The gear pair model with semicircular initial crack is established. The mode 1 stress intensity factor is calculated when the radius of the leading edge of the semicircular crack is 1.4mm and the driving wheel torques are 200N · m, 400N · m, 600N · m and 800N · m respectively. As shown in the figure, the ki distribution curve under different torques is shown.
It can be seen from the figure that when the torque is 200N · m and 400N · m, the change rate of stress intensity factor at the crack front is relatively small; Under the torque of 600N · m, the value of Ki is 1499.3mpa · MML / 2; At 800N · m torque, the value of Ki is 2018mpa · MM1 / 2. It can be seen from the curve that the stress intensity at the crack tip increases with the increase of torque, and still presents a symmetrical distribution, which is low in the middle and high at both ends.