Pub Date : 2021-01-01DOI: 10.5267/J.ESM.2021.1.002
R. Khorasani, S. A. H. Kordkheili, H. Parviz
This work aims to present an experimentally verified analytical solution to examine damping properties of systems including viscoelastic treatments. Although there are several methods for characterizing the behavior of three-layer damping systems, the RKU method is the most frequently used one. In this paper, this method is modified such a way that to be applied for a five-layer damping system. The achieved analytical relations are then employed to study the effects of a four-layer vibration-absorbing coating on the dynamic behavior of an aluminum sheet with free-free boundary conditions. Since the vibration-damping properties of the coating are unknowns, its loss factor and shear modulus are experimentally extracted based on the ASTM E756-05 standard method. The comparison between the analytical solution and performed modal tests expresses the efficiency of the presented method.
{"title":"An analytical and experimental study on dampening material effects on the dynamic behavior of free-free aluminum sheets","authors":"R. Khorasani, S. A. H. Kordkheili, H. Parviz","doi":"10.5267/J.ESM.2021.1.002","DOIUrl":"https://doi.org/10.5267/J.ESM.2021.1.002","url":null,"abstract":"This work aims to present an experimentally verified analytical solution to examine damping properties of systems including viscoelastic treatments. Although there are several methods for characterizing the behavior of three-layer damping systems, the RKU method is the most frequently used one. In this paper, this method is modified such a way that to be applied for a five-layer damping system. The achieved analytical relations are then employed to study the effects of a four-layer vibration-absorbing coating on the dynamic behavior of an aluminum sheet with free-free boundary conditions. Since the vibration-damping properties of the coating are unknowns, its loss factor and shear modulus are experimentally extracted based on the ASTM E756-05 standard method. The comparison between the analytical solution and performed modal tests expresses the efficiency of the presented method.","PeriodicalId":37952,"journal":{"name":"Engineering Solid Mechanics","volume":"1 1","pages":"111-122"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70759015","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 : 2021-01-01DOI: 10.5267/J.ESM.2021.1.005
S. Hakimi, A. Soualem
The forming steps by permanent deformation controlled by the tools generate a distribution of stresses inside the material which directly depends on the work hardening properties of the latter. The change in boundary conditions following the removal of the tools imposes the material to redistribute the stresses in the sections in a manner compatible with the new boundary conditions. This new distribution necessarily operates by local elastic deformations that result globally in a general change of shape called springback. This geometrical deviation can be minimized by the meticulous focus of the tools, but it cannot generally be completely annihilated due to the influence of several parameters. For this reason, the study of the influence of the different technological factors and physico-metallurgical parameters on the springback for the different metals is very important to design and properly realize forming tools. The main objective of this work is to find solutions to problems encountered in sheet metal forming such as the problem of springback. Our work has two essential purposes: the first is summarized in an experimental study based on theoretical analyses. To this end, much effort is made to add a new design of parts for a U-type stretch-bending device and adapt it to a tensile testing machine. This design has the advantage of modifying and assembling all parameters affecting springback at the same time and also of carrying out several forming processes on the same device. The second goal is the experimental and numerical prediction of springback, and the study of the effect of various stretch-bending process parameters such as punch velocity, the orientation of the sheet (anisotropy), hold time and punch-die clearance on springback behavior under heat treatment of aluminum alloy sheets with three different rolling directions (0°,45°,90°). A finite element (FE) model of stretch-bending has been established by utilizing ABAQUS/CAE software. From this analysis, it can be concluded that the springback is affected by the anisotropy of the sheet and the heat treatment in the stretch-bending process. The obtained experimental results were compared with the numerical simulations found in good agreement.
