Article
Engineering, Mechanical
Carlos Pardo Garcia, Jhan Piero Rojas, Sofia Orjuela Abril
Summary: The study shows that applying surface texturing on the cylinder liner can reduce friction force and power loss, while increasing MOFT. The implementation of fully flooded lubrication boundary conditions may result in an overestimation of total friction force.
Article
Engineering, Mechanical
Swagatika Biswal, Prakash Chandra Mishra
Summary: Friction loss in an internal combustion engine is largely determined by elastohydrodynamic lubrication. The piston compression ring contributes to such losses in the piston subsystem. The complex elastodynamics of the ring affect the lubrication of the ring liner contact conjunction. Using finite difference technique, the study demonstrates a 23.53% reduction in friction power loss due to elastodynamic ring compared to rigid ring. Elastodynamic effect improves lubricant flow and sustainability of elastohydrodynamic lubrication depends on ring-liner elastodynamics.
Article
Engineering, Mechanical
M. Conradi, A. Kocijan, D. Klobcar, B. Podgornik
Summary: The study found that under different sliding conditions, dimples defined by nanosecond laser exhibited the lowest steady-state coefficient of friction, while in Hank's solution, lines and crosshatching showed better frictional characteristics after running-in and the removal of bulges around the laser textures. In terms of wear resistance, low-density lines pattern and particularly dimples were the most promising in contact situations likely to occur during starved/dry-lubrication conditions.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Acoustics
Lvjun Qing, Lichen Gu, Yan Wang, Wei Xue, Zhufeng Lei
Summary: A proposed elastohydrodynamic lubrication model is used to analyze the wear of key friction interfaces in piston pumps, specifically focusing on the leakage of the piston ring-cylinder bore interface (PRCB). The results show that the leakage of PRCB has a negative effect on the return oil flow of the pump case, and the leakage is proportional to the rotation speed while decreasing the return oil flow. The effects of rotation speed are enhanced under high discharge pressure conditions.
SHOCK AND VIBRATION
(2021)
Article
Materials Science, Coatings & Films
Pao-Chang Huang, Chih-Cheng Chou, Li-Shan Hsu
Summary: This study investigates the effect of electrodeposition parameters on Ni-W alloy coatings, determining optimal conditions for increased wear and friction resistance on piston rings. Results show that Ni-40.6 wt%W alloy exhibits improved mechanical and tribological properties compared to hard chromium coatings. The resistance of Ni-40.6 wt%W alloy coatings to wear and scratching on piston rings is confirmed through engine testing.
SURFACE & COATINGS TECHNOLOGY
(2021)
Article
Thermodynamics
A. Q. Almansoori, A. Hajialimohammadi, S. M. Agha Mirsalim, M. Mehrabivaghar
Summary: This study presents a multi-objective optimization and sensitivity analysis of a SI engine piston-rings pack using dynamics analysis software and optimizer software. The effects of changing the piston rings' tangential force and face profile on the oil and gas flow behavior were investigated, and the feasibility of the simulation model was determined by comparing it to experimental data. The results showed that modifying the tangential force can significantly reduce oil consumption and have a minimal impact on friction.
JOURNAL OF APPLIED FLUID MECHANICS
(2022)
Article
Thermodynamics
Di Hei, Meiru Zheng, Cheng Liu, Liutao Jiang, Yongfang Zhang, Xiaowei Zhao
Summary: To achieve maximum fuel economy of an engine, the study investigates the effect of different viscosity lubricants on the friction properties of the compression ring-cylinder liner conjunction. It is found that low viscosity lubricants facilitate the transition from starve to fully flooded lubrication conditions, but result in increased wear load on the compression ring surface while reducing friction power loss.
ADVANCES IN MECHANICAL ENGINEERING
(2023)
Article
Engineering, Mechanical
Parul Mishra, Ramkumar Penchaliah
Summary: Under different lubrication regimes, coated samples with texturing demonstrated better frictional performance compared to non-textured coated samples. The maximum friction reduction was observed for textured DLC coated samples under boundary lubrication regime. This behavior was proposed to be a result of the synergistic effect of graphitisation and texturing.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2021)
Article
Engineering, Mechanical
Lining Gao, Yi Cui, Zhaohui Xu, Yan Fu, Shuo Liu, Yafen Li, Xinrong Hou
Summary: This paper proposes a new method to achieve fully coupled modeling of the piston-ring-liner system from the perspective of multi-flexible-body dynamics. The study considers the contact characteristics of the ring groove and calculates the system boundary loads through the blow-by model. The effect of ring groove deformation on ring properties is revealed, and the complex tribo-dynamic behaviors of the system such as twisting and fluttering are characterized. After fully coupled modeling, piston deformation at the ring groove position can reach 65.80 μm, resulting in a 1.33 μm reduction in the minimum oil film thickness compared to the uncoupled model, and uneven ring wear is aggravated.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Mechanical
Rita Ferreira, Oscar Carvalho, Luis Sobral, Sandra Carvalho, Filipe Silva
Summary: The radial surface coating layer of compression piston rings is used to improve wear resistance in internal combustion engines. However, the friction coefficient of the piston ring-cylinder liner pair at top dead centers negatively affects the engine's tribological performance. This study tested dimples with different texture dimensions and densities in a home-developed tribometer and found that the texture with an aspect ratio of 0.25 and a density area of 15% yielded the best tribological results.
