Fine scale computations of bolted assemblies are generally too costly and hardly tractable within an optimization process. Thus, finite elements (FE) connectors or user-elements are commonly used in FE commercial codes by engineers as substitutes for bolts. In this paper, a non-linear FE connector with its identification methodology is proposed to model the behaviour of a single-bolt joint. The connector model is based on design parameters (bolt prestress, friction coefficient, bolt characteristics...). The axial behaviour of the connector reflects the preload effect and the axial bolt stiffness. The tangential connector behaviour accounts for frictional phenomena that occur in the bolt’s vicinity due to preload thanks to an elasto-plastic analogy for friction. Tangential and normal behaviours identification is performed on a generic elementary single bolt joint. The connector has been implemented in ABAQUS through a user-element subroutine. Comparisons of the quasistatic responses between full fine scale 3D computations and 3D simulations with connectors on various bolted assemblies are proposed. Results are in good agreement and a significant gain in terms of CPU time is obtained.

中文翻译：

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用于螺栓装配仿真的非线性有限元连接器

螺栓装配的精细计算通常成本太高，而且在优化过程中很难处理。因此，有限元 (FE) 连接器或用户元素通常被工程师用于 FE 商业代码中作为螺栓的替代品。在本文中，提出了一种非线性 FE 连接器及其识别方法来模拟单螺栓接头的行为。连接器模型基于设计参数（螺栓预应力、摩擦系数、螺栓特性...）。连接器的轴向行为反映了预紧效应和轴向螺栓刚度。由于摩擦的弹塑性类比，切向连接器行为解释了由于预加载而在螺栓附近发生的摩擦现象。切向和正常行为识别是在通用基本单螺栓接头上执行的。连接器已通过用户元素子程序在 ABAQUS 中实现。建议比较全精细尺寸 3D 计算和 3D 模拟与各种螺栓装配上的连接器之间的准静态响应。结果非常一致，并且在 CPU 时间方面获得了显着的收益。