A model-driven fault diagnosis method for slant cracks in aero-hydraulic straight pipes is presented in this paper. First, fracture mechanics theory and the principle of strain energy release are used to derive an expression for the local flexibility coefficient of straight pipes with slant cracks. The inverse method of total flexibility is used to calculate the stiffness matrix of straight pipe elements with slant cracks. Second, the Euler-Bernoulli beam model theory is used in conjunction with the finite element method to construct a dynamic model of the cracked pipe. Finally, a contour map method is used to diagnose the slant crack fault and quantitatively determine the crack position and depth. Experimental results show that the proposed method can accurately and effectively identify a slant crack fault in aero-hydraulic pipelines.

提出了一种模型驱动的液压直管斜裂纹故障诊断方法。首先，利用断裂力学理论和应变能释放原理，推导了具有斜裂纹的直管的局部挠性系数的表达式。用总挠性的逆方法来计算具有倾斜裂纹的直管元件的刚度矩阵。其次，将Euler-Bernoulli梁模型理论与有限元方法结合使用，以构建裂缝管的动力学模型。最后，采用等高线图法对倾斜的裂纹断层进行诊断，定量确定裂纹的位置和深度。实验结果表明，该方法能够准确，有效地识别出液压管道中的倾斜裂纹故障。