Review
Engineering, Chemical
Kamyar Kildashti, Kejun Dong, Aibing Yu
Summary: This paper reviews the current status of contact force models for non-spherical particles, focusing on their relationships with the geometrical, material, and mechanical properties of the particles. The aim of the review is to improve the existing simplified contact force models used in discrete element method (DEM) simulations by selecting better models. The review covers contact force models based on the extension of the classical Hertz theory, the effects of different variables on contact force, and tangential force models for non-spherical particles. Based on the review, a set of improved contact force models for DEM is recommended to accurately predict contact force and area in emerging areas such as nanoparticles and additive manufacturing.
Article
Acoustics
Tianzhu Wang, Qian Ding
Summary: This paper investigates the modal balancing method for a rotor-bearing system based on nonlinear normal modes (NNMs). The proposed algorithm includes three steps: computing NNMs and expressing nonlinear modal shapes using complex Fourier series, describing unbalance response as a complex amplitude with higher harmonics, and estimating correction coefficients for each harmonic to obtain total unbalance corrections. Hertz contact force and different radial internal clearances of the ball bearings are considered in the balancing simulation. The accuracy and effectiveness of the proposed method are demonstrated by comparing the responses after balancing with NNMs and the linear modal method.
JOURNAL OF SOUND AND VIBRATION
(2023)
Article
Engineering, Geological
Yupeng Jiang, Yidong Zhao, Clarence E. Choi, Jinhyun Choo
Summary: This article introduces a hybrid continuum-discrete approach for efficiently simulating granular impact dynamics. By enhancing the existing methods and introducing new components, the proposed approach can accurately reproduce various parameters of granular impact dynamics. Through experimental validation and parameter studies, key factors for successful simulation are identified.
Article
Engineering, Aerospace
Ziwen Li, Xiangyuan Zeng, Tongge Wen, Yonglong Zhang
Summary: This paper introduces the application of the discrete element method (DEM) in analyzing the scientific origin/evolution of asteroids and the landing/sampling of regolith. It proposes a newly-developed DEM algorithm with the Polygonal Contact Model (PCM) to manage contact between non-spherical granules. The paper analyzes four different contact force models and compares their differences and implications in single-collision and multiple-collision scenarios. The study also discusses the feasibility of softening by decreasing the material's Young's modulus.
Article
Construction & Building Technology
Hong Xiao, Zhihai Zhang, Yihao Chi, Xiaoyu Wang, Haoyu Wang, Ziqing Jiang
Summary: This paper investigates the effects of sand intrusion on the mechanical behavior and vibration behavior of railway tracks. Through field tests and numerical modeling, the study reveals that sand intrusion increases the vibration acceleration of rail and sleeper while decreasing the vibration of the ballast bed. Additionally, high train speeds and axle loads intensify these effects.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Engineering, Chemical
C. X. Li, J. Q. Gan, D. Pinson, A. B. Yu, Z. Y. Zhou
Summary: The study used DEM to investigate the effects of dropping height, deposition intensity, and friction coefficient on the packing properties of ellipsoidal particles. The results showed that increasing dropping height led to higher packing density but less ordered bed, significantly affecting the densification process of ellipsoids. Higher deposition intensity decreased packing density but had slight impact on orientational order, while higher sliding friction coefficient dramatically decreased both packing density and orientational order.
Article
Mechanics
Penghai Deng, Quansheng Liu, Xing Huang, Qi Liu, Hao Ma, Weiwei Li
Summary: The study proposed a method to measure the normal contact stiffness and found that an alpha value of 0.1448 is optimal for simulating rock crack propagation under different conditions. Proper selection of the alpha value can improve the reliability of FDEM numerical simulation results.
ENGINEERING FRACTURE MECHANICS
(2021)
Article
Engineering, Multidisciplinary
Hao Chen, Shiwei Zhao, Jidong Zhao, Xiaowen Zhou
Summary: This study proposes a generalized contact scheme based on a hybrid scheme of material point method (MPM) and discrete element method (DEM) to model multi-body and multi-material interactions. The scheme contains two novel features of particle-particle and particle-structure contact schemes guided by a DEM contact model. It demonstrates that the generalized contact scheme can flexibly capture the mechanical responses of multi-body and multi-material systems in MPM.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2023)
Article
Engineering, Mechanical
Thomas Russell, Abbas Shafiee, Benjamin Conley, Farshid Sadeghi
Summary: The study aimed to use thin film pressure sensors to evaluate pressure distribution between rolling element bearings and a housing, with results applicable for validating bearing fit selection and housing design.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Engineering, Chemical
Yun Zhang, Ali Ozel, Christine M. Hartzell
Summary: Accurate modeling of contact electrification in insulating materials is crucial for predicting and controlling their behavior. This study proposes a mesoscopic model based on the donor-acceptor mechanism, which incorporates findings on surface patch features of identical dielectric materials from experiments. The model enables reproduction of the charge transfer process and development of a macroscopic model that statistically captures this process.
