What type of neck is under the head of a carriage bolts, a stepbolt and an elevator bolt ?
马车螺栓，阶梯螺栓和电梯螺栓的颈是什么形状？
2
An improved method of stress analysis about bolt screw with interference fitting is provided as the first step of fatigue life-prediction for the joint.
针对过盈螺纹的疲劳寿命估算进行了工作，求解应力是寿命估算的第一步。
3
In the second step, the prestressed cable is used as reinforced support to the roof plate, and the reinforcement by bolting and grouting with inside grouting bolt is applied to base Angle.