Pub Date : 2022-12-20DOI: 10.54684/ijmmt.2022.14.2.286
M. Vasić
This paper goal was to increase the quality of the drying ware and to lower the drying scarp rate in one local brick factory. The registration of drying air parameters (temperature, humidity and velocity) along the dryer channels as well as the drying ware linear shrinkage and mass change were monitored for a month. Material and Energy balances were also recorded. Results have revealed that the drying air humidity and temperature profiles were not evenly distributed along the height of the drying tunnels. The ambient air breakthrough into the dryer was experimentally identified and quantified. It was the cause of the product quality deterioration and the reason why the critical and residual moisture in some of the products was larger than the desired one. Based on monitored data and mass and energy balances a solution was proposed for preventing the “false” air breakthrough, upgrade of the existing dryer fans and installation of the novel, measuring equipment. A hypothetical solution for increasing the capacity of the dryer, which uses the registered material and energy balances as well as factory management expectation, that the production of 50.000 masonry units per day will be achieved soon, was given also.
{"title":"MONITORING AND ANALYZING THE CLASSICAL COUNTER CURRENT INDUSTRIAL TUNNEL DRYER FOR MASONRY CLAY UNITS","authors":"M. Vasić","doi":"10.54684/ijmmt.2022.14.2.286","DOIUrl":"https://doi.org/10.54684/ijmmt.2022.14.2.286","url":null,"abstract":"This paper goal was to increase the quality of the drying ware and to lower the drying scarp rate in one local brick factory. The registration of drying air parameters (temperature, humidity and velocity) along the dryer channels as well as the drying ware linear shrinkage and mass change were monitored for a month. Material and Energy balances were also recorded. Results have revealed that the drying air humidity and temperature profiles were not evenly distributed along the height of the drying tunnels. The ambient air breakthrough into the dryer was experimentally identified and quantified. It was the cause of the product quality deterioration and the reason why the critical and residual moisture in some of the products was larger than the desired one. Based on monitored data and mass and energy balances a solution was proposed for preventing the “false” air breakthrough, upgrade of the existing dryer fans and installation of the novel, measuring equipment. A hypothetical solution for increasing the capacity of the dryer, which uses the registered material and energy balances as well as factory management expectation, that the production of 50.000 masonry units per day will be achieved soon, was given also.","PeriodicalId":38009,"journal":{"name":"International Journal of Modern Manufacturing Technologies","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45266700","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}
Pub Date : 2022-12-20DOI: 10.54684/ijmmt.2022.14.2.220
H. Ramezanalizadeh
Aluminum matrix cast composites (AMCCs) are engaged materials for the fabrication of accountable and especially acute pieces utilized in the high-tech scope of industry such as automotive, aerospace, electronics, etc. In the present study, hybrid aluminum base composite reinforced with in-situ produced Mg2Si and Al3Ni particles were fabricated successfully in casting moods, and the structural features of inborn reinforcing compounds was evaluated in different thermal situations of solidification. For this issue, the composite microstructure was characterized by X-ray diffraction (XRD) and optical microscope (OM). In addition, the mechanical properties were evaluated by hardness test. According to the results, increasing in the cooling rate during solidification leads to the reduction of mediate size of the Mg2Si initially crystals, enhancement of their dispensation uniformity and clear increasing of their final amount; meanwhile, the average size of Al3Ni particles decreases significantly but their content is almost the same for different conditions.
