为解决盾构工作中管片拼装机旋转体由于受力和冲击导致的开裂失效问题，深入研究盾构管片拼装机旋转体失效原因，通过剖析管片拼装机的总体结构及工作机制，将研究重心放在分析盾构管片拼装机旋转体失效机制上，根据分析，管片拼装机旋转体主要有抓取管片和旋转到位时的冲击载荷、管片施加预紧力时的静力载荷2种受力工况。采用简化力学模型对上述工况进行受力分析并采用有限元法对旋转体进行静力学和动力学仿真验证，研究结果表明： 1）拼装机工作过程中旋转体受到来自管片自重产生的弯矩及剪切力，工作过程中受力不均、冲击载荷大、冲击频率随机性强、结构设计不合理及不规范操作是导致旋转体产生裂纹或断裂失效的主要原因； 2）在工作载荷条件下，旋转体从初始位置旋转90°，旋转体所受应力及力矩达到最大值，当旋转速度过快，旋转体承受较大冲击力时极易产生破坏形变，与旋转体受力分析及工作过程中出现的失效状态吻合。根据分析及仿真结果对旋转体受力集中位置进行隔板焊接加固处理并进行仿真验证，仿真结果符合使用要求。在盾构掘进过程中监测管片拼装机旋转体工作状态，结果表明，使用过程中无裂纹失效现象发生。
The rotating body of shield
tunnel segment assembly machine cracks or even malfunctions due to shear force
and impact when applying in shield tunnel segment assembly. To address this,
the causes for failure of the rotating body are analyzed, focusing on the
structure and working mechanism of the segment assembly machine. The analytical
results indicate that the segment assembly machine is subjected to the impact
load of segment grabbing and rotating and the static load of segment
pretightening stress. A simplified mechanical model is employed to examine the
stress state of the rotating body under impact and static loads, and statics
and dynamics simulation validations are conducted using finite element method.
The research results demonstrate the following: (1) The rotating body is
subjected to bending moment and shear force generated by the selfweight of the
segment during the working process of the segment assembly machine. The causes
for cracks or malfunctions of the rotating body are uneven force, large impact
load, random impact frequency, unreasonable structure design, and nonstandard
operation. (2) Under working load condition, the stress and torque of the
rotating body peak when rotates 90° from the initial position. When applying an excessive rotating speed, the
rotating body is prone to damage and deformation due to large impact force,
which is consistent with the stress analysis results. Based on the analysis and
simulation results, a diaphragm is welded to strengthen the stress
concentration position of the rotating body, and the effect is numerically
simulated. This countermeasure is proved to be effective in preventing the
rotating body from cracking or malfunctioning.
