Mechanika最新文献_第9页

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":null,"pages":null},"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

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

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

引用次数: 2

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

引用次数: 1

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

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":null,"pages":null},"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":null,"pages":null},"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

引用次数: 0

Study on the Fatigue of a Spherical Bearing Under Different Loading Conditions Considering Rotation Effect 考虑旋转效应的不同载荷条件下球面轴承疲劳研究

IF 0.7 4区工程技术

Mechanika Pub Date : 2022-06-21 DOI: 10.5755/j02.mech.31433

Yadi Fu, Hangyu Wang, Yanqing Fu

{"title":"Study on the Fatigue of a Spherical Bearing Under Different Loading Conditions Considering Rotation Effect","authors":"Yadi Fu, Hangyu Wang, Yanqing Fu","doi":"10.5755/j02.mech.31433","DOIUrl":"https://doi.org/10.5755/j02.mech.31433","url":null,"abstract":"In order to study the fatigue life of a large spherical bearing under actual working conditions, the finite element software ABAQUS was firstly used to establish the spherical bearing model and simulate the mechanical properties of the bearing at different rotation angles under four working conditions of pressure, tension, pressure shear, and tension shear. And the stress characteristics under the corresponding working conditions were obtained. On this basis, the stress results were imported into the fatigue analysis software, and the fatigue life of each component of the spherical bearing was calculated under the four working conditions. The results show that: the rotation angle of the upper bearing plate has obvious influence on the maximum stress of the bearing under various working conditions. The maximum stress is 554.5 MPa and locates in the wedge-shaped region of the lower bearing plate under the working condition of the joint action of tension and X-direction shear force, and when the rotation angle of the upper bearing plate is 1°. In other working conditions, the maximum stress of the bearing mostly occurs in the wedge-shaped position of the upper and lower bearing plates. The influence of the rotation angle of the upper bearing plate on the minimum fatigue life of the bearing shows the same trend as the influence on the maximum stress. The minimum fatigue life is 13,000 times and locates in the wedge-shaped region of the lower bearing plate under the working condition of the joint action of tension and X-direction shear force, and when the rotation angle of the upper bearing plate is 1°. In other working conditions, the lowest fatigue life of the bearing is also mostly found in the wedge-shaped area of the upper and lower bearing plates. So, the wedge-shaped area should be strengthened in the design.","PeriodicalId":54741,"journal":{"name":"Mechanika","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44807549","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