Article
Dentistry, Oral Surgery & Medicine
Junghoon Lee, Sunil Kim, Euiseong Kim, Kyung-Ho Kim, Seong Taek Kim, Yoon Jeong Choi
Summary: This study evaluated the clinical performance of managing cracked teeth with reversible pulpitis through a combination of internal and external splinting. Bidirectional splinting successfully treated cracked teeth with reversible pulpitis, with pain on percussion being an important factor in deciding whether to attempt root canal treatment on symptomatic cracked teeth. A step-by-step approach with bidirectional crack splinting should be encouraged for cracked teeth with vital pulp without mechanical allodynia instead of preemptive root canal treatment.
INTERNATIONAL ENDODONTIC JOURNAL
(2021)
Article
Engineering, Mechanical
Xingkai Yang, Dongdong Wei, Ming J. Zuo, Zhigang Tian
Summary: This study focuses on the vibration characteristics of a spur gearbox with multiple tooth cracks and proposes a novel method using crack induced impulses (CII) for detecting the number and locations of the tooth cracks. The effectiveness of the proposed method is demonstrated using simulated and experimental gearbox vibration data.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Engineering, Mechanical
Yunfan Yang, Xinru Guo, Yu Sun, Liang Ling, Tao Zhang, Kaiyun Wang, Wanming Zhai
Summary: This study investigates the wheel/rail dynamic interactions of heavy-haul locomotives subjected to traction loads and different contact conditions using a non-Hertzian contact method. The results show that traction effort and friction conditions significantly influence the contact forces, distributions of contact stress, and wear index in the wheel/rail contact patch.
VEHICLE SYSTEM DYNAMICS
(2022)
Article
Engineering, Mechanical
Zaigang Chen, Yunsheng Zhi, Kaiyun Wang, Wanming Zhai
Summary: This study establishes a rigid-flexible locomotive coupled dynamics model of an HX locomotive and investigates the effects of the drive and transmission system on the wheel-rail dynamic response and wheel polygonal wear. The evolution of wear depth under different running speeds and wheel profile initial states is also studied.
VEHICLE SYSTEM DYNAMICS
(2023)
Article
Engineering, Mechanical
Jian Wu, Liang Ling, Kun Zhou, Kang Zhou, Ertian Zhang, Kaiyun Wang, Wanming Zhai
Summary: This paper investigates the formation mechanism and key influencing factors of middle coupler separation in heavy-haul trains through field investigation, theoretical analysis, and numerical simulation. The results indicate that the coupler separation typically occurs during the switching process of coupler force and is influenced by factors such as the initial height difference, braking force, and friction coefficient.
VEHICLE SYSTEM DYNAMICS
(2023)
Article
Engineering, Mechanical
Xingkai Yang, Ming J. Zuo, Zhigang Tian
Summary: Early diagnosis of gearbox tooth cracks is crucial for preventing catastrophic failures. A method was proposed to analyze crack induced impulses, and two new condition indicators were developed for tooth crack diagnosis, showing effectiveness in assessing crack severity.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Article
Engineering, Mechanical
Jiang Zhao, Lei Hou, Zhengminqing Li, Hong Zhang, Rupeng Zhu
Summary: The presence of root cracks in gears significantly impacts their dynamic performance by altering meshing stiffness and tribological characteristics, leading to changes in load distribution ratios and vibration.
