TBM刀盘焊缝参数对缺口应力集中的影响

Influence of Weld Parameters of TBM Cutterhead on Notch Stress Concentration

为了对全断面掘进机(TBM)进行合理化的刀盘焊缝设计,弥补整体设计方法局部强度不足。根据刀盘结构及应力集中分布特点,建立T型焊缝设计细节参数化模型,采用缺口应力理论,分析焊缝设计参数的影响规律。结果表明:基于虚拟缺口半径法的名义应力积分方法具有较高的准确度,误差范围在0.2以内,焊缝设计倾角参数变量控制下,相同大小载荷弯曲产生的应力集中水平在拉伸应力集中水平的两倍左右;设计时应尽量保证结构对称性以及应力分布均匀性,并适当的增大内外坡口倾角以增大局部细节,增强结构承载能力。

In order to rationalize the cutter head weld design of TBM, the local strength of the overall design method is insufficient. According to the structure of cutter head and the characteristics of stress concentration distribution, a parameterized model of T-type weld design details is established. The influence law of weld design parameters is analyzed by using the notch stress theory. The results show that the nominal stress integration method based on virtual notch radius method has high accuracy and the error range is less than 0.2. Under the control of the design inclination parameter variable, the stress concentration level produced by bending under the same size load is about twice the tensile stress concentration level;the structural symmetry should be guaranteed as far as possible in design. The uniformity of stress distribution and the inclination of the inner and outer grooves are appropriately increased to increase the local details and enhance the bearing capacity of the structure.