关键词: 应力强度因子, J 积分, 裂纹, 能量释放率, 矩形梁

Abstract: The rectangular beams were widely used in architectural engineering, cracks would be appeared with the increase of service life and some human factors, and any cracks in it might cause hidden risks. The SIF was a physical quantity that reflected the elastic stress field of the crack tip, which was related to the size of the crack, the geometrical characteristic of the component and the load. Meanwhile, it was very important to find a simple method to solve the SIF for not only the fracture theory but also engineering application, as it was a key content of fracture mechanics. In previous studies, the shape of initial crack must be known to get SIF, but it was very difficult to be seen under the condition of test. This paper took the bending beam as an example, a new method to formulize the SIF for three kinds of cracks in rectangular beam under bending load was proposed by the basis of the conservation J integral.

Key words: Stress intensity factor, J integral, Cracks, Energyrelease rate, Rectangular beams