Article
Mechanics
Yu Chang, Jianguo Ding, Hui Fan
Summary: Bolted joints play a crucial role in the static and dynamic performances of mechanical systems. This study proposes an interfacial micromechanics modeling method using fractal theory to predict contact characteristics and incorporates the interaction effect caused by successive tightening of multiple bolts. Three contact models for bolted joints are examined and compared using different numerical methods. Experimental validation shows the practicality and accuracy of these models, which have their own advantages and limitations depending on the complexity of the bolted structure, computational efficiency requirements, and research focus.
Article
Engineering, Mechanical
Dongwu Li, Daniele Botto, Ruozhang Li, Chao Xu, Wenming Zhang
Summary: This paper presents experimental and theoretical modeling studies on the tangential contact stiffness and friction hysteresis of bolted joint interfaces under transversal vibration. A new test rig was developed to measure the interface fretting response of bolted joints. A multi-scale contact modeling method was proposed to calculate the tangential contact stiffness and reproduce the friction hysteresis of bolted joint interfaces. The effectiveness of the proposed method was verified by comparing the simulation results with the experimental counterparts in different cases of tangential loading.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Mechanics
Wenbo Shi, Zhousuo Zhang
Summary: In this study, an improved contact stiffness model is presented to consider the elastoplastic behavior of contacting asperities on micro-scale and the contact pressure distribution of bolted joint interfaces on macro-scale. The model overcomes the shortcomings of the contact stiffness without elastoplastic behavior and reveals the inhomogeneous distribution features of interfacial contact stiffness in bolted joints. The results show that the proposed model can be used in interface modeling of jointed structures.
COMPOSITE STRUCTURES
(2022)
Article
Engineering, Mechanical
Kai Jiang, Zhifeng Liu, Congbin Yang, Caixia Zhang, Yang Tian, Tao Zhang
Summary: This study investigates the influence of rough surfaces on the mechanical properties of joint surfaces. A mechanical model of the joint surface considering asperity interaction is established based on fractal theory. A new stiffness model based on strain energy method is proposed and validated through experiments. The research also includes the analysis of bolt tightening with different friction coefficients using finite element analysis. Results show that neglecting the stiffness effect of the bolted joint surface leads to an overestimated equivalent stiffness of the system.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Engineering, Mechanical
Dongwu Li, Chao Xu, Ruozhang Li, Wenming Zhang
Summary: A new random fretting test method was developed in this study to investigate the evolution of contact parameters in bolted joint interfaces under wear. The effects of initial bolt preload, excitation level, and surface roughness on the contact parameters were discussed. This research is of great importance for understanding the fretting wear behavior of bolted joints and dynamic analysis of joint-dominated structures.
Article
Mechanics
Cheng-Ya Li, Gang-Feng Wang
Summary: The study adopts a constant mean contact radius from the original Greenwood-Williamson model and deals with asperity interactions by arranging random distributed contact spots into a hexagonal distribution. Finite element simulation is used to determine the load-area relation up to almost complete contact in a representative unit with symmetrical boundary conditions. Compared to the GW model without asperity interactions, interactions induce larger loads for a given contact fraction. The obtained load-area relation is extended to a general formulation, showing good agreement with direct finite element simulations and being applicable for a large range of contact fraction. This model provides an efficient method to predict the overall contact response of rough surfaces and reduces computational burden greatly.
Article
Engineering, Multidisciplinary
Gengxiang Wang, Liang Wang, Yuan Yuan
Summary: This investigation validates the effect of rough contact surface on the dynamic responses of multibody systems based on fractal theory. A new contact force model is proposed and validated through simulations and experimental data, demonstrating its accuracy and generality.
APPLIED MATHEMATICAL MODELLING
(2022)
Article
Engineering, Multidisciplinary
Pingchao Yu, Lunxu Li, Guo Chen, Mohan Yang
Summary: This study proposed a new analytical model of bolted joint to effectively describe the joint's nonlinearity and damping. The bolted joint mainly causes stiffness loss and damping nonlinearity in the rotor system, which can be reduced by decreasing flange length, friction coefficient, and interference fit of the spigot.
