Research On Topology Optimization Design Of Cutter Head And Shield Body Of Earth Pressure Balance Shield Machine

With the gradual expansion of the scale of China’s subway,the terrain and geology across more complex and diverse,shield machine as the basic equipment of shield tunneling construction,its performance is a decisive factor affecting the quality and efficiency of construction.As the core component of the tunneling system and the main consumables of tunnel construction,the reasonable configuration of shield cutter can improve the tunneling efficiency and reduce the construction cost.As the structural parts of the shield machine,the cutter head and the shield body are of great significance to optimize the parts of the shield machine while ensuring the reliable construction.This thesis takes the shield machine in a construction section of Jinan subway as the research object,analyzes the rock breaking of the hob used by the shield machine,analyzes the structural performance and structural optimization of the cutter head and the shield body,and provides a theoretical basis for the design of the cutter head and the shield body in the construction process.The main contents are as follows:(1)Analyzes the geological conditions of subway tunnel construction section and expounds the calculation theory of earth pressure for two kinds of tunnel construction according to the characteristics of soil layer.Research the selection basis of shield machine,and the selection analysis of shield machine is carried out according to the geological conditions of the tunnel construction section.(2)The rule of tool layout of shield tunnel is analyzed,the basic form of hob failure and the mechanism of hob rock breaking during construction are studied.Establish a three-dimensional model of rock breaking with a single blade hob,taking the diameter of hob ring and the penetration degree of rock breaking as variables,the hob rock breaking dynamics analysis was carried out to analyze the stress of hob ring under different conditions,obtain the best choice scheme adapted to the actual construction.(3)The thrust and torque of the cutter head of shield machine are analyzed,and the calculation model of thrust and torque is established.Statics analysis is carried out on the three typical working conditions of the cutter head: normal driving condition,maximum thrust condition and static torsional release condition.Modal analysis is carried out on the cutter head structure,and the dangerous working condition of the cutter head in the construction process is obtained through comparative analysis.The statics and modal analysis of the shield body are carried out to verify the structural performance of the cutter head and shield body.(4)Research the principle of variable density method for topology optimization and the optimization model of SIMP variable density method.Under the condition that the structural strength and stiffness requirements are met,based on the results of static analysis,the topology optimization analysis of the cutter head and shield body is carried out by SIMP variable density method based on the strength constraint minimization mass,according to the analysis results,the cutter head and shield body are optimized.Static analysis and modal analysis were carried out on the optimized cutter head and shield model,and compared with the analysis results before optimization,the rationality of the optimized structure was verified.