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Effect of Surface Adhesion on the Rough Contact Response Near Complete Contact 接近完全接触时表面附着对粗接触响应的影响
IF 0.7 4区 工程技术
Mechanika Pub Date : 2022-08-30 DOI: 10.5755/j02.mech.28978
Siyuan Zhang, Yanwei Liu
{"title":"Effect of Surface Adhesion on the Rough Contact Response Near Complete Contact","authors":"Siyuan Zhang, Yanwei Liu","doi":"10.5755/j02.mech.28978","DOIUrl":"https://doi.org/10.5755/j02.mech.28978","url":null,"abstract":"The adhesion phenomena between interfaces is widely investigated in engineering and scientific research. Due to the complexity of loading condition and surface topography, the traditional adhesive theory has many limitations. To better understand the adhesive properties of rough surfaces, we release the restrictions of JKR theory and propose a new adhesive model for single asperity. Initiated by this, a discrete rough surface contact model is presented, which extends the application scope of the traditional theory. First, we establish an elastic model by describing the gap between the interfaces accurately, so analytical solutions which are still valid for high contact pressure are proposed. Then, based on this, the exact adhesive solutions for different shapes of indenters are derived, which greatly improves the predicting accuracy of contact relationship and adhesion force. Finally, we use the results in the analysis of rough surface. The effect of both surface roughness and surface energy on the adhesive response of rough contact are studied in detail. The results show that adhesion is more easily to happen for smooth and geometrically continuous surfaces. The overall adhesion effect will be reduced in rough surface analysis with the increasing of surface roughness and the decreasing of surface energy. Our research sheds light on the understanding of the adhesion between solids and provides a theoretical guidance for the design of adhesion biomimetic materials and MEMS systems.","PeriodicalId":54741,"journal":{"name":"Mechanika","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46401385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Multiscale Analysis of the Performance of Micro/nano Porous Filtration Membranes with Double Concentric Cylindrical Pores: Part II-Optimization Results 双同心圆柱孔微纳多孔过滤膜性能的多尺度分析:第二部分-优化结果
IF 0.7 4区 工程技术
Mechanika Pub Date : 2022-06-21 DOI: 10.5755/j02.mech.30509
Zhipeng Tang, Yongbin Zhang
{"title":"Multiscale Analysis of the Performance of Micro/nano Porous Filtration Membranes with Double Concentric Cylindrical Pores: Part II-Optimization Results","authors":"Zhipeng Tang, Yongbin Zhang","doi":"10.5755/j02.mech.30509","DOIUrl":"https://doi.org/10.5755/j02.mech.30509","url":null,"abstract":"The multiscale calculation results for the values of the optimized parameters are presented for the micro/nano porous filtration membranes with double concentric cylindrical pores where multiscale flows occur. For a weak liquid-pore wall interaction, the optimum ratio of the radius of the bigger pore to the radius of the smaller pore (i.e. the filtration pore) can be calculated from the classical equation, however the corresponding lowest flow resistance of the membrane should still be calculated from the multiscale analysis owing to the adsorbed layer effect when the ratio Landax of the thickness of the adsorbed layer to the radius of the smaller pore is greater than 0.1. For medium and strong liquid-pore wall interactions, the optimum ratios of the pore radii should be calculated from the multiscale analysis, and the corresponding lowest flow resistances of the membrane are much higher than the classical calculation showing the significant effect of the adsorbed layer when Landax>=0.1.","PeriodicalId":54741,"journal":{"name":"Mechanika","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46947128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Numerical Modelling of Emission Characteristic for a Single Cylinder Spark Ignition Engine 单缸火花点火发动机排放特性的数值模拟
IF 0.7 4区 工程技术
Mechanika Pub Date : 2022-06-21 DOI: 10.5755/j02.mech.31064
Brahim Menacer, Naima Khatir, M. Bouchetara
