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Aiming at the fatigue failure of TBM cutter seat under alternating load, the theoretical calculation and numerical
simulation analysis method of cutter seat crack initiation life are investigated. According to the rock breaking process of disc
cutter, the stress spectrum of cutter seat is obtained. Through the finite element analysis of cutter seat, the dangerous point
position of cutter seat is determined. Combined with Q345D material S-N curve and fatigue damage accumulation theory, the
prediction model of cutter seat crack initiation life is established, and the prediction of cutter seat crack initiation life is
realized. Finally, the crack initiation life of cutter seat is analyzed numerically. The results show that the dangerous part of
the cutter seat is at the "L" shape corner, which is consistent with the actual situation. The crack initiation life of the cutter
seat is 9.46×108 times, 3.00×108 times, 2.13×108 times and 1.25×108 times with the survival rate of 50%, 90%, 95% and 99%.
The errors between the theoretical analysis and simulation analysis results are 4.6%, 4.3%, 2.0% and 8.4% respectively. The
feasibility of the numerical analysis method and the correctness of the crack initiation life prediction mode of the cutter seat
is verified. |