| 摘要 |
PURPOSE:To accurately obtain the mean break length of a fiber, regardless of the type of a matrix reinforced fiber by counting the number of fiber breaks generated within a certain division of a test piece from an AE signal arrival time difference, and obtaining the mean break length of the fiber, when the count number reaches a constant value. CONSTITUTION:A set of AE conversion elements 5 and 5a is fitted to a test piece 1, and AE due to a fiber break is detected. In addition, the number of breaks N generated in a certain division L of the test piece 1 is counted on the basis of an AE signal arrival time difference, and the limit of fiber breaks is identified, when the count number N reaches a constant value. In this state, the mean break length lm of the fiber is obtained as lm=L/(N+1). As a result, the measurement value of surface shear strength can be obtained, upon completion of a test, and substantial manpower saving can be achieved. Also, a measurement value independent of personal capability can be obtained. |