ENGINEERING FAILURE ANALYSIS
(2022)
Article
Engineering, Mechanical
Zimeng Liu, Cheng Chang, Haodong Hu, Hui Ma, Kaigang Yuan, Xin Li, Xiaojian Zhao, Zhike Peng
Summary: Considering the calculation efficiency and accuracy of meshing characteristics of gear pair with tooth root crack fault, a parametric model of cracked spur gear is established by simplifying the crack propagation path. The LTCA method is used to calculate the time-varying meshing stiffness and transmission error, and the results are verified by finite element method. The study also proposes a crack area share index to measure the degree of crack fault and determines the application range of simplified crack propagation path.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Civil
Hongqin Liang, Pengfei Liu, Tianlong Wang, Haoyu Wang, Kailong Zhang, Yunqiang Cao, Dong An
Summary: This study investigates the wheel polygonal wear of a heavy-haul locomotive during a wheel repairing period through field testing. The results show that wheel polygon deterioration can affect locomotive traction performance, especially leading to obvious wheel-rail slipping and high tangential stress in wet rail conditions.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART F-JOURNAL OF RAIL AND RAPID TRANSIT
(2021)
Article
Engineering, Civil
Xin Ge, Liang Ling, Zaigang Chen, Jie Zhang, Kaiyun Wang, Wanming Zhai
Summary: This paper presents an experimental investigation on the dynamic performance of slave control locomotive couplers in 20,000-tonne heavy-haul trains and proposes a field test method for measuring and monitoring the dynamic behavior of heavy-haul locomotive couplers. The test results show that the front and rear couplers of the slave locomotive group respectively suffer the largest draw and buffing forces, and the maximum yaw angle appears at the middle coupler between the slave locomotives. The study also indicates that coupler instability generally occurs under train run in buffing forces, and the coupler status, track conditions, and duration of buffing forces have important effects on the coupler stability of slave control locomotives.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART F-JOURNAL OF RAIL AND RAPID TRANSIT
(2021)
Article
Engineering, Mechanical
Xin Ge, Liang Ling, Shiqian Chen, Qinghua Chen, Xuancheng Yuan, Yanlin Hu, Wanming Zhai, Kaiyun Wang
Summary: The derailment of locomotives in the turnout frog area is studied in this research. Through field investigation and numerical simulation, the derailment mechanism, influence factors, and methods to reduce the possibility of derailment are revealed.
VEHICLE SYSTEM DYNAMICS
(2023)
Article
Engineering, Mechanical
Yinghui Liu, Zhanqun Shi, Xiaoang Liu, Zhe Cheng, Dong Zhen, Fengshou Gu
Summary: In the gear transmission system, tooth root crack often occurs due to the impact of machining technology and cyclic load. The appearance of tooth root cracks will affect its mesh stiffness and change the vibration characteristics of the system, thereby reducing system reliability and service life. This study proposes an accurate mesh stiffness estimation model considering the opening crack and elastoplastic deflection of the cracked tooth.
ENGINEERING FAILURE ANALYSIS
(2022)
Article
Mechanics
Onur Can Kalay, Oguz Dogan, Celalettin Yuce, Fatih Karpat
Summary: A numerical method was developed to detect root crack damages in symmetric and asymmetric involute spur gears. Vibration signals were found to be more effective than Dynamic Transmission Error (DTE) in detecting tooth root cracks. The study also revealed that statistical indicator changes significantly increase with the increment of the drive side pressure angle, making fault detection easier.
MECHANICS BASED DESIGN OF STRUCTURES AND MACHINES
(2023)
Article
Engineering, Mechanical
Oguz Dogan, Celalettin Yuce, Fatih Karpat
Summary: Gears play a crucial role in power transmission systems, but are susceptible to high loads and impact forces, leading to surface cracks. By studying different rim thicknesses and pressure angles, the effects on fatigue crack propagation life and root stress were explored, resulting in a significant decrease in maximum stress values and a substantial increase in fatigue propagation life.
ENGINEERING FAILURE ANALYSIS
(2021)
Article
Engineering, Mechanical
Jieyu Ning, Zaigang Chen, Yunsheng Zhi, Xia Hua, Wanming Zhai
Summary: An improved method based on the theory of elastic mechanics for circular ring is proposed in this paper to accurately calculate the mesh stiffness of spur gears with tooth root crack. The calculated results are validated by the finite element method, and the effects of different parameters on the stiffness are investigated.
ENGINEERING FAILURE ANALYSIS
(2022)
Article
Engineering, Mechanical
Yuqing Liu, Zaigang Chen, Yifan Li, Wanming Zhai
Summary: This study establishes a skidding dynamics model of lubricated rolling bearings, considering the interactions between the roller and races, as well as the cage. The effects of lubricant stiffness, film thickness, friction coefficient, passing flow resistances, and resistance torques on the dynamic characteristics of the bearing are analyzed. The study also explores methods to mitigate skidding, such as adjusting roller number, lubricant properties, and interference fit. The results show that skidding is induced by low tangential friction forces and high passing flow resistances, and can be alleviated by strengthening interactions at the roller-race interface or reducing running resistance.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Engineering, Mechanical
Yuejian Chen, Gang Niu, Yifan Li, Yongbo Li
Summary: This study proposes an improved method for fault detection of railway suspension by modifying the BiLSTM neural network, which solves the problem of determining the noise level using monitoring data under faulty states. The experimental results demonstrate that the modified BiLSTM-based method outperforms other models in fault detection.