{"title":"Numerical Modelling of Emission Characteristic for a Single Cylinder Spark Ignition Engine","authors":"Brahim Menacer, Naima Khatir, M. Bouchetara","doi":"10.5755/j02.mech.31064","DOIUrl":"https://doi.org/10.5755/j02.mech.31064","url":null,"abstract":"The main objective of this study is to elaborate an engine cycle simulation program using GT-Suite software to analyze the influence of equivalence ration and compression ratio on the main emissions of a four-stroke direct injection spark ignition engine. The experimental result is used to compare the cylinder pressure result obtained with the developed model. The present article is a study of the effect of compression ratio and equivalence ratio on the main emissions of the direct injection spark engine for a two-zone combustion analytical model and by using of the GT-Suite simulation software. The developed analytical model is validated by the use of experimental data. The analytical curve of the pressure in the combustion chamber is experimentally validated with a difference of the order of 6%.","PeriodicalId":54741,"journal":{"name":"Mechanika","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44446163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Computational Evaluation of the Effect of Plunger Spring Stiffness On Opening and Closing Times of the Low-Pressure Gas-Phase Injector 柱塞弹簧刚度对低压气相喷射器启闭次数影响的计算评价
IF 0.7 4区 工程技术
Mechanika Pub Date : 2022-06-21 DOI: 10.5755/j02.mech.31230
D. Szpica, Michal Kusznier
{"title":"Computational Evaluation of the Effect of Plunger Spring Stiffness On Opening and Closing Times of the Low-Pressure Gas-Phase Injector","authors":"D. Szpica, Michal Kusznier","doi":"10.5755/j02.mech.31230","DOIUrl":"https://doi.org/10.5755/j02.mech.31230","url":null,"abstract":"In the paper, an attempt was made to computationally demonstrate the effect of the plunger pressure stiffness on the opening and closing times of the low-pressure gas-phase injector as a filling of the research gap in this subject.  Based on the presented mathematical model describing the operation of the injector, firstly the results were related to the manufacturer's technical data showing a shorter time to full opening by 2.77% and a longer time to full closing by 0.50%. On this basis, it was considered that the proposed model can be used for comparison purposes. In the assumed range of compression spring stiffness (100... 2000) N/m, it was shown that as the stiffness increases, the time to fully open decreases by 18.85%, while the time to fully closed decreases by 80.17%. Additionally, it is shown that the time-cross section as the stiffness of the compression spring increases can decrease up to 35.21% from the initial value. The obtained results can be useful in modeling the operation of an internal combustion engine or in the operational assessment of the gas injector condition.","PeriodicalId":54741,"journal":{"name":"Mechanika","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43157010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
A Battery-free Pressure Sensing System Based on Soft Piezoelectric Device for Tennis Training 基于软压电装置的无电池网球训练压力传感系统
IF 0.7 4区 工程技术
Mechanika Pub Date : 2022-06-21 DOI: 10.5755/j02.mech.30459
K. Yu, Yingxiang Gong, Zhifang Fan
{"title":"A Battery-free Pressure Sensing System Based on Soft Piezoelectric Device for Tennis Training","authors":"K. Yu, Yingxiang Gong, Zhifang Fan","doi":"10.5755/j02.mech.30459","DOIUrl":"https://doi.org/10.5755/j02.mech.30459","url":null,"abstract":"In this work, a battery-free position and pressure monitoring system based on soft polyvinylidene fluoride (PVDF) piezoelectric thin film with helical coils circuit design is designed and used for tennis training. The racket surface is firstly divided into block areas and the sensing transducers are placed in each of them to detect the hitting position and force in these areas. To modify the extensibility of the system for tennis training, all the devices are connected by the S-shape helical line, which has two states: curled at usual and straight at work. Four piezoelectric patches form a series system to power the energy harvest system and wireless communication module, which help to realize the battery-free and wearable functions. A linear relation between the hitting force and induced electric voltage is experiment verified with the slope of 0.05 V/N. The system is also verified in the real tennis ball game monitoring for the hitting time and hitting position, benefiting the future application of wearable devices in artificial intelligence and the Internet of Things (IoT).","PeriodicalId":54741,"journal":{"name":"Mechanika","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46917148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Multiscale Analysis of the Performance of Micro/nano Porous Filtration Membranes with Double Concentric Cylindrical Pores: Part I-Analysis Development 双同心圆柱孔微纳多孔过滤膜性能的多尺度分析:第一部分-分析进展
IF 0.7 4区 工程技术
Mechanika Pub Date : 2022-06-21 DOI: 10.5755/j02.mech.30507
Zhipeng Tang, Yongbin Zhang
