: Knowledge of soil hydraulic properties is essential for modelling hydrodynamic phenomenons in soils under variably saturated conditions. This contribution focuses specifically on the properties of the top layer of soil which fundamentally influences the rainfall-runoff process, but the laboratory experimental proce-dures for the top-soil are very limited due to e.g. vegetation disturbing the experimental samples. The Richards equation describing the soil water flow process is here parameterised by the Mualem-van Genuchten model. The identification of the soil hydraulic parameters of this model is based on an in situ measurement of the single ring infiltration experiment. The experimental data and a priori information about parameters’ values are combined according to Bayes’ rule in order to obtain an updated probabilistic description of unknown parameters. The Bayesian inference is realized by the Markov chain Carlo method based on a less time-consuming polynomial approximation of the Mualem-van Genuchten model.
{"title":"PROBABILISTIC IDENTIFICATION OF UNSATURATED SOIL HYDRAULIC PROPERTIES FROM SINGLE RING INFILTRATION EXPERIMENT","authors":"E. Janouchova, A. Kucerová, M. Kuráz","doi":"10.21495/71-0-165","DOIUrl":"https://doi.org/10.21495/71-0-165","url":null,"abstract":": Knowledge of soil hydraulic properties is essential for modelling hydrodynamic phenomenons in soils under variably saturated conditions. This contribution focuses specifically on the properties of the top layer of soil which fundamentally influences the rainfall-runoff process, but the laboratory experimental proce-dures for the top-soil are very limited due to e.g. vegetation disturbing the experimental samples. The Richards equation describing the soil water flow process is here parameterised by the Mualem-van Genuchten model. The identification of the soil hydraulic parameters of this model is based on an in situ measurement of the single ring infiltration experiment. The experimental data and a priori information about parameters’ values are combined according to Bayes’ rule in order to obtain an updated probabilistic description of unknown parameters. The Bayesian inference is realized by the Markov chain Carlo method based on a less time-consuming polynomial approximation of the Mualem-van Genuchten model.","PeriodicalId":197313,"journal":{"name":"Engineering Mechanics 2019","volume":"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":"129285812","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}
Presented paper is focused on the design of timber joints with inserted steel sheet. Topicality of the problematic is presented together with a description of joints with the inner steel plate design and failure modes. The design resistance calculation is described in detail. The numerical model created in finite element software Abaqus is described. The analytical model was considered according to code EN 1995-1-1 (2006). The aim of this research is to show and compare numerical results of the timber joint with the current codified procedure provided by EN 1995-1-1 (2006), the general method and some proposals developed by other researchers recently. Furthermore, research results provide backgroung for the numerical software creation dealing with steel-timber joints. The numerical model validation made based on the analytical model is presented. Experimental programme is presented and its data serve for numerical model validation, as well.
{"title":"ADVANCED DESIGN OF JOINTS WITH STEEL ELEMENTS IN TIMBER STRUCTURES","authors":"K. Vopatová, B. Židlický, M. Kuříková, K. Cábová","doi":"10.21495/71-0-395","DOIUrl":"https://doi.org/10.21495/71-0-395","url":null,"abstract":"Presented paper is focused on the design of timber joints with inserted steel sheet. Topicality of the problematic is presented together with a description of joints with the inner steel plate design and failure modes. The design resistance calculation is described in detail. The numerical model created in finite element software Abaqus is described. The analytical model was considered according to code EN 1995-1-1 (2006). The aim of this research is to show and compare numerical results of the timber joint with the current codified procedure provided by EN 1995-1-1 (2006), the general method and some proposals developed by other researchers recently. Furthermore, research results provide backgroung for the numerical software creation dealing with steel-timber joints. The numerical model validation made based on the analytical model is presented. Experimental programme is presented and its data serve for numerical model validation, as well.","PeriodicalId":197313,"journal":{"name":"Engineering Mechanics 2019","volume":"212 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":"132336620","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}
A. Łukowska, P. Tomaszuk, K. Dzierżek, K. Kamienski, P. Rółkowski, M. Ostaszewski
: The inverted pendulum is a classic example commonly found in control theory. Double inverted pendulum which is a combination of inverted pendulum and double pendulum makes the control problem more challenging. The purpose of this work was to design an optimal mechanical construction of a linear double inverted pendulum on a cart. Pendulums usually have the form of a freely attached rod to the cart moving in one dimension. The presented system assumes the functionality which ensures better efficiency. The main determinant of optimal parameters is the stabilization of the pendulum in vertical position and control of the position of the cart on the guide rail. The general concept outlined at the beginning presents the key elements necessary for the proper operation of the system. In some systems available in the literature and Internet, the engine moves with the cart, increasing the inertia forces acting on it. In the designed system, it was decided to fix the motor to the base. The engine in such a system should have the precise control and a high starting torque that allows stabilization of the pendulum. The presented conception base on the most optimal selection of all components.
