Slender beam-like structures frequently occur in engineering applications and often interact at discrete locations through joints or connectors. Accurate modeling of such interactions is particularly challenging when different numerical formulations are involved in terms of underlying beam theory, interpolation schemes, and rotation parametrization. In this work, a versatile formulation-independent beam-to-beam point coupling approach is proposed within the framework of the geometrically exact beam theory discretized by the finite element method. The coupling constraints are expressed solely in terms of cross-section kinematics, namely centroid positions and orientations. Suitable generalized deformation measures for positional and rotational coupling are introduced, allowing for general coupling configurations, including relative rotations and non-coincident cross-section centroids in the reference configuration. The contribution of the coupling conditions to the weak form of the balance equations is derived in a variationally consistent manner and can be incorporated directly into the weak form of existing beam finite element models. Constraint enforcement is formulated using a Lagrange multiplier method and a penalty regularization. The proposed approach satisfies key properties such as objectivity, symmetry, and consistency with an stress-free reference configuration. Numerical examples demonstrate the robustness and flexibility of the method for coupling beams with different formulations and discretizations, even when the interaction points are located at arbitrary positions within beam elements.

翻译：细长梁状结构在工程应用中经常出现，并常在离散位置通过节点或连接件相互作用。当涉及不同的梁理论、插值方案和旋转参数化等数值公式时，此类相互作用的精确建模尤其具有挑战性。本文在采用有限元法离散的几何精确梁理论框架内，提出了一种通用且与公式无关的梁-梁点耦合方法。耦合约束仅用截面运动学表示，即质心位置和取向。引入了适用于位置和旋转耦合的广义变形度量，允许一般性耦合构型，包括相对旋转和参考构型中非重合的截面质心。以变分一致的方式推导了耦合条件对平衡方程弱形式的贡献，该贡献可直接融入现有梁有限元模型的弱形式中。约束施加采用拉格朗日乘子法和罚函数正则化实现。所提方法满足客观性、对称性以及与无应力参考构型的一致性等关键性质。数值算例证明了该方法在耦合不同公式和离散方式的梁时的鲁棒性与灵活性，即使相互作用点位于梁单元内部的任意位置。