Article
Engineering, Electrical & Electronic
Tingkun Chen, Lin Wang, Jin Xu, Tianyu Gao, Xiuzhang Qin, Xiaobin Yang, Qian Cong, Jingfu Jin, Chaozong Liu
Summary: In this study, a double groove texture was designed on the surface of a piston ring to improve the sealing performance, which could reduce the deformation of the piston ring group and enhance the fuel economy and power performance of the engine.
Article
Engineering, Mechanical
Yixu Niu, Xianjuan Pang, Shiwei Yue, Bao Shangguan, Yongzhen Zhang
Summary: The study investigated the main factors influencing the friction and wear properties of steel surfaces under non-conformal contact in starved lubricated conditions, showing that the depth of dimples significantly affects these properties, with the best performance achieved for surfaces textured at a depth of 10 μm, an area density of 10%, and a diameter of 100 μm. Additionally, the friction coefficient exhibited distinct characteristics in different friction and wear stages, delineated as steady-state, variation-state, and dry-friction stages. Surfaces with optimal textured depths effectively prolonged the steady-state and reduced friction and wear during the variation-state, resulting in longer sliding distances in starved lubrication.
Article
Engineering, Mechanical
Lyu Xiuyi, Bowen Jiao, Xiqun Lu, Dequan Zou, Xuan Ma, Anne Neville
Summary: This study focuses on the simulation of lubrication performance of two-stroke marine engines, and establishes a model for tribofilm growth and wear, which is validated through experimental results. The simulation results reveal the significance of tribofilm in the lubrication performance of two-stroke marine engines.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Mechanical
Tongyang Li, Xiaotong Zhu, Huaguo Tang, Baofeng Zhang, Lujie Wang, Yuan Yu, Zhuhui Qiao, Xuan Ma
Summary: This study proposes a new method for determining the lubrication regime in the piston ring-cylinder liner tribosystem based on comparing oil film thickness with critical values using characteristic topo-graphic parameters. The method can classify the lubrication regime into hydrodynamic, micro-plasto-elastohydrodynamic, micro-plastohydrodynamic, thin film, boundary, or mixed lubrication. The influence of thermal effects and oil-feed conditions on the lubrication regime is also discussed.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Mechanical
Zhan Liu, Xianghui Meng, Limin Zhang, Weisheng Cheng, Xing Wang
Summary: It is found that ring dynamics significantly affect tribological performance, axial reversing movement of the piston ring is the main cause of gas pressure oscillation, and piston motion has a significant impact on ring dynamics.
JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME
(2022)
Article
Engineering, Mechanical
R. Gholami, Saleh Akbarzadeh, S. Ziaei-Rad, M. M. Khonsari
Summary: The study aims to investigate the impact of nano-particles' weight fraction on the friction coefficient in mixed-lubrication regime through experimental and theoretical analysis. Results demonstrate good agreement between theoretical and experimental findings, with a parametric study conducted to explore additional influencing factors.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2021)
Article
Engineering, Mechanical
Behnam Hajshirmohammadi, Michael M. Khonsari
Summary: An online approach using thermoelectricity was proposed to predict the fatigue life of metallic specimens under cyclic loading. The methodology was validated with experimental results, showing a practical methodology for early prediction of fatigue. The correlation between thermoelastic potential and fatigue life was demonstrated in low-carbon steel 1018 specimens measured via an infrared camera.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2021)
Article
Engineering, Mechanical
Arash P. Jirandehi, M. M. Khonsari
Summary: A statistical method is presented for estimating the plastic strain energy per cycle in metals under fatigue. The distribution of plastic strain under cyclic loading follows a two-parameter Weibull probability function and a second probability function is incorporated to account for different crystallographic directions. Results from a thermodynamically based model and a finite element model support the predictions made using the statistical method.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Engineering, Mechanical
A. Nourian-Avval, M. M. Khonsari
Summary: This paper proposes a model for predicting fatigue life under multiaxial loading based on dissipated heat during fatigue tests, evaluating fatigue damage by considering different rates of dissipated energy under various multiaxial loadings. The predictive capability of the models is confirmed through comparison with experimental fatigue results.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Engineering, Mechanical
M. Mehdizadeh, M. M. Khonsari
Summary: The study presented an experimental and theoretical analysis of low carbon steel 1018 subjected to multiaxial loading, showing that different loading conditions affect fatigue life. The use of thermography for fatigue life prediction was more accurate than hysteresis loops in capturing specimens' fatigue life under multiaxial fatigue loading.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Engineering, Mechanical
Joonyoung Jang, Michael M. Khonsari
Summary: A new nonlinear fatigue damage accumulation model is developed in this paper, which considers the loading sequence effect and predicts the rate of damage by introducing a loading sequence parameter. The applicability of the proposed model is validated using nine sets of independent experimental measurements of fatigue life under multiple loading sequences, showing that the predictions are in agreement with the measured results and providing a reliable estimation of fatigue life.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2021)
Review
Engineering, Mechanical
Arash P. Jirandehi, Michael M. Khonsari
Summary: Recent progress in microstructure-sensitive research has led to insights on estimating fatigue damage and predicting useful life. A computational crystal plasticity approach incorporating statistical representations of material microstructure and a new thermodynamically based framework has been suggested.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2021)
Article
Materials Science, Composites
Ali Mahmoudi, Michael M. Khonsari
Summary: A new approach utilizing the concepts of kinetic strength and fracture fatigue entropy can reliably predict the fatigue life of laminated composites by considering the temperature and time dependence through Zhurkov's model.