{"title":"Evaluation of the sensitivity of springback to various process parameters of aluminum alloy sheet with different heat treatment conditions","authors":"S. Hakimi, A. Soualem","doi":"10.5267/J.ESM.2021.1.005","DOIUrl":"https://doi.org/10.5267/J.ESM.2021.1.005","url":null,"abstract":"The forming steps by permanent deformation controlled by the tools generate a distribution of stresses inside the material which directly depends on the work hardening properties of the latter. The change in boundary conditions following the removal of the tools imposes the material to redistribute the stresses in the sections in a manner compatible with the new boundary conditions. This new distribution necessarily operates by local elastic deformations that result globally in a general change of shape called springback. This geometrical deviation can be minimized by the meticulous focus of the tools, but it cannot generally be completely annihilated due to the influence of several parameters. For this reason, the study of the influence of the different technological factors and physico-metallurgical parameters on the springback for the different metals is very important to design and properly realize forming tools. The main objective of this work is to find solutions to problems encountered in sheet metal forming such as the problem of springback. Our work has two essential purposes: the first is summarized in an experimental study based on theoretical analyses. To this end, much effort is made to add a new design of parts for a U-type stretch-bending device and adapt it to a tensile testing machine. This design has the advantage of modifying and assembling all parameters affecting springback at the same time and also of carrying out several forming processes on the same device. The second goal is the experimental and numerical prediction of springback, and the study of the effect of various stretch-bending process parameters such as punch velocity, the orientation of the sheet (anisotropy), hold time and punch-die clearance on springback behavior under heat treatment of aluminum alloy sheets with three different rolling directions (0°,45°,90°). A finite element (FE) model of stretch-bending has been established by utilizing ABAQUS/CAE software. From this analysis, it can be concluded that the springback is affected by the anisotropy of the sheet and the heat treatment in the stretch-bending process. The obtained experimental results were compared with the numerical simulations found in good agreement.","PeriodicalId":37952,"journal":{"name":"Engineering Solid Mechanics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70759209","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 : 2021-01-01DOI: 10.5267/j.esm.2021.6.002
Tawanda Marazani, E. Akinlabi, D. Madyira, J. Majumdar, Surjya K. Pal
A 100% overlap double pass friction stir process technique was developed for the fabrication of AA1100/17-4 PH stainless steel composites, using an H13 tool steel cylindrical threaded pin with shoulder diameter of 21 mm, pin diameter of 7 mm and pin height of 5 mm. Grooves of 2 mm width and 3.5 mm depth were machined on the 6 mm thick AA1100 plate, where the 17-4 PH stainless steel powder was packed and compacted using a pinless tool. Friction stir processing was conducted at rotational speeds of 2100, 2450 and 2800 rpm, while the travel speed of 20 mm/min, tilt angle of 2.5° and plunge depth of 0.2 mm, were kept constant. Investigations were carried out on the microstructure, elemental composition, and tensile testing and microhardness as well as structural analysis using X-ray diffraction. Defect-free micrographs with good mechanical and metallurgical connections were obtained from all the employed process parameters. However, agglomeration of reinforcements became noticeable at 2450 and 2800 rpm. Uniform distribution of reinforcements were observed at 2100 rpm. Elemental analysis confirmed matrix and reinforcements blending and mixing. Superior SZ hardness of as high as 4 times that of the base metal were achieved, while ultimate tensile strength properties with joint efficiencies as high as 97.29% were attained at 2450 rpm. However, the percentage elongation of the fabricated samples dropped by around 10% due to the reinforcements-induced hardness. Nonetheless, the fabrications retained superior mechanical properties. All the X-ray diffractograms had 5 intense peaks with different phases and crystal planes. However, an Al syn (111) crystal plane was common to all diffractograms at around 39° 2θ range. The obtained crystallite sizes of as small as 4 nm revealed the attainment of ultrafine grains, while the observed high dislocation densities and micro strains gave an indication that the fabricated AA1100/17-4 PH stainless steel composite is of high strength.
