Engineering Mechanics 2019最新文献

{"title":"DESIGN OF THE MANIPULATOR CONTROL UNIT FOR MODERNITY MARS ROVER","authors":"P. Ptak, K. Sokół, D. Cekus","doi":"10.21495/71-0-299","DOIUrl":"https://doi.org/10.21495/71-0-299","url":null,"abstract":": In this paper the design process of the manipulator control unit for Modernity II rover is presented. The rover was used in University Rover Challenge 2018 organized by Mars Society in Utah, USA and finished the challenge in the first place. The design of the present version of the manipulator (V5) required initial project, prototype design, experimental tests, mechanical and electronical improvements. The paper covers the requirements of the manipulator design and the procedures of selection of the elements for the control unit.","PeriodicalId":197313,"journal":{"name":"Engineering Mechanics 2019","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126344918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"EXPERIMENTAL VERIFICATION OF POLYMERIC DISTILLATION UNIT","authors":"T. Kroulíková, T. Brozova, E. Bartuli, M. Raudenský","doi":"10.21495/71-0-211","DOIUrl":"https://doi.org/10.21495/71-0-211","url":null,"abstract":": Desalination is common solution to a fresh water scarcity. The common desalination units are made of metal, which bring some disadvantage as corrosion or heavy weight. The presented paper discribe principle of polymeric distillation and present results of experimental verification of prototype of fully polymeric distillation. This prototype is based on air gap membrane distillation and combines two type of polymeric hollow fibers. Porous hollow fibers were used as membrane and the non-porous hollow fibers were used for the condenser. The prototype was operated in long-term continuous operation. Six experiments with different flow rate and temperature were done. During testing the temperature, humidity and amount of condensate was measured.","PeriodicalId":197313,"journal":{"name":"Engineering Mechanics 2019","volume":"92 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126029189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"FLOW BEHAVIOUR IN COMPRESSION TEST UNDER VARIOUS LUBRICATION CONDITIONS","authors":"F. Šebek, J. Zapletal, P. Kubík, J. Petruška","doi":"10.21495/71-0-351","DOIUrl":"https://doi.org/10.21495/71-0-351","url":null,"abstract":": The compression test provides a useful information about the material flow under large plastic deformations, when compared to the standard tensile test. On the other hand, it is heavily dependent on the lubrication conditions. The paper deals with two di ff erent specimen geometries resulting in two di ff erent friction conditions. The first geometry corresponds to the classical smooth cylinder. The second one was designed according to the idea of Rastegaev. It is a smooth cylinder with grooves on both faces (bases), which allow the lubricant to accumulate and prevent it from escaping the region, where the punches are in the contact with specimen. Then, both cases were computationally simulated and compared with experiments.","PeriodicalId":197313,"journal":{"name":"Engineering Mechanics 2019","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124056615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"EXPERIMENTAL AND NUMERICAL RESEARCH ON ARCH VORTEX","authors":"V. Barraclough, P. Safarik","doi":"10.21495/71-0-37","DOIUrl":"https://doi.org/10.21495/71-0-37","url":null,"abstract":"","PeriodicalId":197313,"journal":{"name":"Engineering Mechanics 2019","volume":"84 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128563353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"STEP PLANNING ALGORITHM FOR N-LEGGED WALKING ROBOT WITH SMOOTH DIRECTION CONTROL","authors":"J. Králik, V. Venglár","doi":"10.21495/71-0-199","DOIUrl":"https://doi.org/10.21495/71-0-199","url":null,"abstract":"Precise step-planning algorithm is important when we want to drive an n-legged walking robot. Probably the most widely used precise control system is based on neural networks, but those require a lot of computing power. The main goal of this paper is to propose a computationally efficient method for precise and smooth movement of a robot. An algorithm capable of computing end-step position based on movement around a circle was developed. It can be driven by control vector or (with minor modification) by a radius and a tangent. It is simple to implement, adjust and debug, and needs only a small amount of computational power. The proposed algorithm only generates the end points of each step. It can be used as a basis for more complex solution and can be also used in a system with a large number of legs. The movement of body, the kinematics of mechanical parts and the manipulation of center of mass must be solved by other algorithms.","PeriodicalId":197313,"journal":{"name":"Engineering Mechanics 2019","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127898233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ROTATIONAL SPEED LIMIT OF ACTIVELY CONTROLLED JOURNAL BEARINGS AT STABLE LUBRICATION","authors":"J. Tuma, A. Víteček","doi":"10.21495/71-0-375","DOIUrl":"https://doi.org/10.21495/71-0-375","url":null,"abstract":": The paper deals with the stability of the journal motion in hydrodynamic journal bearings while actively controlling their