Mechanika最新文献_第6页

Obtaining The Fracture Resistance Curve Using The General Displacement 用一般位移求断裂阻力曲线

IF 0.7 4区工程技术

Mechanika Pub Date : 2023-02-06 DOI: 10.5755/j02.mech.31368

Goksel Saracoglu

引用次数: 0

Research on intelligent formation operation performance of straddle-type rapid transit vehicles in heterogeneous operating environment 跨座式快速交通车辆在异构运行环境下的智能编队运行性能研究

IF 0.7 4区工程技术

Mechanika Pub Date : 2023-02-06 DOI: 10.5755/j02.mech.32110

Zixue Du, Haoxin Wu, Zhen Yang, X. Wen

{"title":"Research on intelligent formation operation performance of straddle-type rapid transit vehicles in heterogeneous operating environment","authors":"Zixue Du, Haoxin Wu, Zhen Yang, X. Wen","doi":"10.5755/j02.mech.32110","DOIUrl":"https://doi.org/10.5755/j02.mech.32110","url":null,"abstract":"This paper presents an intelligent formation operation mode (IFOM) based on straddle-type rapid transit vehicles. Taking the straddle-type rapid transit vehicles operating in IFOM as the object, the operation mode of the vehicle is defined in the control system architecture of the straddle-type rapid transit system. In addition, considering the heterogeneous operating environ-ment of formation vehicles, an evaluation index system for formation vehicles is proposed. Then, according to the vehicle longitudinal dynamics model and the artificial potential field formation algorithm, we build the formation vehicle operation controller. After that, referring to the vehicle dynamics model, a multi rigid body dynamics simulation model of formation vehicles in a heterogeneous operating environment is established. Finally, the operating performance of formation vehicles in heterogeneous operating environment is analyzed. The analysis results show that the operation performance of the formation vehicle meets the requirements of the evaluation index system, which proves the feasibility of the formation operation of straddle-type rapid transit vehicles operating in IFOM.","PeriodicalId":54741,"journal":{"name":"Mechanika","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48351413","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 single point heating tool for the robotised incremen-tal polymer sheet forming process 单点加热工具在聚合物片材自动成型中的应用研究

IF 0.7 4区工程技术

Mechanika Pub Date : 2023-02-06 DOI: 10.5755/j02.mech.31366

D. Eidukynas, Baltramiejus Andrijaitis, V. Jūrėnas

引用次数: 0

Electro-Hydraulic Load-Sensitive Simulation Study of Walking Hy-draulic System of Electric Agricultural Machinery 电动农机行走液压系统的电液负载敏感仿真研究

IF 0.7 4区工程技术

Mechanika Pub Date : 2022-12-05 DOI: 10.5755/j02.mech.31470

Hongyun Mu, Y. Luo, Yu-gong Luo

{"title":"Electro-Hydraulic Load-Sensitive Simulation Study of Walking Hy-draulic System of Electric Agricultural Machinery","authors":"Hongyun Mu, Y. Luo, Yu-gong Luo","doi":"10.5755/j02.mech.31470","DOIUrl":"https://doi.org/10.5755/j02.mech.31470","url":null,"abstract":"The conventional load-sensitive hydraulic drive chassis system for agricultural machinery uses a combination of engine and load-sensitive pump, which cannot adjust the control strategy according to the working conditions. It does not meet the current trend of energy-saving and emission reduction. To this end, an electro-hydraulic load-sensitive hydraulic drive chassis system for agricultural machinery, which uses a combination of permanent magnet synchronous motor and quantitative pump, is proposed. A variable LS differential pressure control and a variable differential pressure control of the pressure compensation valve to improve agricultural machinery's working performance are proposed. AMESim is used to establish the system simulation model to obtain the system composite motion, variable LS differential pressure control, and variable pressure differential control of the pressure compensation valve performance. The simulation results show that the system achieves the essential functions of a conventional load-sensitive system. The variable LS differential pressure control and the variable pressure differential control of the pressure compensation valve are feasible. They can effectively improve the performance of agricultural machinery to adapt to working conditions. It can effectively reduce the system energy consumption and provide a theoretical basis for the intellectualization of electric agricultural machinery.","PeriodicalId":54741,"journal":{"name":"Mechanika","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47341326","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

Comparative Analysis of Temperature Field and Stress Field of TC4 Ti-tanium Alloy Joint Between CMT and MIG Welding CMT焊与MIG焊TC4钛合金接头温度场与应力场对比分析