{"title":"HYBRID ALUMINUM MATRIX COMPOSITES REINFORCED WITH IN SITU MG2SI AND AL3NI PHASES","authors":"H. Ramezanalizadeh","doi":"10.54684/ijmmt.2022.14.2.220","DOIUrl":"https://doi.org/10.54684/ijmmt.2022.14.2.220","url":null,"abstract":"Aluminum matrix cast composites (AMCCs) are engaged materials for the fabrication of accountable and especially acute pieces utilized in the high-tech scope of industry such as automotive, aerospace, electronics, etc. In the present study, hybrid aluminum base composite reinforced with in-situ produced Mg2Si and Al3Ni particles were fabricated successfully in casting moods, and the structural features of inborn reinforcing compounds was evaluated in different thermal situations of solidification. For this issue, the composite microstructure was characterized by X-ray diffraction (XRD) and optical microscope (OM). In addition, the mechanical properties were evaluated by hardness test. According to the results, increasing in the cooling rate during solidification leads to the reduction of mediate size of the Mg2Si initially crystals, enhancement of their dispensation uniformity and clear increasing of their final amount; meanwhile, the average size of Al3Ni particles decreases significantly but their content is almost the same for different conditions.","PeriodicalId":38009,"journal":{"name":"International Journal of Modern Manufacturing Technologies","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47123474","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}
Pub Date : 2022-12-20DOI: 10.54684/ijmmt.2022.14.3.92
Cristina Georgiana Lateş, Cristina Mihaela Dragan, C. Dumitraș
The current paper aims to present a thermal dissipation optimization for an Electronic Control Unit (ECU) cooled with thermal paste. The improvement consists of replacing the inside air of the module with four single-phase dielectric coolants in natural convection and one silicone elastomer compound, each of which has a higher thermal conductivity than air. Two distinct experiments were performed: electronics immersed in coolant with and without thermal paste, exposed to an ambient temperature of between -40°C and 105°C. Temperature measurements on the hot spots of these solutions were compared to electronic modules that are cooled only with thermal paste.
{"title":"HEAT TRANSFER OPTIMIZATION OF AN ELECTRONIC CONTROL UNIT IMMERSED IN NATURAL CONVECTION COOLANT","authors":"Cristina Georgiana Lateş, Cristina Mihaela Dragan, C. Dumitraș","doi":"10.54684/ijmmt.2022.14.3.92","DOIUrl":"https://doi.org/10.54684/ijmmt.2022.14.3.92","url":null,"abstract":"The current paper aims to present a thermal dissipation optimization for an Electronic Control Unit (ECU) cooled with thermal paste. The improvement consists of replacing the inside air of the module with four single-phase dielectric coolants in natural convection and one silicone elastomer compound, each of which has a higher thermal conductivity than air. Two distinct experiments were performed: electronics immersed in coolant with and without thermal paste, exposed to an ambient temperature of between -40°C and 105°C. Temperature measurements on the hot spots of these solutions were compared to electronic modules that are cooled only with thermal paste.","PeriodicalId":38009,"journal":{"name":"International Journal of Modern Manufacturing Technologies","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41751894","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}
Pub Date : 2022-12-20DOI: 10.54684/ijmmt.2022.14.3.38
E. Chiba, M. Abdelkrim, A. Belloufi, I. Rezgui
The wheels and rails of the train, tram etc. are often verified from their microstructure and plastic deformation, which usually appear in the outer layer of a wheel and rail, to analyse the causes of geometrical defects by monitoring the applied loads and variation of the temperature as suggested in the literature. This paper studies the effect of thermal stress applied with variations of the loads in contact on wheel/rail for the tramway, tracking through the state of the rail to discover the causes of geometric defects started by temperature variations and loads, and applying these variations of temperature and loads to know its resistance to these climatic conditions. 3D model of temperature distrubtion and heat flow in the wheel and the rail ER6 and ER7 has been developped using the finite element method based on the COMSOL Multiphisics.