Article
Computer Science, Interdisciplinary Applications
Xiao-Qiong Jiang, En -Long Liu
Summary: Saturation conditions are crucial in the mechanical behavior and interparticle contact system evolution of granular material. This study examines the properties of an interparticle contact network and force chain structure using data from discrete element simulations. The evolution of topological statistic features and force chain structure characteristics influenced by suction conditions are analyzed.
COMPUTERS AND GEOTECHNICS
(2023)
Article
Construction & Building Technology
Peifeng Han, Xingkai Li, Hao Cheng, Hongzhi Qiu
Summary: This study investigated the impact dynamics of three granular materials through numerical simulation using the discrete element method. The results showed that spherical granular material had the best cushioning capacity and the sensitivity of impact pressure to particle shape depended on the initial impact velocity. Moreover, as the velocity increased, the probability distribution function of weak contact force decreased while the strong contact force increased.
CASE STUDIES IN CONSTRUCTION MATERIALS
(2023)
Article
Engineering, Mechanical
Shuaijun Ma, Wenchao Li, Ke Yan, Yeteng Li, Yongsheng Zhu, Jun Hong
Summary: The dynamic contact characteristics of a four-contact-point ball bearing were studied, and it was found that increasing preload causes the contact mode to transition from 3-point to 2-point contact. Under combined load, the ball may experience 2-point, 3-point, and 4-point contact.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Article
Multidisciplinary Sciences
Lasse Tor Nielsen, Thomas Kiorboe
Summary: Unicellular flagellated protists play a crucial role in aquatic microbial food webs, using flagella to swim, create feeding currents, and attract predators. Different flagellar arrangements affect swimming speed, flow structure, and the trade-off between resource acquisition and predation risk. This trade-off varies between species, with dinoflagellates showing a unique ability to balance high clearance rates and stealth behavior through their flagellar arrangement. Understanding these trade-offs is essential for studying eukaryotic communities in pelagic food webs.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Computer Science, Interdisciplinary Applications
Tao Wang, Huai-Zhong Liu, Ming-Li Xiao, Li Zhuo, Hong-Qiang Xie, Jiang-Da He
Summary: This paper proposes an exponential softening bond model to simulate the size effect of Mode I fracture of rock in the discrete element method. The model is based on an exponential damage law and an elliptic yield criterion, and its basic formulas ensure energy balance and accurate simulation results. The simulations show that the proposed model effectively simulates the fracture behavior and eliminates the particle size dependency by fracture energy regularization. Compared with other bond models, the exponential softening bond model accurately represents the fracture toughness, the fracture process zone, and the size effect of Mode I fracture of limestone.
COMPUTERS & STRUCTURES
(2023)
Article
Engineering, Mechanical
Antonella Castellano, Pietro Stano, Umberto Montanaro, Marco Cammalleri, Aldo Sorniotti
Summary: This paper proposes a new control strategy for hybrid electric vehicles, called Model Predictive Control (MPC), and considers the losses in transmission gears. Through a case study on Chevrolet Volt, the results show that the simplified internal model has a minor impact on fuel consumption performance.
MECHANISM AND MACHINE THEORY
(2024)
Article
Engineering, Mechanical
Rui Peng, Gregory S. Chirikjian
Summary: This article introduces a method of designing morphable thick-panel origami structures using reconfigurable linkages, which improves the potential of origami techniques for different tasks and solves the limitations of one-DOF and multiple-DOF folding structures.
MECHANISM AND MACHINE THEORY
(2024)
Article
Engineering, Mechanical
Gaohan Zhu, Weizhong Guo, Yinghui Li, Youcheng Han
Summary: Comprehensive and accurate performance evaluation is crucial for profile synthesis and analysis of higher pair mechanisms. This paper proposes evaluation indices and methods for the transmission performance of planar higher pair mechanisms from different perspectives. It subdivides the transmission performance into element-based performance and joint-based performance and develops novel indices specific to higher pair mechanisms. A graphical mapping method based on element-based performance is also proposed for intuitive analysis. Practical examples validate the effectiveness of the proposed indices and methods for evaluating the performance of higher pair mechanisms.
MECHANISM AND MACHINE THEORY
(2024)
Article
Engineering, Mechanical
Ke Wu, Gang Zheng, Guimin Chen, Shorya Awtar
Summary: Researchers proposed a new modeling method, namely Body-frame Beam Constraint Model (BBCM), to predict and optimize the design of high-precision compliant mechanisms (CMs).
MECHANISM AND MACHINE THEORY
(2024)
Article
Engineering, Mechanical
Youcheng Han, Weizhong Guo, Changjie Zhao, Ziyue Li, Ze Fu, Yinghui Li
Summary: This study proposes a structural synthesis methodology that considers motion, force, and energy characteristics simultaneously to design efficient mechanisms.