JOURNAL OF COMPOSITE MATERIALS
(2022)
Article
Engineering, Mechanical
Ali Mahmoudi, M. M. Khonsari
Summary: A new method based on the fracture fatigue entropy (FFE) criterion is proposed to predict the fatigue life of metals. This method utilizes the concept of kinetic strength of solid materials to rapidly predict the cyclic plastic strain energy and temperature evolution. Experimental results for Al 7075-T6, LCS 1018, API 5L X52, and MCS 1045 are compared with theoretical predictions, demonstrating that this model can reliably predict the temperature evolution, plastic strain energy dissipation, and fatigue life of metals.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Engineering, Mechanical
Arash P. Jirandehi, Ali Haghshenas, M. M. Khonsari
Summary: In this study, fully-reversed bending fatigue and impulse excitation tests were conducted to investigate the behavior of High Carbon Steel (HCS) at different environmental temperatures. It was found that with increasing environmental temperature, the specimens tended to become more brittle, leading to a decrease in fatigue life.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Engineering, Chemical
Soroosh Salehi, Sahar Ghatrehsamani, Saleh Akbarzadeh, M. M. Khonsari
Summary: This paper presents an experimental procedure and a thermodynamic methodology for evaluating adhesive wear in systems with variable and sequential speeds. The continuum damage mechanics (CDM) is used to estimate the probability of asperities forming wear particles and derive the wear coefficient. The results show that the wear coefficient in descending cases is higher than in ascending velocity experiments. Additionally, Archard's law is not suitable for predicting wear volume in situations with variable speeds.
Article
Physics, Multidisciplinary
Mohammad A. Amooie, K. P. Lijesh, Ali Mahmoudi, Elaheh Azizian-Farsani, Michael M. Khonsari
Summary: The effect of sudden variations in working modes and fatigue behavior of CS 1018 is studied using a general model based on the concept of fracture fatigue entropy (FFE). Fully reversed bending tests are conducted on dog bone specimens with variable frequency tests to simulate fluctuating working conditions. The results show that regardless of frequency changes, FFE remains constant and within a narrow band range, similar to a constant frequency.
Article
Engineering, Mechanical
Mohammad A. Amooie, M. M. Khonsari
Summary: This study investigates the fracture behavior of carbon steel 1018 in low-temperature environments. Fully-reversed bending experimental tests were performed to examine the efficacy of using Fracture Fatigue Entropy (FFE) concept for predicting fatigue life at different environmental temperatures. The results show that lower operating temperatures can improve fatigue life of carbon steel. Additionally, FFE remains nearly constant and can be used for reliable prediction of fatigue life at different environmental temperatures. Illustrative examples are provided to demonstrate the utility of this approach for prediction purposes.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Article
Mechanics
A. Mahmoudi, M. R. Khosravani, M. M. Khonsari, Tamara Reinicke
Summary: This study investigates the accumulated entropy at the crack tip of a semi-circular bending (SCB) specimen to determine the threshold for material fracture and interatomic debonding. The plastic flow at the crack tip is measured using the Digital Image Correlation (DIC) technique and strain maps superposed to SCB specimens. The generated entropy at the crack tip reaches a critical limit, beyond which bond breakage occurs, leading to crack surface propagation.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Materials Science, Multidisciplinary
Ali Mahmoudi, Mohammad A. Amooie, Lijesh Koottaparambil, Michael M. Khonsari
Summary: This study introduces a reliable technique for predicting the remaining useful life of components by measuring the temperature signature when the operating frequency is rapidly changed. The approach is validated through fatigue tests on stainless steel specimens. The method allows for predicting the remaining useful life at different operating frequencies.