{"title":"\"THREE-DIMENSIONAL MODELLING OF RAILS / WHEELS MANUFACTURED BY ER6 AND ER7 IN TRAMWAY APPLICATIONS \"","authors":"E. Chiba, M. Abdelkrim, A. Belloufi, I. Rezgui","doi":"10.54684/ijmmt.2022.14.3.38","DOIUrl":"https://doi.org/10.54684/ijmmt.2022.14.3.38","url":null,"abstract":"The wheels and rails of the train, tram etc. are often verified from their microstructure and plastic deformation, which usually appear in the outer layer of a wheel and rail, to analyse the causes of geometrical defects by monitoring the applied loads and variation of the temperature as suggested in the literature. This paper studies the effect of thermal stress applied with variations of the loads in contact on wheel/rail for the tramway, tracking through the state of the rail to discover the causes of geometric defects started by temperature variations and loads, and applying these variations of temperature and loads to know its resistance to these climatic conditions. 3D model of temperature distrubtion and heat flow in the wheel and the rail ER6 and ER7 has been developped using the finite element method based on the COMSOL Multiphisics.","PeriodicalId":38009,"journal":{"name":"International Journal of Modern Manufacturing Technologies","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47901526","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}
Pub Date : 2022-12-20DOI: 10.54684/ijmmt.2022.14.3.27
G. Căpățână, M. A. Potîrniche, D. G. Muscă (Anghelache)
Although it has been neglected in recent years, cultivation is once again finding its place in the field of agricultural crop management. The basic activities carried out by farmers in modern agriculture include plowing, opening the top layer of the soil and mechanical removal of weeds. Tools such as harrows or cultivators are used for these activities. This work presents in the first phase the modeling of a cultivator that can be mounted on an agricultural tractor with a power of up to 20 kW. The 3D model of the cultivator was analyzed in a second phase using a specialized software, Autodesk Inventor Professional 2020. The finite element analysis aimed at highlighting the behavior of the cultivator type equipment during the work process, a very important aspect for the specialists in domain who must permanently ensure that the operation of these machines is carried out at optimal parameters. Following the analysis, the results chosen for visualization were the stresses and deformations of the cultivator's work equipment, as well as the displacements of the structure nodes.
尽管近年来耕作一直被忽视，但它再次在农业作物管理领域找到了自己的位置。在现代农业中，农民的基本活动包括翻耕、开土层和机械除草。锄头或耕犁等工具用于这些活动。这项工作在第一阶段提出了可安装在功率高达20千瓦的农业拖拉机上的耕耘机的建模。在第二阶段，使用专用软件Autodesk Inventor Professional 2020分析耕耘机的3D模型。有限元分析旨在突出耕作型设备在工作过程中的行为，这对该领域的专家来说是一个非常重要的方面，他们必须始终确保这些机器在最佳参数下运行。在分析之后，选择用于可视化的结果是耕耘机工作设备的应力和变形，以及结构节点的位移。
{"title":"CONSIDERATIONS REGARDING 3D MODELLING AND FINITE ELEMENT ANALYSIS OF A CULTIVATOR TYPE EQUIPMENT","authors":"G. Căpățână, M. A. Potîrniche, D. G. Muscă (Anghelache)","doi":"10.54684/ijmmt.2022.14.3.27","DOIUrl":"https://doi.org/10.54684/ijmmt.2022.14.3.27","url":null,"abstract":"Although it has been neglected in recent years, cultivation is once again finding its place in the field of agricultural crop management. The basic activities carried out by farmers in modern agriculture include plowing, opening the top layer of the soil and mechanical removal of weeds. Tools such as harrows or cultivators are used for these activities. This work presents in the first phase the modeling of a cultivator that can be mounted on an agricultural tractor with a power of up to 20 kW. The 3D model of the cultivator was analyzed in a second phase using a specialized software, Autodesk Inventor Professional 2020. The finite element analysis aimed at highlighting the behavior of the cultivator type equipment during the work process, a very important aspect for the specialists in domain who must permanently ensure that the operation of these machines is carried out at optimal parameters. Following the analysis, the results chosen for visualization were the stresses and deformations of the cultivator's work equipment, as well as the displacements of the structure nodes.","PeriodicalId":38009,"journal":{"name":"International Journal of Modern Manufacturing Technologies","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48614118","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}
Pub Date : 2022-12-20DOI: 10.54684/ijmmt.2022.14.3.76
S. Hudișteanu, Cristian Chereches, F. Țurcanu, N. Taranu, M. Verdeș, Ana-Diana Ancaş, I. Hudișteanu, D. Ungureanu, RA Polcovnicu
The paper presents the design and execution of a solar radiation simulation device, which ensures the adequate operation of thermal and photovoltaic panels by using light sources which have a spectrum close to the one produced by sun at minimum investment costs. The equipment is used for the experimental tracking of the behaviour of photovoltaic panels and solar thermal panels for both short and longer time intervals. The solar radiation simulation device has been developed to provide the radiation necessary for the evaluation of the efficiency and the heating of the solar panels exposed to sun. A system consisting of six OSRAM Ultravitalux 300W high-pressure lamps has been adopted, offering an optimized solution, both qualitatively and economically. The main steps achieved during its execution were: design, pre-dimensioning, verification, final dimensioning, execution and testing. According to the final tests, it was concluded that the proposed device can provide the quantitative and qualitative parameters required for solar radiation simulation in case of laboratory tests.