{"title":"Multiscale Analysis of the Performance of Micro/nano Porous Filtration Membranes with Double Concentric Cylindrical Pores: Part I-Analysis Development","authors":"Zhipeng Tang, Yongbin Zhang","doi":"10.5755/j02.mech.30507","DOIUrl":"https://doi.org/10.5755/j02.mech.30507","url":null,"abstract":"In nanoporous filtration membranes, when the radius of the filtration pore is so big that the flow of the adsorbed layer on the pore wall is comparable with the flow of the continuum fluid in the central region of the pore, the multiscale analysis is required for estimating the performance of the membranes. The present paper presents such a multiscale analysis for the performance of nanoporous filtration membranes with double concentric cylindrical pores. The dimensionless flow resistance of the membrane was calculated for a weak fluid-pore wall interaction for varying operational parameter values. It was found that there is the optimum ratio of the radius of the filtration pore to the radius of the other bigger pore for the highest flux of the membrane.","PeriodicalId":54741,"journal":{"name":"Mechanika","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45798590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Investigation of the Effect of Cutting Directions On the Improvement of Mechanical Parameters of Treated Cork by THT: Experimental Measurement, Modelling and Optimization of Mass Transfer 切割方向对THT处理后软木材料力学参数改善的影响研究:传质实验测量、建模与优化
IF 0.7 4区 工程技术
Mechanika Pub Date : 2022-06-21 DOI: 10.5755/j02.mech.26956
Abdelkrim Zemirline, T. Kermezli, M. Announ, M. Douani
{"title":"Investigation of the Effect of Cutting Directions On the Improvement of Mechanical Parameters of Treated Cork by THT: Experimental Measurement, Modelling and Optimization of Mass Transfer","authors":"Abdelkrim Zemirline, T. Kermezli, M. Announ, M. Douani","doi":"10.5755/j02.mech.26956","DOIUrl":"https://doi.org/10.5755/j02.mech.26956","url":null,"abstract":"This work aims to investigate the impact of the cutting direction on the transfer properties of both the native cork and the treated by an optimized cycle at high temperature and boiling for the purpose to improve its mechanical characteristics in all three orthotropic directions. The study of the insulation performance is based on tracking the apparent mass diffusion coefficient (Dapp) variation in order to evolve a new material with the thermal, mass, acoustic and vibratory properties needed for various applications. TGA, IR and SEM analyzes are used to confirm the enhancement of the treated cork. The Dapp of the diffusing chemical species, NaCl (0.7M), is determined by conductimetric method. In transient mode, a mathematical model of mass transfer, which includes the diffusion parameters of the chemical species, is developed. Through the calibration of the model with the experimental measurements the Dapp values ​​were determined and then refined numerically by optimization using the Bat-Algorithm. The obtained results showed that the treatment improves the diffusion property of the native (DN) compared to the treaty (DA) with the values in the order of 10-12 and 10-13 m2.s-1 respectively with a relative uncertainty of 10-7. In addition, this investigation reveals that the radial diffusion coefficient (DR) is significantly higher than the tangential diffusion (DT) and longitudinal (DL) diffusion coefficients which both are almost of the same.","PeriodicalId":54741,"journal":{"name":"Mechanika","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44885831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Impacts of Length Scale Parameter on Material Dependent Thermoelastic Damping in Micro/nanoplates Applying Modified Coupled Stress Theory 基于修正耦合应力理论的长度尺度参数对微纳板材料热弹性阻尼的影响
IF 0.7 4区 工程技术
Mechanika Pub Date : 2022-06-21 DOI: 10.5755/j02.mech.25841
R. R., V. Babu, M. Baiju
{"title":"Impacts of Length Scale Parameter on Material Dependent Thermoelastic Damping in Micro/nanoplates Applying Modified Coupled Stress Theory","authors":"R. R., V. Babu, M. Baiju","doi":"10.5755/j02.mech.25841","DOIUrl":"https://doi.org/10.5755/j02.mech.25841","url":null,"abstract":"Among the different energy dissipation mechanisms, thermoelastic damping plays a vital role and need tobe alleviated in resonators inorder to enhance its performance parameters by improving its thermoelastic dampinglimited qualityfactor, QTED. The maximum energy dissipation is also interrelated with critical length (???????? ) of theplates and by optimizing the dimensions the peaking of energy dissipation can be diminished. As the size of thedevices is scaled down, classical continuum theories are not able to explain the size effect related mechanicalbehavior at micron or submicron levels and as a result non-classical continuum theories are pioneered with theinception of internal length scale parameters. In this paper, analysis of isotropic rectangular micro-plates