vibrations by the position of the bearing bushing. The bearing journal motion can only be stable when lubrication is stable. The first chapter of the paper contains a description of the conditions for forming a stable oil film. The paper deals with the mathematical model of the journal bearing with a fixed and movable bushing. The analysis uses verified mathematical models in the form of motion equations describing the motion of the journal axis in the plane which is perpendicular to the rotor axis in contrast to the magnetic bearing; the equations are coupled. The stability analysis aims to determine the critical rotational speed of the rotor at which vibrations of the whirl type are generated. The stability analysis tool is the Nyquist Criterion.","PeriodicalId":197313,"journal":{"name":"Engineering Mechanics 2019","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129777998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"FOUR-POINT BENDING TESTS OF DOUBLE LAMINATED GLASS PANELS WITH EVA INTERLAYER IN VARIOUS LOADING RATES","authors":"T. Hána, M. Eliášová, Z. Sokol, M. Vokáč","doi":"10.21495/71-0-145","DOIUrl":"https://doi.org/10.21495/71-0-145","url":null,"abstract":": Current architecture tends to use glass as a load-bearing material thus glass beams, panels, columns or even stairs may be found. These members are mostly made of laminated glass with polymeric interlayer. Laminated glass performs good response in accidental situation because glass fragments stay attached to the interlayer and do not cause harmful injuries. Polymeric interlayer is able to ensure the transfer of shear forces between the individual panes in a perpendicularly loaded panel. This transfer depends on the shear stiffness of the interlayer as a time and temperature-dependent parameter which is not usually available. Civil engineers thus neglect this stiffness to stay on a safe side. This paper shows the experimental data gained from four-point bending tests of double-laminated glass panels with EVA based interlayer (Evalam 80/120 ® ) loaded in three various loading rates and illustrates the influence of the loading rate on the stress-state and vertical deflections of a panel. The analogy with shear stiffness of another EVA based interlayer (Evasafe ® ) is further commented. All experiments were performed at CTU in Prague. time domain. To verify small-scale experiments, large-scale four-point bending tests of double-laminated glass panels are appropriate. This paper describes performed experiments at CTU in Prague and introduces the experimental data, particularly normal stresses and vertical deflections at the mid-span cross section obtained from four-point bending tests of double-laminated heat toughened glass panels laminated with EVA (Evalam 80/120 ® ) interlayer. Bending tests were executed at three various loading rates. The analogy of experimental results with published initial shear stiffness of another EVA based interlayer (Evasafe ® ) obtained from quasi-static tests is further commented. Experimentally verified shear stiffness of polymeric interlayers used in laminated glass enables to capture the shear coupling of glass panes more precisely and enables to design more economical and simultaneously safe glass structures in practice.","PeriodicalId":197313,"journal":{"name":"Engineering Mechanics 2019","volume":"136-137 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131750415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MAGNETORHEOLOGICAL FLUIDS: STRIBECK CURVES DESCRIBING THE BOUNDARY, MIXED AND EHD REGIME OF LUBRICATION","authors":"J. Roupec, Z. Strecker, M. Kubík, O. Macháček, J. Smilka, M. Smilková, I. Mazůrek","doi":"10.21495/71-0-323","DOIUrl":"https://doi.org/10.21495/71-0-323","url":null,"abstract":"","PeriodicalId":197313,"journal":{"name":"Engineering Mechanics 2019","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134252034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"REDUCING THE ADHESION FORCE OF THE WHEELS OF THE ROAD VEHICLES","authors":"P. Jílek, I. Sefcik, J. Verner","doi":"10.21495/71-0-173","DOIUrl":"https://doi.org/10.21495/71-0-173","url":null,"abstract":": The article deals with influence of the controlled adhesion force in the contact between a wheel of a road vehicle and a road. In the first section, a way to reach a decrease of adhesion force is presented. Then follows description of the experimental vehicle, which experimental measurements were realized on. The mutual assessment of the advantages and disadvantages of the both experimental test methods is presented next. The purpose of the article is to discover difference between vehicle’s behavior when the adhesion force is influenced by the change of the reaction force and by the change of the adhesion coefficient.","PeriodicalId":197313,"journal":{"name":"Engineering Mechanics 2019","volume":" 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120937400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DAMPING OF DISK BODIES VIBRATIONS","authors":"L. Pust, L. Pešek, P. Šnábl","doi":"10.21495/71-0-303","DOIUrl":"https://doi.org/10.21495/71-0-303","url":null,"abstract":"","PeriodicalId":197313,"journal":{"name":"Engineering Mechanics 2019","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124590961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}