{"title":"SOLAR RADIATION SIMULATION DEVICE FOR INVESTIGATION OF THERMAL AND PHOTOVOLTAIC PANELS","authors":"S. Hudișteanu, Cristian Chereches, F. Țurcanu, N. Taranu, M. Verdeș, Ana-Diana Ancaş, I. Hudișteanu, D. Ungureanu, RA Polcovnicu","doi":"10.54684/ijmmt.2022.14.3.76","DOIUrl":"https://doi.org/10.54684/ijmmt.2022.14.3.76","url":null,"abstract":"The paper presents the design and execution of a solar radiation simulation device, which ensures the adequate operation of thermal and photovoltaic panels by using light sources which have a spectrum close to the one produced by sun at minimum investment costs. The equipment is used for the experimental tracking of the behaviour of photovoltaic panels and solar thermal panels for both short and longer time intervals. The solar radiation simulation device has been developed to provide the radiation necessary for the evaluation of the efficiency and the heating of the solar panels exposed to sun. A system consisting of six OSRAM Ultravitalux 300W high-pressure lamps has been adopted, offering an optimized solution, both qualitatively and economically. The main steps achieved during its execution were: design, pre-dimensioning, verification, final dimensioning, execution and testing. According to the final tests, it was concluded that the proposed device can provide the quantitative and qualitative parameters required for solar radiation simulation in case of laboratory tests.","PeriodicalId":38009,"journal":{"name":"International Journal of Modern Manufacturing Technologies","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48621447","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}
Pub Date : 2022-12-20DOI: 10.54684/ijmmt.2022.14.3.33
E. Cherecheş, M. Cherecheș, Liviu Zupcu, A. Minea
In the last years, a lot of research is dedicated to development of new heat transfer fluids. Phase change materials (PCM) are considered a new generation of heat transfer fluids. A convenient tool to verify the efficiency of a fluid PCM for different practical applications is the simulation approach. In order for such an analysis to be possible, it is necessary to correctly and completely describe the fluids, which supposes the knowledge of the laws of variation of the thermophysical properties with temperature. In many industrial applications, heat transfer is one of the most significant process, but the development of efficient equipment is limited by the low thermal conductivity of conventional heat transfer fluids. Complex CFD (computational fluid dynamics) programs, such as ANSYS Fluent, are capable of replacing experimental results. Therefore, based on previous experimental data, a numerical study on heat transfer will be performed, involving laminar flow conditions. In this numerical study, a number of nanofluids based on PEG 400 (polyethylene glycol PEG 400) and two type of nanoparticles (Al2O3 and ZnO), have been implemented in a commercial code to analyze their behavior at heating. Their heating behavior must be understood under different conditions or factors, such as concentration, temperature, pressure, flow conditions, heating systems and flow geometry. In conclusion, PEG 400 based nanofluids is considered to have a high potential for a number of practical applications (for example for their possible use in thermal energy storage), but further studies are needed, as well as the intensification of numerical and experimental research because no applied studies have been identified in the literature.