MECHANISM AND MACHINE THEORY
(2024)
Article
Engineering, Mechanical
Cristian Enrico Capalbo, Daniel De Gregoriis, Tommaso Tamarozzi, Giuseppe Carbone, Domenico Mundo
Summary: This study proposes a novel flexible multibody formulation that enables efficient updating of models while maintaining small size and high accuracy. Numerical validation demonstrates its wide applicability across various materials and mechanisms, showing promising results in terms of accuracy.
MECHANISM AND MACHINE THEORY
(2024)
Article
Engineering, Mechanical
Weihao Zhao, Junbei Liao, Wei Qian, Haoyong Yu, Zhao Guo
Summary: This paper presents a newly designed compliant actuator using a tensile springs array to address the challenges in achieving linear and consistent elastic properties, low friction, minor hysteresis, and good compliance in series elastic actuators (SEA). The unique geometry of the spring array enables the SEA to have consistent rotary stiffness with minimal friction and hysteresis. The device's performance is evaluated using PID and sliding mode control, demonstrating its constant low rotary stiffness and torque tracking bandwidth, making it suitable for human-robot interaction requirements.
MECHANISM AND MACHINE THEORY
(2024)
Article
Engineering, Mechanical
Mohui Jin, Yukang Luo, Xing Xu, Bowei Xie, Weisheng Wang, Zewei Li, Zhou Yang
Summary: This paper presents a method for evaluating the contact interaction between compliant mechanisms and external objects. By establishing a numerical model and introducing contact springs to describe the contact forces, the deformation and normal contact force/stress can be accurately calculated. The static equilibrium configuration and contact force/stress can be obtained by minimizing the total potential energy function of the system.
MECHANISM AND MACHINE THEORY
(2024)
Article
Engineering, Mechanical
Alejandro G. Gallardo, Martin A. Pucheta
Summary: This paper presents a method for the synthesis of parallel flexure systems using Screw Theory and Linear Algebra. The method is validated through three case studies and offers a simple and precise design with decoupled actuators.
MECHANISM AND MACHINE THEORY
(2024)
Article
Engineering, Mechanical
Xiao Wang, Chenglin Liu, Haoxiang Sun, Hanwen Song
Summary: This paper presents a new decomposition mode for robot-world calibration, which decomposes the Ad(SE(3)) equation using Chasles' motion. A two-step method based on point set matching is proposed. The superiority of this method is verified through simulations and experiments.
MECHANISM AND MACHINE THEORY
(2024)
Article
Engineering, Mechanical
Yanlin Chen, Xianmin Zhang, Yanjiang Huang, Yanbin Wu, Jun Ota
Summary: This study establishes an error model for a 3-RRR+UR spherical parallel mechanism and analyzes the sensitivity of error parameters. A design structure is proposed to reduce input errors based on the analysis. Experimental results show that the multiloop circuit incremental method provides more accurate results.
MECHANISM AND MACHINE THEORY
(2024)
Article
Engineering, Mechanical
Vu Linh Nguyen, Chin-Hsing Kuo, Po Ting Lin
Summary: This paper presents a method for analyzing the performance of gravity-balanced serial robotic manipulators under dynamic loads and uses a three-degree-of-freedom planar serial manipulator as a case study. The significance of this method is demonstrated by evaluating the impact of dynamic loads on gravity-balanced performance and proposing a step-by-step design procedure to improve it.
MECHANISM AND MACHINE THEORY
(2024)
Article
Engineering, Mechanical
Shifeng Rong, Jiange Zhang, Xing Zhang, Keliang Li, Kaibin Rong, Zhenyu Zhou, Han Ding
Summary: This article proposes a data-driven dry cutting tool collaborative optimization model to improve the economic and environmental attributes of facehobbing hypoid gears. An innovative ease-off tooth contact analysis method is introduced to establish accurate relations between ease-off flank and loaded contact performance evaluations. The proposed model significantly improves sustainability in terms of economic and environmental assessments.
MECHANISM AND MACHINE THEORY
(2024)
Article
Engineering, Mechanical
Kemal Eren, Soley Ersoy, Ettore Pennestri
Summary: This research investigates the instantaneous kinematics of the terminal link of a planar two-link open chain using the complex-number technique and higher-order instantaneous invariants.
MECHANISM AND MACHINE THEORY
(2024)
Article
Engineering, Mechanical
Bo Han, Zhantu Yuan, Jiachuan Zhang, Yundou Xu, Jiantao Yao, Yongsheng Zhao
Summary: This paper proposes novel deployable mechanism units with self-limiting position function, and constructs ring truss deployable mechanisms. The degrees of freedom (DOF) of deployable units are analyzed and it is proved that the constructed ring truss deployable mechanisms have only one DOF. The dynamic model of the deployable mechanism unit with passive actuation is established and verified by simulation. The deployable mechanism units proposed in this paper have the advantages of good scalability and stability, and have broad application prospects.
MECHANISM AND MACHINE THEORY
(2024)