{"title":"OPTIMAL DESIGN OF THE DOUBLE INVERTED PENDULUM","authors":"A. Łukowska, P. Tomaszuk, K. Dzierżek, K. Kamienski, P. Rółkowski, M. Ostaszewski","doi":"10.21495/71-0-235","DOIUrl":"https://doi.org/10.21495/71-0-235","url":null,"abstract":": The inverted pendulum is a classic example commonly found in control theory. Double inverted pendulum which is a combination of inverted pendulum and double pendulum makes the control problem more challenging. The purpose of this work was to design an optimal mechanical construction of a linear double inverted pendulum on a cart. Pendulums usually have the form of a freely attached rod to the cart moving in one dimension. The presented system assumes the functionality which ensures better efficiency. The main determinant of optimal parameters is the stabilization of the pendulum in vertical position and control of the position of the cart on the guide rail. The general concept outlined at the beginning presents the key elements necessary for the proper operation of the system. In some systems available in the literature and Internet, the engine moves with the cart, increasing the inertia forces acting on it. In the designed system, it was decided to fix the motor to the base. The engine in such a system should have the precise control and a high starting torque that allows stabilization of the pendulum. The presented conception base on the most optimal selection of all components.","PeriodicalId":197313,"journal":{"name":"Engineering Mechanics 2019","volume":"9 17 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":"115795193","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}
the paper discusses the issue of testing the energy consumption of forklift trucks versus its movement parameters, such as radius of curve, distance, speed of movement on curve due to cargo safety, braking delay due to cargo slipping off the forks or tipping over. A comparative analysis of forklift truck operation characteristics in predefined work cycles: VDI cycle and "semi-trailer loading cycle" was presented; indicators characterizing the energy consumption of the truck were developed, the analysis of results was presented and final conclusions were elaborated.
{"title":"TESTING OF FORKLIFT TRUCK OPERATION IN PREDEFINED WORK CYCLES","authors":"P. Zając","doi":"10.21495/71-0-411","DOIUrl":"https://doi.org/10.21495/71-0-411","url":null,"abstract":"the paper discusses the issue of testing the energy consumption of forklift trucks versus its movement parameters, such as radius of curve, distance, speed of movement on curve due to cargo safety, braking delay due to cargo slipping off the forks or tipping over. A comparative analysis of forklift truck operation characteristics in predefined work cycles: VDI cycle and \"semi-trailer loading cycle\" was presented; indicators characterizing the energy consumption of the truck were developed, the analysis of results was presented and final conclusions were elaborated.","PeriodicalId":197313,"journal":{"name":"Engineering Mechanics 2019","volume":"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":"132609729","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}
: The paper is focused on welded slender stainless steel beams subjected to major bending moment. Difference in behaviour of stainless steel and common carbon steel is generally known, but design of stainless steel members is established mainly for hollow sections (CHS, SHS/RHS) as these are typical stainless steel profiles. Currently, open sections are also being used in structures and the design rules for both local buckling of very slender section as well as lateral-torsional buckling curves are based on very limited experimental and numerical research especially cross section Class 4. For this reason, six beams made of two types of stainless steel with different slenderness for lateral-torsional buckling were tested. Additionally, numerical GMNIA models of these beams are successfully validated. A parametric study based on the validated models will be used for development of a new accurate and safe design procedure.