{"title":"CFD ANALYSIS OF PEG 400 BASED NANOFLUIDS","authors":"E. Cherecheş, M. Cherecheș, Liviu Zupcu, A. Minea","doi":"10.54684/ijmmt.2022.14.3.33","DOIUrl":"https://doi.org/10.54684/ijmmt.2022.14.3.33","url":null,"abstract":"In the last years, a lot of research is dedicated to development of new heat transfer fluids. Phase change materials (PCM) are considered a new generation of heat transfer fluids. A convenient tool to verify the efficiency of a fluid PCM for different practical applications is the simulation approach. In order for such an analysis to be possible, it is necessary to correctly and completely describe the fluids, which supposes the knowledge of the laws of variation of the thermophysical properties with temperature. In many industrial applications, heat transfer is one of the most significant process, but the development of efficient equipment is limited by the low thermal conductivity of conventional heat transfer fluids. Complex CFD (computational fluid dynamics) programs, such as ANSYS Fluent, are capable of replacing experimental results. Therefore, based on previous experimental data, a numerical study on heat transfer will be performed, involving laminar flow conditions. In this numerical study, a number of nanofluids based on PEG 400 (polyethylene glycol PEG 400) and two type of nanoparticles (Al2O3 and ZnO), have been implemented in a commercial code to analyze their behavior at heating. Their heating behavior must be understood under different conditions or factors, such as concentration, temperature, pressure, flow conditions, heating systems and flow geometry. In conclusion, PEG 400 based nanofluids is considered to have a high potential for a number of practical applications (for example for their possible use in thermal energy storage), but further studies are needed, as well as the intensification of numerical and experimental research because no applied studies have been identified in the literature.","PeriodicalId":38009,"journal":{"name":"International Journal of Modern Manufacturing Technologies","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43711738","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}
Pub Date : 2022-12-20DOI: 10.54684/ijmmt.2022.14.2.145
M. Mihălcică, M. Stanciu, H. Teodorescu, N. Iftimie
The paper presents the experimental investigations regarding the viscoelastic behaviour of maple wood used in the construction of stringed musical instruments. The studied samples were classified according to the anatomical structure of the wood in the four classes of anatomical quality used by the manufacturers of musical instruments. Based on the mechanical analysis in dynamic regime, the viscoelastic parameters were determined - the preservation module E', the loss modulus E' and the damping tan δ, in conditions of constant temperature, respectively variable temperature. It was found that the determined rheological quantities depend on the anatomical structure of the wood, the frequency of the excitation and the temperature.
{"title":"EVALUATION OF VISCOUS-ELASTIC PROPERTIES OF RESONANCE MAPLE WOOD","authors":"M. Mihălcică, M. Stanciu, H. Teodorescu, N. Iftimie","doi":"10.54684/ijmmt.2022.14.2.145","DOIUrl":"https://doi.org/10.54684/ijmmt.2022.14.2.145","url":null,"abstract":"The paper presents the experimental investigations regarding the viscoelastic behaviour of maple wood used in the construction of stringed musical instruments. The studied samples were classified according to the anatomical structure of the wood in the four classes of anatomical quality used by the manufacturers of musical instruments. Based on the mechanical analysis in dynamic regime, the viscoelastic parameters were determined - the preservation module E', the loss modulus E' and the damping tan δ, in conditions of constant temperature, respectively variable temperature. It was found that the determined rheological quantities depend on the anatomical structure of the wood, the frequency of the excitation and the temperature.","PeriodicalId":38009,"journal":{"name":"International Journal of Modern Manufacturing Technologies","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46329728","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}
Pub Date : 2022-12-20DOI: 10.54684/ijmmt.2022.14.2.294
D. Cerlinca, S. Spinu
The contacts of mechanical components transmit loads that lead to subsurface stresses developing in the contacting bodies. In an efficient tribological design, these stresses are expected to remain under the yield strength of the softer contacting material. When this condition is not met, plastic flow occurs in the softer body. Under the assumption of isotropic hardening, the yield strength increases with the development of additional plastic strains. As plastic flow processes are dissipative and therefore path dependent, the elastic-plastic problem is unsolvable through analytical endeavours, but can be approached with a numerical algorithm capable of simulating the loading history. The Betti’s reciprocal theorem provides the theoretical framework for the application of superposition principle to elastic-plastic stresses and displacement. An algorithm consisting in three nested loops is assembled from the solutions of simpler problems: (1) the purely elastic rough contact problem, (2) the inclusion problem and (3) the problem of the plastic strain increment. The numerical simulations suggest that the residual stresses decrease the intensity of the total stresses, thus delaying additional plastic flow. With increasing load, the heart-shaped plastic strain volume advances toward the surface, enveloping a plastic core near the initial point of contact. Compared to the purely elastic case, the elastic-plastic pressure shows a flatter distribution, while the contact radius is increased.
