简支梁裂纹位置识别的一种简单方法

AN APPROXIMATE METHOD OF CRACK LOCATION IDENTIFICATION FOR SIMPLY SUPPORTED BEAMS

由等效线弹簧来模拟裂纹引起的软化效应 ,基于铁摩辛柯梁理论得到含裂纹简支梁横向振动的频率计算式 ,由此获得识别裂纹位置的一种近似方法。文中利用梁的二维有限元模态分析数据进行裂纹位置的识别 ,结果表明该法在较宽的高跨比范围内 ,有好的效果 ;

The dynamics of a cracked, simply supported uniform beam is treated for bending vibration based on Timo-shenko's beam theorem. The softening effect due to crack is simulated by an equivalent line spring which connects the two segments of the beam. An expression for natural frequencies is obtained and then an approximate method is concluded for the identification of crack location from frequency measurements. The identifications are processed by using the values of 2-D finite element modal calculations for beams. It is found that the method proposed in the paper is suitable to wide range of height-span ratio of beam and the accuracy of identification is only influenced slightly by depth of crack.