The static friction behavior of an elastic–plastic spherical adhesive microcontact between a rigid flat and a deformable sphere under combined normal and tangential loading is studied by the finite element method (FEM). The contact between the sphere and the rigid flat is assumed to be full-stick, and the sliding inception is related to a loss of tangential stiffness. The intermolecular force between the rigid flat and the sphere is assessed by the Lennard–Jones (LJ) potential, which is applied to the sphere and the rigid flat by a user subroutine. The evolution of the adhesive force with tangential displacement in the full-stick condition is revealed. The results indicate that the increasing effect of adhesive energy on the static friction coefficient gradually diminishes with an increase in the adhesive energy and the external normal load. Finally, based on an extensive parametric study, an empirical dimensionless expression is obtained to predict the static friction coefficient of the spherical adhesive microcontact considering the intermolecular force.

通过有限元法（FEM）研究了刚性平面和可变形球体之间的弹塑性球形粘合微接触在法向和切向联合载荷下的静摩擦行为。假设球体和刚性平面之间的接触是全粘的，并且滑动起始与切向刚度的损失有关。刚性平面和球体之间的分子间力通过 Lennard-Jones (LJ) 势进行评估，该势通过用户子程序应用于球体和刚性平面。揭示了全粘条件下粘合力随切向位移的演变。结果表明，随着粘合能和外部法向载荷的增加，粘合能对静摩擦系数的增加作用逐渐减弱。最后，基于广泛的参数研究，获得了经验无量纲表达式来预测考虑分子间力的球形粘合剂微接触的静摩擦系数。