IF 0.7 4区工程技术

Mechanika Pub Date : 2022-12-05 DOI: 10.5755/j02.mech.31491

Rui Zhang, X. Gu, Yuxian Meng, Lijuan Zhu

{"title":"Comparative Analysis of Temperature Field and Stress Field of TC4 Ti-tanium Alloy Joint Between CMT and MIG Welding","authors":"Rui Zhang, X. Gu, Yuxian Meng, Lijuan Zhu","doi":"10.5755/j02.mech.31491","DOIUrl":"https://doi.org/10.5755/j02.mech.31491","url":null,"abstract":"A model was used for the cold metal transfer (CMT) welding based on the volume heat flux distribution of double ellipsoids loaded with time intervals. The temperature field and stress field of TC4 titanium alloy were numerically simulated by ANSYS software. The distribution laws of temperature, residual stress and post-weld deformation during CMT and MIG welding were studied and compared. It was found that the maximum temperature of the molten pool in CMT welding was fluctuating and rising during the loading process, while the temperature of the molten pool in MIG welding was rising smoothly and the maximum temperature was higher than that in CMT welding. The welding stress field was analyzed by thermal-stress coupling analysis. The stress distribution simulated based on the MIG welding heat source was similar to CMT welding, but the maximum von Mises stress was greater than that of CMT welding. Due to the cooling shrinkage, both of them would produce angular deformation after welding. And the maximum angular deformation simulated based on the MIG welding heat source was greater than that of CMT welding. It was proved by welding simulation that CMT welding could reduce welding heat input and residual stress and deformation after welding.","PeriodicalId":54741,"journal":{"name":"Mechanika","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43089342","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

Damage Model of Bridge Bearing and Its Influence on Train-Track-Bridge Dynamic System 桥梁轴承损伤模型及其对列车-轨道-桥梁动力系统的影响

IF 0.7 4区工程技术

Mechanika Pub Date : 2022-12-05 DOI: 10.5755/j02.mech.30995

Xinmeng Ke, Fusheng Li, Zhaowei Chen

{"title":"Damage Model of Bridge Bearing and Its Influence on Train-Track-Bridge Dynamic System","authors":"Xinmeng Ke, Fusheng Li, Zhaowei Chen","doi":"10.5755/j02.mech.30995","DOIUrl":"https://doi.org/10.5755/j02.mech.30995","url":null,"abstract":"Bridge bearing damage is unavoidable in railway engineering. This work presents an investigation on the damage model of bridge bearing and its influence on the dynamic responses of the high-speed train-track-bridge system. Primarily, the mathematical description of bridge bearing damage model is explained in detail, which is then compared with the traditional linear model. Then a 3D train-track-bridge dynamic model considering bearing damage is established based on the train-track-bridge dynamic interaction theory. Adopting the model, the influences of single-point-damage and multi-point-damage on the dynamic behaviors of the coupled system are deeply investigated. Results show that the calculated obtained by the proposed model and the traditional linear model are different, especially in frequency-domain. Compared to results of traditional linear model, the results obtained by the proposed model are smaller due to the additional damping effect. Bridge bearing damage has almost no influence on the train vibrations, while has great effect on bridge vibrations. The damage in z-direction mainly affects the vertical vibrations, while damage in y-direction mainly influences the lateral vibrations. Among all the damaged bearings in this work, the influence of damage in x-direction has the least influence on the system. The damage in the fixed bearing is larger than that in other bearings, indicating that more attentions should be paid to the health monitoring of fixed bearings in railway engineering.","PeriodicalId":54741,"journal":{"name":"Mechanika","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44644064","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

Experimental Investigation of Thermal and Humidity Dynamics in the Enclosures Made of Non-Permeable Walls 非渗透墙围护结构的湿热动力学实验研究

IF 0.7 4区工程技术

Mechanika Pub Date : 2022-12-05 DOI: 10.5755/j02.mech.32240

Z. Staliulionis, G. Miliauskas, L. Paukštaitis, A. Balčius

{"title":"Experimental Investigation of Thermal and Humidity Dynamics in the Enclosures Made of Non-Permeable Walls","authors":"Z. Staliulionis, G. Miliauskas, L. Paukštaitis, A. Balčius","doi":"10.5755/j02.mech.32240","DOIUrl":"https://doi.org/10.5755/j02.mech.32240","url":null,"abstract":"The usage of electronics in outdoor environment is growing therefore the control of moisture related failures in electronics are becoming more important. The main cause of these failures is the humidity inside electronics which may condense on the surfaces or components. To protect electronics from harsh environment, the components and electronics are encapsulated by using electronics enclosures, however it does not prevent from moisture ingress through plastic walls, gaskets, cable feedthroughs and etc. Thus, to control the humidity, it is very important to understand the humidity ingress and behaviour in the electronics enclosures. Hence, the paper concerns the study of temperature and moisture dynamics when electronics enclosure is exposed to a cyclic temperature condition according to MIL-STD-810F. Two different enclosures were selected for the experiment, namely, aluminum enclosure and glass jar. The study was carried out in a climatic chamber and the measurements of temperature and relative humidity were performed using sensors. Different effect of enclosure material was considered for humidity ingress. In aluminum enclosure, results showed that the temperature difference between different points are smaller than in case of glass jar. Different temperatures in enclosures are determined by different boundary conditions outside the enclosure caused by the climatic chamber.","PeriodicalId":54741,"journal":{"name":"Mechanika","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44189919","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

