Finite element simulation analysis of assembly mechanics for shape memory alloy pipe joints

JIA Xiaoli; YANG Mo; GONG Xudong; LI Xingtao; LIU Haipeng

doi:10.16579/j.issn.1001.9669.2026.08.016

Abstract：[Objective]The connection performance of shape memory alloy pipe joints and its key influencing factors were investigated,and the action mechanism of various parameters on connection strength was clarified.[Methods]Firstly,shape memory alloy,an assembly mechanical model was established by combining the ideal elastoplastic model and the maximum shear stress yield criterion,and analytical solutions were derived to provide a benchmark for simulation verification.Secondly,the Boyd-Lagoudas constitutive model was introduced via the UMAT user subroutine of Abaqus software,and a full-scale finite element model was constructed to complete the mechanical simulation of the assembly process.Then,a pull-out analysis step was defined,and the axial pull-out force was adopted as the core index to quantify the connection performance.Finally,parametric analysis was performed to investigate the influence laws of geometric dimensions,operating temperature and critical transformation strain.[Results]The results show that the errors between the simulated start and end phase transformation stresses during diameter expansion and the analytical solutions are 2.11％and 0.96％respectively,and the contact stress error ranges from 4.6％to 10.2％,indicating favorable simulation accuracy.The increase of wall thickness,interference fit and pipe length of the joint all improves the axial pull-out force,among which the pipe length enhances the pull-out performance by expanding the contact area.The larger the critical transformation strain,the greater the recoverable deformation and the better the connection performance.The influence of operating temperature on pull-out force is negligible within the range of 278 K to 318 K.The results provide reference for the engineering application of shape memory alloy pipe joints.