| Abstrakt: |
Due to the complex geometric structure of screw thread, it is difficult to mesh the internal and external screw surfaces of screw thread parts in the finite element analysis of screw thread parts, which often leads to difficulties in finite element modeling of screw thread structure and poor convergence of numerical calculation. In this paper, based on the fact that the geometry of any cross section of the thread perpendicular to its axis is the same, the standard helix formula formulated by the International Organization for Standardization (ISO) is selected, and the three-dimensional eight node element is used to accurately establish the finite element model of the threaded connector. The model not only considers the influence of screw thread elevation angle on itself, but also arranges the element layers of each pitch in order, the node numbers on each layer are orderly distributed, and the nodes on the internal and external screw thread surfaces are close to each other. These characteristics enable the model to accurately map the mechanical properties of threaded connection structures in engineering, optimize the convergence state of numerical calculation of the model, and facilitate the mechanical profile analysis of the calculated results. To verify the validity of the established finite element modeling method of threaded connection structure, the relationship between tightening angle and preload force in screw structure, the distribution of axial force in screw structure are deduced and theoretically analyzed, and the axial force distribution of M12 standard bolt is calculated as an example. The results of numerical experiments show that the relationship between the tightening angle and the preload of the screw connection structure is consistent with the theoretical analysis results, the axial force distribution of M12 bolt is consistent with the theoretical calculation results, the stress concentration coefficient at the root of the thread is consistent with the experimental results, the stress distribution and plastic strain distribution are consistent with the actual engineering measurement. A parametric modeling software for bolt and nut is developed base on proposed the finite element modeling scheme of threaded connection structures. The software can quickly view and generate three-dimensional finite element models of different types of bolts and nuts according to the input thread diameter, pitch number and other parameters. In the engineering analysis and optimization design, it not only avoids the tedious repetitive work of designers, but also improves the design accuracy and work efficiency, which can better meet the actual engineering needs. [ABSTRACT FROM AUTHOR] |