{"title":"\"NUMERICAL SIMULATION OF ELASTIC-PLASTIC CONTACT WITH ISOTROPIC HARDENING \"","authors":"D. Cerlinca, S. Spinu","doi":"10.54684/ijmmt.2022.14.2.294","DOIUrl":"https://doi.org/10.54684/ijmmt.2022.14.2.294","url":null,"abstract":"The contacts of mechanical components transmit loads that lead to subsurface stresses developing in the contacting bodies. In an efficient tribological design, these stresses are expected to remain under the yield strength of the softer contacting material. When this condition is not met, plastic flow occurs in the softer body. Under the assumption of isotropic hardening, the yield strength increases with the development of additional plastic strains. As plastic flow processes are dissipative and therefore path dependent, the elastic-plastic problem is unsolvable through analytical endeavours, but can be approached with a numerical algorithm capable of simulating the loading history. The Betti’s reciprocal theorem provides the theoretical framework for the application of superposition principle to elastic-plastic stresses and displacement. An algorithm consisting in three nested loops is assembled from the solutions of simpler problems: (1) the purely elastic rough contact problem, (2) the inclusion problem and (3) the problem of the plastic strain increment. The numerical simulations suggest that the residual stresses decrease the intensity of the total stresses, thus delaying additional plastic flow. With increasing load, the heart-shaped plastic strain volume advances toward the surface, enveloping a plastic core near the initial point of contact. Compared to the purely elastic case, the elastic-plastic pressure shows a flatter distribution, while the contact radius is increased.","PeriodicalId":38009,"journal":{"name":"International Journal of Modern Manufacturing Technologies","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46585615","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}
Pub Date : 2022-12-20DOI: 10.54684/ijmmt.2022.14.2.258
M. Szabo, M. Dochia, Valentin Muller, L. Jitaru
The aim’s paper was to study some physico-mechanical properties for fashion tights and medicinal tights with compression degree 1 (ie 10-15 mm Hg), class 1, for the prevention of venous diseases of the legs. Tights made of PA (polyamide) and two-component yarns, polyamide, and elastane, with a fineness of 70 Den, were chosen for the study. For fashion tights, the yarn composition was 88% polyamide and 12% elastane, and for medicinal tights 85% polyamide and 15% elastane. The tights were made on circular knitting machines with small diameter, Merz, model CC4 II with a diameter of 4 ¾ inches, pitch 24 E, number of needles 360, for the average size, M (II) of the tights. Both types of women's tights were made in a jersey structure with weft yarns. The background yarns were 100% polyamide, and the weft yarns were elastomer yarns coated in two polyamide yarns to obtain a balanced yarn. Fashion tights are the common ones, and compressive tights are used to prevent incipient venous disorders of the legs, calming the sensation of pain or heavy legs. The experimental program included the study of hygroscopicity, the tensile strength in the direction of the wales, and the degree of compression at the ankle. The obtained data were analysed and presented comparatively.
{"title":"THE STUDY OF THE PHYSICO-MECHANICAL PROPERTIES OF FASHION TIGHTS COMPARED TO MEDICINAL TIGHTS","authors":"M. Szabo, M. Dochia, Valentin Muller, L. Jitaru","doi":"10.54684/ijmmt.2022.14.2.258","DOIUrl":"https://doi.org/10.54684/ijmmt.2022.14.2.258","url":null,"abstract":"The aim’s paper was to study some physico-mechanical properties for fashion tights and medicinal tights with compression degree 1 (ie 10-15 mm Hg), class 1, for the prevention of venous diseases of the legs. Tights made of PA (polyamide) and two-component yarns, polyamide, and elastane, with a fineness of 70 Den, were chosen for the study. For fashion tights, the yarn composition was 88% polyamide and 12% elastane, and for medicinal tights 85% polyamide and 15% elastane. The tights were made on circular knitting machines with small diameter, Merz, model CC4 II with a diameter of 4 ¾ inches, pitch 24 E, number of needles 360, for the average size, M (II) of the tights. Both types of women's tights were made in a jersey structure with weft yarns. The background yarns were 100% polyamide, and the weft yarns were elastomer yarns coated in two polyamide yarns to obtain a balanced yarn. Fashion tights are the common ones, and compressive tights are used to prevent incipient venous disorders of the legs, calming the sensation of pain or heavy legs. The experimental program included the study of hygroscopicity, the tensile strength in the direction of the wales, and the degree of compression at the ankle. The obtained data were analysed and presented comparatively.","PeriodicalId":38009,"journal":{"name":"International Journal of Modern Manufacturing Technologies","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47035924","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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