VEHICLE SYSTEM DYNAMICS
(2023)
Article
Engineering, Mechanical
Zaigang Chen, Yunsheng Zhi, Kaiyun Wang, Wanming Zhai
Summary: This study establishes a rigid-flexible locomotive coupled dynamics model of an HX locomotive and investigates the effects of the drive and transmission system on the wheel-rail dynamic response and wheel polygonal wear. The evolution of wear depth under different running speeds and wheel profile initial states is also studied.
VEHICLE SYSTEM DYNAMICS
(2023)
Article
Engineering, Mechanical
Yifan Li, Xin Zhang, Zaigang Chen, Yaocheng Yang, Changqing Geng, Ming J. Zuo
Summary: This paper proposes a novel time-frequency ridge estimation (TFRE) method, which integrates a new cost kernel function and an adaptive search region detection principle to improve the performance of ridge estimation. Experimental results demonstrate that the proposed TFRE outperforms state-of-the-art methods in ridge estimation.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Engineering, Multidisciplinary
JieYu Ning, ZaiGang Chen, WanMing Zhai
Summary: An improved mesh stiffness calculation method for helical gear with spatial crack is proposed in this study to consider the coupling effects between neighboring loaded teeth, improving the accuracy and applicability of the calculation. The load distribution law for the engaged cracked tooth along the tooth width and profile can be obtained. The results show that the mesh stiffness of the multi-tooth engagement calculation using this model can be further improved compared with traditional methods.
SCIENCE CHINA-TECHNOLOGICAL SCIENCES
(2023)
Article
Engineering, Mechanical
Kun Yue, Zhong Kang, Mengjie Zhang, Liming Wang, Yimin Shao, Zaigang Chen
Summary: An improved gear meshing power loss calculation method is proposed in this paper to consider the coupling effects between gear friction and dynamic characteristics. A six degrees-of-freedom gear dynamic model and power loss iteration calculation process are established, and the effects of gear surface quality and loads on power loss are analyzed. Experimental results show that this method is in better agreement with the experimental results compared to the traditional method.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Mechanical
Yuqing Liu, Zaigang Chen, Kaiyun Wang, Wanming Zhai
Summary: The gear transmission in high-speed trains is important for transmitting traction torque. Wheel-rail interactions can affect the gear transmission and support bearings on curves with larger centrifugal forces. To address this, a spatial vehicle-track coupled dynamics model is proposed, considering various factors such as time-varying mesh stiffness, dynamic transmission error, support stiffness, and internal interactions of the gearcase bearing. Results show that the lateral force and derailment coefficient are affected by the lateral component of the mesh force, and the centrifugal effect influences the contributions of the gear pair's lateral and vertical motions.
VEHICLE SYSTEM DYNAMICS
(2023)
Article
Engineering, Mechanical
Ke Feng, J. C. Ji, Qing Ni, Yifan Li, Wentao Mao, Libin Liu
Summary: Gearboxes are widely used in intelligent manufacturing systems and are prone to wear in harsh working environments. This paper presents a novel gear wear prognostic scheme using vibration analysis. It develops a new health indicator (HI) based on cyclic correntropy and Wasserstein distance to accurately evaluate gear wear severity. The optimized gated recurrent unit (GRU) network, with hyperparameters adaptively determined by genetic algorithm (GA), is applied to predict the remaining useful life (RUL) of the gear transmission system. The developed prognostic scheme effectively reveals gear wear characteristics and accurately predicts RUL.
Article
Automation & Control Systems
Yifan Li, Yaocheng Yang, Ke Feng, Ming J. J. Zuo, Zaigang Chen
Summary: This article proposes a new automated and adaptive ridge extraction method for accurately extracting the instantaneous frequency information of signal components from time-frequency graphs. It has the advantage of assessing machine health conditions without rotational speed measurement.
IEEE-ASME TRANSACTIONS ON MECHATRONICS
(2023)
Article
Engineering, Mechanical
Zirui Ye, Zaigang Chen, Ziwei Zhou, Wanming Zhai
Summary: This paper develops a dynamics model of a locomotive with direct drive traction system, taking into account the electromechanical coupling effect and nonlinearities in the wheel-rail contact and flexible transmission coupling. The results show that the harmonic components in the electrical subsystem have significant effects on the key components of the locomotive and can cause resonance in the mechanical transmission system at specific speeds. The resonance can be eliminated by adopting a harmonic suppression algorithm.
