基于界面几何优化的双金属内螺纹连接强度提升研究OA

To enhance the service stability of high-strength bolted connection structures under complex operating conditions,a systematic study is conducted on the bonding performance of the internal thread region,and an optimization scheme for the interference fit based on trapezoidal tooth structure is proposed to improve the connection strength of internal threads.Firstly,the finite element model for a representative bimetallic internal thread structure was established using Abaqus software.Comparative analyses were conducted based on varying numbers of trapezoidal teeth,and it was determined that the three-tooth structure exhibited the best resistance to separation under axial tensile load.Then,focusing on the three-tooth structure,the mechanical response laws under equal interference(0.035 mm)were investigated for this structure with different angles ranging from 110° to 130°,revealing the influence mechanism of angle variation on interfacial bonding strength.The results showed that when the angle was 115°,the interface had stable contact and uniform stress distribution,and the bonding strength was the best.Finally,the pull-out test results for the optimal simulation structure(trapezoidal tooth,three teeth,with an angle of 115°)showed that the experimental and simulated force-displacement curves exhibited consistent trends,with a relative error of critical failure load less than 4%,confirming the reliability of the finite element model.The research results provide theoretical support and design guidance for optimizing the connection performance of internal thread structures,offering valuable engineering insights for the reliability improvement of bolted connection systems in heavy-duty equipment such as diesel engines.