Tunnel boring machine cutterhead crack propagation life prediction with time integration method

Abstract

Fatigue damage is one of the most common failure modes of large-scale engineering equipment, especially the full-face tunnel boring machine with characteristics of a thick plate structure bearing strong impact load. It is difficult to predict the location and propagation life of crack of cutterhead under strong impact load. Unseasonal maintenance of equipment caused by inaccurate prediction of life cycle of cutterhead seriously affects the construction efficiency of the equipment and the life safety of the operators. Determining the crack location of tunnel boring machine cutterhead structure under strong impact load and predicting the crack propagation life are difficult scientific problems. To solve them, first, the location of the stress concentration of the cutterhead is determined by using finite element analysis method of statics. Second, prediction model for crack propagation life of tunnel boring machine cutterhead characteristic substructure based on time integration is built. And the test of crack growth of cutterhead characteristic substructure is performed. The feasibility and accuracy of the prediction model are verified by contrasting crack prediction models and the results of the test. Finally, the life prediction of tunnel boring machine cutterhead of water diversion project in Northwest Liaoning Province is carried out by using crack propagation model based on time integration. Results show that the maximum error of theoretical prediction and experimental results of crack propagation is 16%. So the feasibility of crack propagation model based on time integration in predicting the crack growth of cutterhead is verified. It is predicted that the tunnel boring machine cutterhead panel can work normally for 5.9 km under the condition of ultimate load. Building the crack propagation model considering the influence of plate thickness and strong impact load has important research value for improving the working efficiency of engineering equipment, prolonging service time, and improving the working safety.

A modular design method based on TRIZ and AD and its application to cutter changing robot

“…Particularly for the excavating with long distance, it would unavoidably lead to severe wear and fracture failure. 22,23 If the worn cutters could not be changed in time, it would increase the cutter consumption and extend the construction period. Therefore, replacing the worn cutter is an inevitable work during construction.…”

Numerical Study of the Propagating Properties of a Laser-Generated Surface Acoustic Wave Interacting with a Bracket Structure

“…It could be seen from the analysis that the local maximum stress was located on the inner side of the cutterhead beam support plate; this could suggest the dangerous position where the cutterhead was prone to crack. Li et al [6] presented a finite element analysis for the maximum thrust condition. The flange of the cutterhead was fixed, the three loads of the cutters were loaded on the seat, and the maximum stress position of the front panel of the cutterhead appeared on the edge of the cutter seat.…”