{"title":"Microstructural, elemental, mechanical and structural attributes of AA1100/17-4 PH stainless steel composites fabricated via friction stir processing","authors":"Tawanda Marazani, E. Akinlabi, D. Madyira, J. Majumdar, Surjya K. Pal","doi":"10.5267/j.esm.2021.6.002","DOIUrl":"https://doi.org/10.5267/j.esm.2021.6.002","url":null,"abstract":"A 100% overlap double pass friction stir process technique was developed for the fabrication of AA1100/17-4 PH stainless steel composites, using an H13 tool steel cylindrical threaded pin with shoulder diameter of 21 mm, pin diameter of 7 mm and pin height of 5 mm. Grooves of 2 mm width and 3.5 mm depth were machined on the 6 mm thick AA1100 plate, where the 17-4 PH stainless steel powder was packed and compacted using a pinless tool. Friction stir processing was conducted at rotational speeds of 2100, 2450 and 2800 rpm, while the travel speed of 20 mm/min, tilt angle of 2.5° and plunge depth of 0.2 mm, were kept constant. Investigations were carried out on the microstructure, elemental composition, and tensile testing and microhardness as well as structural analysis using X-ray diffraction. Defect-free micrographs with good mechanical and metallurgical connections were obtained from all the employed process parameters. However, agglomeration of reinforcements became noticeable at 2450 and 2800 rpm. Uniform distribution of reinforcements were observed at 2100 rpm. Elemental analysis confirmed matrix and reinforcements blending and mixing. Superior SZ hardness of as high as 4 times that of the base metal were achieved, while ultimate tensile strength properties with joint efficiencies as high as 97.29% were attained at 2450 rpm. However, the percentage elongation of the fabricated samples dropped by around 10% due to the reinforcements-induced hardness. Nonetheless, the fabrications retained superior mechanical properties. All the X-ray diffractograms had 5 intense peaks with different phases and crystal planes. However, an Al syn (111) crystal plane was common to all diffractograms at around 39° 2θ range. The obtained crystallite sizes of as small as 4 nm revealed the attainment of ultrafine grains, while the observed high dislocation densities and micro strains gave an indication that the fabricated AA1100/17-4 PH stainless steel composite is of high strength.","PeriodicalId":37952,"journal":{"name":"Engineering Solid Mechanics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70760205","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 : 2021-01-01DOI: 10.5267/j.esm.2021.7.003
M. Nardo, Giuseppe Converso, Francesco Castagna, T. Murino
This paper aims to develop a maintenance optimization model to maintain a high level of efficiency and reliability of the machinery. The methodological approach is based on preventive maintenance through the partial or total replacement of critical components. Although an intermediate intervention control, the focus is on a particular machine that has stopped several times, reducing its operational availability and resulting in a high cost of non-production. This study uses a Weibull model to analyze and optimize the correct maintenance process of the machinery considered. The failure data are then analyzed and scheduled. The final purpose is to standardize the operators' intervention procedures to reduce the time for the same interventions.
{"title":"Development and implementation of an algorithm for preventive machine maintenance","authors":"M. Nardo, Giuseppe Converso, Francesco Castagna, T. Murino","doi":"10.5267/j.esm.2021.7.003","DOIUrl":"https://doi.org/10.5267/j.esm.2021.7.003","url":null,"abstract":"This paper aims to develop a maintenance optimization model to maintain a high level of efficiency and reliability of the machinery. The methodological approach is based on preventive maintenance through the partial or total replacement of critical components. Although an intermediate intervention control, the focus is on a particular machine that has stopped several times, reducing its operational availability and resulting in a high cost of non-production. This study uses a Weibull model to analyze and optimize the correct maintenance process of the machinery considered. The failure data are then analyzed and scheduled. The final purpose is to standardize the operators' intervention procedures to reduce the time for the same interventions.","PeriodicalId":37952,"journal":{"name":"Engineering Solid Mechanics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70760306","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 : 2021-01-01DOI: 10.5267/j.esm.2021.5.001
Derradji Lazhar, M. Toufik, Merzouki Tarek, Messai Abderraouf
An existing robust three dimensional finite element based on the strain approach is presented. This element is implemented, for the first time in the commercial computer code ABAQUS, by using the subroutine (UEL), for the static and dynamic analysis of isotropic plates, whatever thin or thick. It is Baptised SBH8 (Strain Based Hexahedral with 8 nodes) and has the advantage to overcome the problems involved in numerical locking, when the thickness of the plate tends towards the smallest values. The implementation is justified by the capacities broader than offers this code, especially, in the free frequencies computation. The results obtained by the present element are better than those given by elements used by ABAQUS code and the other elements found in the literature, having the same number of nodes.