based onKirchhoff model applying Modified Coupled Stress Theory is used toanalyzethe size-dependent thermoelasticdamping and its impact on quality factor and critical dimensions.Hamilton principle is adapted to derive thegoverning equations of motion and the coupled heat conduction equation is employed to formulate the thermoelasticdamping limited quality factor of the plates. Five different structural materials (PolySi, Diamond,Si, GaAs andSiC)are used for optimizing QTED which depends on the materialperformance index parameters. ThermoelasticDamping Index [TDI] and thermal diffusion length, lT. According to this work, the maximum QTED is attained forPolySi with the lowest TDI and Lcmax is obtained for SiC which is having the lowest lT. The impact of lengthscaleparameters (l), vibration modes, boundary conditions (Clamped–Clamped and Simply Supported), and operatingtemperatures on QTED and Lcare also investigated. It is concluded that QTED is further maximized by selecting lowtemperatures and higher internal length scale parameters (l).The prior knowledge of QTED and Lchelp the designers tocome out with high performance low loss resonators.","PeriodicalId":54741,"journal":{"name":"Mechanika","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45455597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Ballistic and Aerodynamic Characteristics Simulation for Trajectory Correction Projectile 弹道修正弹的弹道和气动特性仿真
IF 0.7 4区 工程技术
Mechanika Pub Date : 2022-06-21 DOI: 10.5755/j02.mech.31431
F. Dong, Yongjie Xu, Nana Zheng
{"title":"Ballistic and Aerodynamic Characteristics Simulation for Trajectory Correction Projectile","authors":"F. Dong, Yongjie Xu, Nana Zheng","doi":"10.5755/j02.mech.31431","DOIUrl":"https://doi.org/10.5755/j02.mech.31431","url":null,"abstract":"Conventional ammunition easily deviates from the intended target. Its hit probability is reduced by such disturbance factors as fabrication errors, initial muzzle disturbance, initial velocity probable error, and stochastic wind effect. The effect of the above interference factors can be reduced by improving the shooting dispersion, ammunition, and gun or rocket engine structure. However, such improvements may fail to meet the operational requirements for modern warfare. Ballistic correction technique is a proposed trajectory control technique for precision strike with effective damage. Taking a 57mm calibre projectile as research object, trajectory correction projectile with different aerodynamic layouts were designed. The aerodynamic characteristic, static stability, exterior ballistic characteristic and firing density of each projectile has been studied through research method of theoretical analysis and numerical calculation. These findings are considered instrumental in the trajectory correction technology research and engineering application.","PeriodicalId":54741,"journal":{"name":"Mechanika","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47313501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Vibration Energy Harvester (VEH) for a Free Body Moving in Space at Vibro Shock Mode 振动冲击模式下自由体空间运动的振动能量采集器
IF 0.7 4区 工程技术
Mechanika Pub Date : 2022-06-21 DOI: 10.5755/j02.mech.31034
R. Gaidys, Egidijus Stasytis, V. Daniulaitis, B. Narijauskaite
{"title":"Vibration Energy Harvester (VEH) for a Free Body Moving in Space at Vibro Shock Mode","authors":"R. Gaidys, Egidijus Stasytis, V. Daniulaitis, B. Narijauskaite","doi":"10.5755/j02.mech.31034","DOIUrl":"https://doi.org/10.5755/j02.mech.31034","url":null,"abstract":"The type of the generator was chosen to be piezoelectric because it is most widely used to capture the energy of mechanical vibrations and convert it into electricity. A 2D generator model was chosen for the analysis of the dynamics of the energy harvester (VEH) for a free body moving in space at vibro shock mode. The computational schemes of the model are presented. A mathematical model describing the dynamics is developed: generator casing, inertial mass, nonlinear contact/impact. The mathematical model is implemented by the Runge-Kutta numerical method in the Matlab system. Analysis of experimental and modeling results is performed: comparison of generator eigen frequencies, the logarithmic decrement and the damping coefficient – the error is in range of 5%. This generator can be used to collect mechanical energy of water waves, wind, human movements, and other environmental factors in the presence of the body's free movement trajectory in space.","PeriodicalId":54741,"journal":{"name":"Mechanika","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44259445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
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