Abstract
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.
Highlights
Hydraulic pipes have a wide range of applications in the aerospace field
Research on vibration failure and crack fault diagnosis of aero-hydraulic pipelines is extremely significant for prolonging the service life of aero-engine hydraulic pipeline systems
The local flexibility coefficient must be determined to calculate the stiffness matrix of the elements of a straight pipe with a slant crack and is key in constructing a corresponding finite element model
Summary
Hydraulic pipes have a wide range of applications in the aerospace field. At present, the development of high-pressure, lightweight, and intelligent applications of aero-equipment require hydraulic pipes to operate under severe fluid pulsation over extended periods. The local flexibility coefficient must be determined to calculate the stiffness matrix of the elements of a straight pipe with a slant crack and is key in constructing a corresponding finite element model. In-plane cracked beam theory is used to determine the additional strain energy of each thin plate, and numerical integration is used to obtain the local flexibility coefficient of the straight pipe element with slant cracks. The stress intensity factor of the crack region of each rectangular integral strip for a slant crack in a hydraulic straight pipe under the combined action of the axial force, the shear force and the bending moment is KI1. Considering the influence of the shear force and the shear coefficient, the local flexibility coefficient of a straight pipe with slant cracks is c11
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
