The contact stiffness of the joint surface directly affects the static and dynamic mechanical behavior, and accuracy of the machine tool. A new elastoplastic contact stiffness model is proposed by considering continuous and smooth contact characteristics and substrate deformation. First, the interpolation interval of cubic Hermite polynomials is improved to meet the continuous and smooth change of contact parameters during asperity deformation. Then, the micro-contact mechanism considering substrate deformation is explored by establishing an asperity-substrate system model. Furthermore, combined with statistical principles, a new contact stiffness model of the joint surface is established. Finally, the correctness of the built model is verified by comparing with experimental data and different contact models. The simulation results show that the model changes continuously and smoothly in the three deformation regions. The substrate deformation mainly affects the asperities in the elastic contact stage. The smoother is the surface, the more significant is the influence of substrate deformation.

接合面的接触刚度直接影响机床的静态和动态机械性能和精度。通过考虑连续平滑的接触特性和基底变形，提出了一种新的弹塑性接触刚度模型。首先，改进三次 Hermite 多项式的插值区间，以满足粗糙变形过程中接触参数的连续平滑变化。然后，通过建立凹凸-基板系统模型，探索考虑基板变形的微接触机制。此外，结合统计原理，建立了新的关节面接触刚度模型。最后，通过与实验数据和不同接触模型的对比，验证了所建模型的正确性。仿真结果表明，模型在三个变形区域连续平滑变化。基板变形主要影响弹性接触阶段的凹凸不平。表面越光滑，基材变形的影响就越显着。