piece seems to be superposed on a very low frequency about 30 cycles per second. It is interesting to note that there is a linear relation between the cracking stress and the square value of the maximum amplitude obtained on a synchroscope.