{"title":"Solid strain based finite element implemented in ABAQUS for static and dynamic plate analysis","authors":"Derradji Lazhar, M. Toufik, Merzouki Tarek, Messai Abderraouf","doi":"10.5267/j.esm.2021.5.001","DOIUrl":"https://doi.org/10.5267/j.esm.2021.5.001","url":null,"abstract":"An existing robust three dimensional finite element based on the strain approach is presented. This element is implemented, for the first time in the commercial computer code ABAQUS, by using the subroutine (UEL), for the static and dynamic analysis of isotropic plates, whatever thin or thick. It is Baptised SBH8 (Strain Based Hexahedral with 8 nodes) and has the advantage to overcome the problems involved in numerical locking, when the thickness of the plate tends towards the smallest values. The implementation is justified by the capacities broader than offers this code, especially, in the free frequencies computation. The results obtained by the present element are better than those given by elements used by ABAQUS code and the other elements found in the literature, having the same number of nodes.","PeriodicalId":37952,"journal":{"name":"Engineering Solid Mechanics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70760322","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 : 2021-01-01DOI: 10.5267/j.esm.2021.5.003
A. Velychkovych, O. Bedzir, V. Shopa
The study presented herein describes promising designs of shell vibration isolators. The feature of the proposed designs is the cut thin-walled shell usage as the main bearing link. These resilient elements have high load capacity and, on the other hand, can provide the desired level of damping. From the point of view of mechanics, shell resilient elements are considered as the deformable systems with dry friction. When simulating these systems, structurally nonlinear non-conservative mixed contact issues of cut shell – resilient body frictional interaction arise. In order to take into account all essential options of the aforementioned issues and specify shell resilient element peculiarities of behavior under operational loads, the authors used the method of laboratory experiments for research. We considered two different contact systems. The first one is a cylindrical shell cut along its generatrix, which contacts a deformable filler. The second system is a cylindrical shell with several incomplete slots interacting with the elastic filler. The stress state and radial displacements of the shells, pliability of the resilient elements, and energy dissipation in the contact systems were time-tracked. As a result, we obtained relations for monitored options of the contact bodies and deformation diagrams for different physical-mechanical and geometrical options of the systems It was found that for a fixed cycle asymmetry coefficient with an increase in the friction coefficient between the shell and the filler, the amount of energy dissipated per cycle gradually decreases. The idea of optimizing shell vibration protection devices according to the criterion of maximum absorption of energy from external influences by determining the required tribological properties of contacting pairs is declared.
{"title":"Laboratory experimental study of contact interaction between cut shells and resilient bodies","authors":"A. Velychkovych, O. Bedzir, V. Shopa","doi":"10.5267/j.esm.2021.5.003","DOIUrl":"https://doi.org/10.5267/j.esm.2021.5.003","url":null,"abstract":"The study presented herein describes promising designs of shell vibration isolators. The feature of the proposed designs is the cut thin-walled shell usage as the main bearing link. These resilient elements have high load capacity and, on the other hand, can provide the desired level of damping. From the point of view of mechanics, shell resilient elements are considered as the deformable systems with dry friction. When simulating these systems, structurally nonlinear non-conservative mixed contact issues of cut shell – resilient body frictional interaction arise. In order to take into account all essential options of the aforementioned issues and specify shell resilient element peculiarities of behavior under operational loads, the authors used the method of laboratory experiments for research. We considered two different contact systems. The first one is a cylindrical shell cut along its generatrix, which contacts a deformable filler. The second system is a cylindrical shell with several incomplete slots interacting with the elastic filler. The stress state and radial displacements of the shells, pliability of the resilient elements, and energy dissipation in the contact systems were time-tracked. As a result, we obtained relations for monitored options of the contact bodies and deformation diagrams for different physical-mechanical and geometrical options of the systems It was found that for a fixed cycle asymmetry coefficient with an increase in the friction coefficient between the shell and the filler, the amount of energy dissipated per cycle gradually decreases. The idea of optimizing shell vibration protection devices according to the criterion of maximum absorption of energy from external influences by determining the required tribological properties of contacting pairs is declared.","PeriodicalId":37952,"journal":{"name":"Engineering Solid Mechanics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70760134","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 : 2021-01-01DOI: 10.5267/j.esm.2021.6.001
N. T. Tung
The braking force of the tractor semi-trailer depends on many random factors and road parameters. Therefore, determining the braking force based on theoretical calculation or simulation is not accurate. This paper presents the method of setting up the braking force measurement system of the tractor semi-trailer on the road and constructing the braking dynamics model of the tractor semi-trailer to investigate the braking force using Matlab-Simulink software. The study results show that the average error between the simulation and experimental results of the tractor semi-trailer braking force is 9,81%.
{"title":"Setting up the braking force measurement system of the tractor semi-trailer","authors":"N. T. Tung","doi":"10.5267/j.esm.2021.6.001","DOIUrl":"https://doi.org/10.5267/j.esm.2021.6.001","url":null,"abstract":"The braking force of the tractor semi-trailer depends on many random factors and road parameters. Therefore, determining the braking force based on theoretical calculation or simulation is not accurate. This paper presents the method of setting up the braking force measurement system of the tractor semi-trailer on the road and constructing the braking dynamics model of the tractor semi-trailer to investigate the braking force using Matlab-Simulink software. The study results show that the average error between the simulation and experimental results of the tractor semi-trailer braking force is 9,81%.","PeriodicalId":37952,"journal":{"name":"Engineering Solid Mechanics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70760171","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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