Accurate evaluation of preload in system with double-bolted connections is critical for the service performance of engineering structures or equipment. However, the theoretical framework for assessing preload is imperfect. An equivalent approach from the tightening process of double-bolted joints to second-order spectral problem of the energy-dependent potential is firstly established. This paper proposes a novel nonlinear model of bolt preload considering physical and geometric parameters by proving the completely integrability of systems used bolted connections. The experimental device for hmeasuring displacement and bolt preload was developed to verify the accuracy of proposed model. Results show that the maximum relative error is not more than 3%. Finally, the influences of elastic modulus, density, holes spacing, and height on preload are analyzed.

准确评估双螺栓连接系统中的预载荷对于工程结构或设备的使用性能至关重要。然而，评估前负荷的理论框架并不完善。首次建立了从双螺栓接头紧固过程到能量相关势的二阶谱问题的等效方法。本文通过证明使用螺栓连接的系统的完全可积性，提出了一种考虑物理和几何参数的螺栓预紧力非线性模型。开发了测量位移和螺栓预紧力的实验装置，以验证所提出模型的准确性。结果表明，最大相对误差不超过3%。最后，弹性模量、密度、孔距的影响，