{"title":"LATERAL-TORSIONAL BUCKLING OF WELDED SLENDER STAINLESS STEEL I BEAMS","authors":"M. Šorf, M. Jandera","doi":"10.21495/71-0-363","DOIUrl":"https://doi.org/10.21495/71-0-363","url":null,"abstract":": The paper is focused on welded slender stainless steel beams subjected to major bending moment. Difference in behaviour of stainless steel and common carbon steel is generally known, but design of stainless steel members is established mainly for hollow sections (CHS, SHS/RHS) as these are typical stainless steel profiles. Currently, open sections are also being used in structures and the design rules for both local buckling of very slender section as well as lateral-torsional buckling curves are based on very limited experimental and numerical research especially cross section Class 4. For this reason, six beams made of two types of stainless steel with different slenderness for lateral-torsional buckling were tested. Additionally, numerical GMNIA models of these beams are successfully validated. A parametric study based on the validated models will be used for development of a new accurate and safe design procedure.","PeriodicalId":197313,"journal":{"name":"Engineering Mechanics 2019","volume":"126 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":"116090852","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}
: This paper focuses on the comparing of the results of the FEM simulations of fused silica nanoindentation tests. Fused silica is modelled like bilinear elasto-plastic material with the parameters estimated from the experiment. FEM simulations are made with the 2D axisymmetric conical indenter which is equivalent to the Berkovich indenter and the indentation curves are evaluated. The FEM simulations were made with the rigid and the non-rigid indenter and the difference between the indentation curves obtained with these models is assessed. The evaluated indentation curves are compared with the indentation curves obtained from the experiment.
{"title":"FEM SIMULATION OF THE NANOINDENTATION TEST WITH RIGID AND NON-RIGID INDENTER","authors":"J. Kovář, V. Fuis","doi":"10.21495/71-0-189","DOIUrl":"https://doi.org/10.21495/71-0-189","url":null,"abstract":": This paper focuses on the comparing of the results of the FEM simulations of fused silica nanoindentation tests. Fused silica is modelled like bilinear elasto-plastic material with the parameters estimated from the experiment. FEM simulations are made with the 2D axisymmetric conical indenter which is equivalent to the Berkovich indenter and the indentation curves are evaluated. The FEM simulations were made with the rigid and the non-rigid indenter and the difference between the indentation curves obtained with these models is assessed. The evaluated indentation curves are compared with the indentation curves obtained from the experiment.","PeriodicalId":197313,"journal":{"name":"Engineering Mechanics 2019","volume":"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":"128485628","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}
: A mechanical problem on tracing the stress-strain state evolution of a sufficiently high conical column bearing a variable central axial loading on its upper end and being simultaneously built up by means of additive layer-by-layer piecewise continuous augmenting with new viscoelastic ageing material over the side surface is investigated. The acting axial force magnitude, the radius of the increasing bearing end, and the slope angle of the side surface are arbitrarily changing during the considered augmenting process. The closed-form analytical solution of the corresponding non-classical boundary-value problem is obtained.
{"title":"BUILDING UP A BEARING COLUMN OF AGEING VISCOELASTIC MATERIAL UNDER SIMULTANEOUS ACTION OF LOADING","authors":"D. Parshin","doi":"10.21495/71-0-267","DOIUrl":"https://doi.org/10.21495/71-0-267","url":null,"abstract":": A mechanical problem on tracing the stress-strain state evolution of a sufficiently high conical column bearing a variable central axial loading on its upper end and being simultaneously built up by means of additive layer-by-layer piecewise continuous augmenting with new viscoelastic ageing material over the side surface is investigated. The acting axial force magnitude, the radius of the increasing bearing end, and the slope angle of the side surface are arbitrarily changing during the considered augmenting process. The closed-form analytical solution of the corresponding non-classical boundary-value problem is obtained.","PeriodicalId":197313,"journal":{"name":"Engineering Mechanics 2019","volume":"56 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":"122930602","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}
Mixed plain boundary value problem is considered for the elastic rectangular domain. The conditions of first main elasticity problem are given at the lateral sides; the conditions of smooth contact are given at the base. The rectangular domain is under impact of the exterior static load at its upper edge. With the integral transformation method the problem is reduced to a vector boundary problem, where the unknown vector consists of the displacement`s transforms. The solution of vector boundary problem is constructed with the help of matrix differential calculations and has the unknown function. To find this function the integral singular equation is derived and solved with the help of the orthogonal polynomial method. The stress state of the rectangular domain is investigated depending on its size and kinds of impact.