Effects of Machining Parameters on Electrochemical Multi-Field Coupling 加工参数对电化学多场耦合的影响

IF 0.7 4区工程技术

Mechanika Pub Date : 2022-12-05 DOI: 10.5755/j02.mech.31499

Y. Chen, Xiang Li, Yichi Zhang, Jinyang Liu

{"title":"Effects of Machining Parameters on Electrochemical Multi-Field Coupling","authors":"Y. Chen, Xiang Li, Yichi Zhang, Jinyang Liu","doi":"10.5755/j02.mech.31499","DOIUrl":"https://doi.org/10.5755/j02.mech.31499","url":null,"abstract":"Electrochemical machining involves three couplings between electric field, flow field and thermal field. The precipitation of hydrogen on the surface of the cathode will affect the entire electrochemical machining process and the final machining quality of the workpiece. Finite element software is used to analyze the effects of different voltages, electrolyte inlet pressure and interelectrode gap on current density, hydrogen volume fraction, conductivity and temperature distribution in this article. The research results show that the increase of processing voltage will increase the current density, hydrogen volume fraction and temperature, and decrease the conductivity of the solution. As the pressure of the electrolyte increases, the current density and conductivity increase, but the hydrogen volume fraction and temperature decrease. The current density, hydrogen volume fraction and temperature decrease, and the conductivity increases when the gap between electrodes increases. At the inlet, the current density and conductivity are relatively large, and gradually decrease along the electrolyte flow direction, while the hydrogen volume fraction and temperature are the smallest at the inlet, and gradually accumulate along the electrolyte flow direction, and reach the maximum at the outlet. Through multi-physics coupling simulation, the current density, temperature, conductivity and bubble distribution in electrochemical machining can be predicted, which can provide a theoretical basis for actual electrochemical machining process parameter selection.","PeriodicalId":54741,"journal":{"name":"Mechanika","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46841052","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

The Effect of Mixing Recirculated Flue Gas with Primary or Secondary Air during Biomass Combustion in Grate-Firing Boiler as the Primary Measure for NOx Reduction 炉排锅炉生物质燃烧过程中再循环烟气与一次或二次风混合作为NOx减排主要措施的效果

IF 0.7 4区工程技术

Mechanika Pub Date : 2022-12-05 DOI: 10.5755/j02.mech.31475

Giedrius Jomantas, K. Buinevičius

{"title":"The Effect of Mixing Recirculated Flue Gas with Primary or Secondary Air during Biomass Combustion in Grate-Firing Boiler as the Primary Measure for NOx Reduction","authors":"Giedrius Jomantas, K. Buinevičius","doi":"10.5755/j02.mech.31475","DOIUrl":"https://doi.org/10.5755/j02.mech.31475","url":null,"abstract":"Due to the pollutant regulations of the Directive (EU) 2015/2193, the need to reduce the emissions of pollutant compounds such as NOx is of a great importance for industrial boilers. This study was performed to determine the effect of primary measures in reducing said pollutants by mixing primary or secondary air with FGR and supplying the mixture for combustion. The studies were conducted on low-scale industrial biomass grate-firing furnace and boiler stand of 25 kW. Sunflower husk pellets, shredded pine bark and wood pellets were combusted during these experiments and emissions of NOx in their combustion products were analyzed. The most significant reduction of emissions was achieved by mixing primary air and FGR and supplying it to the primary combustion zone – under the grate. The emissions of NOx were reduced by 29% and 15% for shredded pine bark and sunflower husk pellets respectively. The emissions of shredded pine bark were reduced enough to meet the standards of the EU Directive, unlike those of sunflower husk pellets. The possible ways to reach greater reduction of NOx by using primary measures are implementing staged combustion, supplying pure FGR and/or mixing agriculture waste with fuels containing less N in its composition.","PeriodicalId":54741,"journal":{"name":"Mechanika","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45503810","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

Helical Baffle Thermohydraulic Performance Versus Segmental Baffle One 螺旋折流板与节段折流板的热水力性能比较

IF 0.7 4区工程技术

Mechanika Pub Date : 2022-12-05 DOI: 10.5755/j02.mech.31096

M. Yousfi

引用次数: 0