APPLIED MATHEMATICAL MODELLING
(2021)
Article
Acoustics
Seyed Iman Zare Estakhraji, Mitchell Wall, Jacob Capito, Matthew S. Allen
Summary: Bolted joints are significant in built up structures due to their damping and nonlinearity. This study presents a prediction of the nonlinear damping and stiffness of a structure using a detailed finite element model, which considers preload forces and Coulomb friction in the bolts. The predictions are compared with measurements at different preloads, showing reasonable agreement when using a Coulomb friction coefficient of 0.2 for simulations.
JOURNAL OF SOUND AND VIBRATION
(2023)
Article
Engineering, Mechanical
Hua Zhou, Xinhua Long, Guang Meng, Xianbo Liu
Summary: A revised fractal contact model considering asperity interactions is proposed and verified to be closer to experimental results. Additionally, an equivalent normal stiffness model for bolted joints considering the contact of two rough surfaces is proposed to determine the suitable initial preload.
JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME
(2022)
Article
Nanoscience & Nanotechnology
Guosheng Lan, Wan Sun, Xueliang Zhang, Yonghui Chen, Wenbing Tan, Xiang Li
Summary: A new model of asperity elastic-plastic contact is proposed in this study, supported by an analytical model of normal contact stiffness and damping considering the influence of contact area distribution and elastoplastic deformation mechanism. Through numerical simulations, the impact of factors such as normal contact load, fractal dimension, fractal roughness, and plastic index on the joint surface's normal contact stiffness and damping is analyzed. Comparison with different models demonstrates that the elastoplastic contact deformation mechanism significantly affects the results, with greater normal contact stiffness and damping when considering the elastoplastic deformation mechanism.
Article
Engineering, Mechanical
Longfei Tan, Chengyu Wang, Yang Liu, Wei Sun, Wei Zhang
Summary: This study focuses on the static hysteresis behavior of bolted joints and the identification of joint parameters using a bolt analytical model. The research analyzes the relationship between hysteresis behavior and joint parameters, as well as the effects of non-parallel bearing faces on the joint parameters. The results confirm that introducing friction coefficients in a single bolt lap beam can enhance the accuracy of predicting the stiffness and damping of bolted joints.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Article
Engineering, Electrical & Electronic
Yunshuai Chen, Pengyang Li, Jian Sun, Miao Shang, Limin Shao
Summary: In this study, a fractal model of thermal-elastic-plastic contact normal load is established based on fractal theory. The effects of temperature difference on the joint surface properties are investigated through numerical simulations.
Article
Mathematics, Interdisciplinary Applications
Weikun Wang, Qi An, Shuangfu Suo, Guoying Meng, Yibo Yu, Yuzhu Bai
Summary: A novel three-dimensional fractal model is proposed for calculating normal contact stiffness. The model is based on an axisymmetric cosinusoidal asperity and incorporates both the three-dimensional fractal theory and the contact mechanics theory. The simulation results demonstrate that the presented model has a maximum relative error of 4.35%, while the Pan model has a maximum relative error of 29.58%. The study also discusses the influence of different fractal parameters on contact stiffness and provides insights based on the shape of the asperity. This research provides a new model for calculating normal contact stiffness and offers a foundation for studying contact properties in mechanical interfaces.
FRACTAL AND FRACTIONAL
(2023)
Article
Mechanics
Yu Cheng, Zhenping Wan, Yingbin Bu, Peiyang Zhou
Summary: In this study, a contact load model that accounted for strain hardening was developed for rough surfaces. The model integrated asperity interactions and a three-dimensional fractal contact model, considering strain hardening. The model was evaluated and compared to existing fractal contact models and experimental results, showing better consistency. The contact load decreased with increasing strain hardening exponent and exhibited sensitivity to the fractal dimension, with nonmonotonic characteristics. This model provides deeper insights for predicting the contact characteristics of engineering structures.