{"title":"MIXED PLAIN BOUNDARY VALUE PROBLEM OF ELASTICITY FOR A RECTANGULAR DOMAIN","authors":"D. Nerukh, O. Pozhylenkov, N. Vaysfeld","doi":"10.21495/71-0-255","DOIUrl":"https://doi.org/10.21495/71-0-255","url":null,"abstract":"Mixed plain boundary value problem is considered for the elastic rectangular domain. The conditions of first main elasticity problem are given at the lateral sides; the conditions of smooth contact are given at the base. The rectangular domain is under impact of the exterior static load at its upper edge. With the integral transformation method the problem is reduced to a vector boundary problem, where the unknown vector consists of the displacement`s transforms. The solution of vector boundary problem is constructed with the help of matrix differential calculations and has the unknown function. To find this function the integral singular equation is derived and solved with the help of the orthogonal polynomial method. The stress state of the rectangular domain is investigated depending on its size and kinds of impact.","PeriodicalId":197313,"journal":{"name":"Engineering Mechanics 2019","volume":"25 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":"122291245","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":"NUMERICAL SIMULATION OF THE GAS FLOW THROUGH THE FENCES AND POROUS MEDIA","authors":"M. Kyncl, J. Pelant","doi":"10.21495/71-0-231","DOIUrl":"https://doi.org/10.21495/71-0-231","url":null,"abstract":"","PeriodicalId":197313,"journal":{"name":"Engineering Mechanics 2019","volume":"2 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":"126507227","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}
Welded joint strength depends on the correlation factor βw, which should be taken 1.0 for all stainless-steel families (according to Eurocode 3 (EN 1993-1-4, 2006)). The aim of this study is to investigate the strength and failure mode of the welded stainless-steel joints to determine the value of the correlation factor βw for austenitic grade EN 1.4301 based on experiments. The experiments investigation consists of tensile tests of two plates (15 mm thick) connected by four longitudinal fillet welds. The load was applied parallel to the weld causing only shear stress in the fillet weld. Every specimen was tested to investigate the strength, strain and failure mode.
焊接接头强度取决于相关系数βw，所有不锈钢系列的相关系数应为1.0(根据欧洲规范3 (EN 1993-1- 4,2006))。本研究的目的是研究焊接不锈钢接头的强度和破坏模式，并在实验的基础上确定EN 1.4301奥氏体等级的相关因子βw的值。实验研究包括两个板(15mm厚)由四个纵向角焊缝连接的拉伸试验。载荷平行于焊缝施加，在角焊缝中只产生剪切应力。每个试件都进行了强度、应变和破坏模式的测试。
{"title":"DESIGN RESISTANCE OF STAINLESS-STEEL FILLET WELDS","authors":"N. Feber, M. Jandera, L. Forejtová","doi":"10.21495/71-0-101","DOIUrl":"https://doi.org/10.21495/71-0-101","url":null,"abstract":"Welded joint strength depends on the correlation factor βw, which should be taken 1.0 for all stainless-steel families (according to Eurocode 3 (EN 1993-1-4, 2006)). The aim of this study is to investigate the strength and failure mode of the welded stainless-steel joints to determine the value of the correlation factor βw for austenitic grade EN 1.4301 based on experiments. The experiments investigation consists of tensile tests of two plates (15 mm thick) connected by four longitudinal fillet welds. The load was applied parallel to the weld causing only shear stress in the fillet weld. Every specimen was tested to investigate the strength, strain and failure mode.","PeriodicalId":197313,"journal":{"name":"Engineering Mechanics 2019","volume":"316 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113998778","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}
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