VEHICLE SYSTEM DYNAMICS
(2023)
Article
Engineering, Electrical & Electronic
Yifan Li, Ke Feng, Yuejian Chen, Zaigang Chen
Summary: In this article, a multioperator morphological undecimated wavelet (MOMUW) approach is proposed to effectively denoise and extract impulse features from vibration mixtures. Experimental results demonstrate that the proposed method can accurately detect wheelset bearing compound faults and outperforms the existing approaches. Moreover, the success and failure of MUWs with different operators and levels in bearing fault diagnosis are analyzed and compared, providing a theoretical foundation for constructing new MUWs.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2023)
Article
Engineering, Mechanical
Zaigang Chen, Jieyu Ning, Guojun Yang, Zhihui Chen, Jizhong Yang, Wanming Zhai
Summary: This study developed a dynamic model for the rack railway vehicle and track system to evaluate their dynamic behaviors on large-slope lines. The research found that the vibration responses of the wheelset and the rack are mainly influenced by the gear-rack mesh excitations, and the presence of gear-rack engagement reduces wheel loads.
VEHICLE SYSTEM DYNAMICS
(2023)
Article
Engineering, Mechanical
Willy Ank de Morais, Railson Bolsoni Falcao, Mario Boccalini Jr, Fernando Jose Gomes Landgraf
Summary: This study compares the fatigue behavior of bcc Nb-48 wt%Ti (Ti-36at%Nb) alloy parts processed by Laser Powder Bed Fusion (L-PBF) using two different types of powders (spherical powder produced by Plasma Atomization and irregularly shaped powder produced by Hydride-Dehydride). The results show that the fatigue behavior is similar for both powders, but the specimens produced from the Hydride-Dehydride powder have higher dispersed results. Fracture primarily occurs in the porosities near the machined sample surface, and the fatigue cracks propagate in a zigzag mode parallel to the L-PBF building direction.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Guoxi Jing, Shuai Sun, Teng Ma, Shubo Li, Tian Ma, Junchao Wei, Jianchao Pang
Summary: This study proposes a parameter identification method for predicting the TMF life of CGI materials used in cylinder heads. The study evaluates the TMF behavior of RuT450 material and successfully predicts its TMF life using multi-objective optimization. The results highlight the influence of plastic strain amplitude, temperature, and strain rate on the damage mechanism and life prediction.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Xin Zhang, Xu Li, Weipeng Xu, Kuidong Gao, Kao Jiang, Xinyu Wang, Hongxin Wei
Summary: Conical picks are commonly used in tunnel excavation and often experience high temperatures during the cutting process. This study investigated the influence of temperature on the wear of conical picks and proposed a method for measuring rock abrasiveness that takes into account the thermal effect. The experimental results showed that cooling liquid reduced the maximum temperature and the mean mass loss of the conical pick. Additionally, the study examined the characteristics of oxygen and found evidence of peeling, cracking, and oxidation on the grinding rod used for rock abrasiveness measurement.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Vivek Srivastava, Deependra Singh, A. G. Rao, V. P. Deshmukh
Summary: Engine gear failures are a significant concern in various industries. Investigating each gear failure and determining the root cause is important for preventing future failures. This study used experimental and numerical analysis techniques to investigate the premature failure of a flywheel gear in a marine diesel engine. The findings revealed that the gear failed due to overload stresses caused by overload torque generated from sudden inertial thrust in the internal combustionengine.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Jun Zhang, Weidong Liu, Feilong Liu, Zhiqiang Yang, Jinfang Peng, Minhao Zhu
Summary: During a major overhaul of an aeroengine, a cracked stator vane of the low-pressure compressor was discovered, with the crack originating from a corrosion pit located on the arc transition between the leading edge and the upper edge plate. The fracture surface exhibited signs of fatigue cracks, indicating a pit-related fatigue crack. Metallographic examination revealed that most corrosion pits were distributed beneath the bulging or peeling paint layer on the leading edge and the concave side. Identification of the corrosion products showed the presence of sulfate and alumina, suggesting atmospheric corrosion as a likely cause for the cracked stator vane.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Juan Jose Jimenez de Cisneros Fonfria, Ester Olmeda, Susana Sanz, Maria Garrosa, Vicente Diaz
Summary: Energy absorbing devices in vehicles can partially transform impact energy and protect passengers. In this paper, the failure analysis of the underframe crumple zone in a train car was conducted through finite element simulations, showing that the component acted properly after the impact.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Fengqi Zhang, Gang Luo, Haiyang Zhang, Peihong Cong, Lulu Liu, Wei Chen
Summary: In this study, a predictive model for bird strike trajectory was developed based on the quasi-linear viscoelastic model. By combining simulation analysis under multiple conditions, the model reproduced the trajectory change law in low and medium speed bird impact experiments.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
S. M. de Gouveia, L. de Abreu Correa, D. B. Teles, M. Oliveira, T. G. R. Clarke
Summary: Emergency Shutdown Valves (EDSVs) are used in industrial applications to interrupt fluid flow during hazardous events. The damage to the valve seats can be detected by analyzing the pressure and torque data. This study compared three processing options and found that evaluating the complete signature with a Gradient Boosting Classifier algorithm is the most effective strategy.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Xinyan Jin, Kai Wang, Hongwei Qian
Summary: This study investigated the root cause of an abnormal premature groove-clogging failure on a sink roll in a hot-dip galvanizing line. It was found that the failure was caused by the buildup of a large amount of Fe2Al5Znx dross in the grooves, and the key factor was the control of Tstrip.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Zhiqiang Li, Jie Li, Cen Li, Xiaodong Xie, Zhiyong Yang
Summary: In this study, the microstructure evolution of the material in the hot spot area of the high-speed train brake disc was observed and the mechanism of mechanical property degradation was obtained through tensile tests. The research results provide guidance for crack damage identification of the brake disc and condition-based maintenance.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Lijia Luo, Yincheng Wang, Wei Chen, Zuming Zhao, Wenfei Chen, Shiyi Bao
Summary: Tube-to-tube impact wear is a significant factor in the failure of alloy 690 tubes in nuclear steam generators. This paper investigates the wear damage mechanism and detection method of alloy 690 tubes under tube-to-tube impact loads. The results reveal the wear damage mechanism through analysis of macro and micro morphologies as well as metallographic structures. A nonlinear ultrasonic wave mixing method is proposed for damage detection and a detection device is developed to implement this method. Experimental results indicate that the damage mode of tube-to-tube impact wear varies with impact load and cycle number, and the nonlinear modulation index is effective in assessing the damage degree of alloy 690 tubes.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Xing-Ju Yang, Feng Lin, Xu Du, Lu Qiu
Summary: This paper proposes a novel method of improving the progressive collapse resistance of RC frame structures by adding locally debonded kinked steel plates (KPs). Experimental tests and finite element analysis reveal that the addition of KPs significantly enhances the ultimate resistance and deformability of the beam-slab substructures. The mechanism of resistance improvement is explained, and an analytical model is developed for predicting the ultimate resistance of the structures.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Xiaohe Wang, Zengqiang Cao
Summary: This paper presents a dynamic installation (DI) method based on electromagnetic force to reduce damage to composite laminates and improve joint performance. The study shows that DI can effectively decrease installation resistance, reduce severe damage to laminates, and improve stress distribution in the joint.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Jitong Cui, Yingying Kong, Cuiwei Liu, Baoping Cai, Faisal Khan, Yuxing Li
Summary: This paper presents a method for quantifying the failure probability of hydrogen doped pipelines and utilizes Bayesian network for quantitative calculation. The results show that this method can more accurately assess the failure probability of hydrogen doped pipelines and provide a decision basis for preventing failure accidents.
ENGINEERING FAILURE ANALYSIS
(2024)
Article
Engineering, Mechanical
Yiping Jiang, Maoru Chi, Jungang Yang, Liangcheng Dai, Yuchen Xie, Zhaotuan Guo
Summary: This article investigates and simulates the derailment of empty freight trains at the switch section of a turnout in the diverging route, and proposes preventive measures. The results show that the derailment is caused by the combined effect of various factors, and reducing the longitudinal coupler force and the wheel rail friction coefficient can decrease the possibility of derailment. Additionally, installing a guard rail in front of the turnout can effectively prevent derailment.
ENGINEERING FAILURE ANALYSIS
(2024)
