The choke-level is one of the key factors that influence the falling process of the granular materials which is closely related to the crushing efficiency in the cone crusher. In this paper the motion characteristics of the particles near the choke-level have been analyzed and the phenomenon of single particle breakage below the choke level is pointed out. Based on the multi-zone method, an improved particle shape prediction model is established. In this model, the compound breaking behavior which includes the single particle breakage under the choke-level effect and the inter-particles breakage under the fill-feed, the transformation of particle shape and the particle size distribution in each crushing zone are considered. Tests on the PYG-B1735 cone crusher are conducted in order to validate the improved model. The improved model provides a theoretical foundation for the productivity estimation and the performance optimization.
{"title":"The Improved Model of Particle Shape Prediction Considering the Choke-Level Effect for Cone Crusher","authors":"Zhang Wei, Wang Jixin, Yun Xiangjun","doi":"10.1115/IMECE2018-88603","DOIUrl":"https://doi.org/10.1115/IMECE2018-88603","url":null,"abstract":"The choke-level is one of the key factors that influence the falling process of the granular materials which is closely related to the crushing efficiency in the cone crusher. In this paper the motion characteristics of the particles near the choke-level have been analyzed and the phenomenon of single particle breakage below the choke level is pointed out. Based on the multi-zone method, an improved particle shape prediction model is established. In this model, the compound breaking behavior which includes the single particle breakage under the choke-level effect and the inter-particles breakage under the fill-feed, the transformation of particle shape and the particle size distribution in each crushing zone are considered. Tests on the PYG-B1735 cone crusher are conducted in order to validate the improved model. The improved model provides a theoretical foundation for the productivity estimation and the performance optimization.","PeriodicalId":201128,"journal":{"name":"Volume 13: Design, Reliability, Safety, and Risk","volume":"157 9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128821421","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}
R. Shanmugam, Uma Vellaisamy, K. Balasubramaniam, Sathishkumar Mani
In hot summer, the sun rays strike the roof surface and heat up the enclosed attic. Passive vents (Soffit or Gable) allow some circulation of fresh air. Presently, in India, passive Whirlybird is predominantly used for ventilation purposes, which spins and sucks up the warm air and forces it out upwards through the vent on the roof. Since it depends mainly on the natural wind velocity, it’s efficiency to cost ratio is very low. Also, the accumulation of dust particles has a deleterious effect on the performance and life of the unit. Hence, in this work, a roof top solar ventilator has been designed and developed at low cost to address the above-mentioned problems. This unit has a high-performance brushless DC motor, an adjustable solar panel to achieve optimal solar exposure and it blends seamlessly into roof. The solar panel powers the fan through the motor, thereby increasing the air circulation through the vent. This increased air circulation provides the required pressure to force the hot air out from the attic. During hot summer, the difference in temperature between the floor and the ceiling can reach 10–15 °C, leading to a constant heat pile up in the attic and this system can limit the temperature of the attic to 40°C. In winter season, moist air present inside the house warms up, rises and collides with the cold air entering through the roof. This provides a mixed circulation that prevents the cold air from entering the roof and also reduces freezing of snow on the roof surface. Further, it keeps the inside space cooler and drier. Since this ventilator operates on renewable energy source, it is a simple and feasible solution that is environmentally friendly at low-cost. This provides healthy, energy efficient homes and work spaces as it reduces the usage of air conditions and heaters. A comparative study on the performance, life and cost of both the existing and the newly developed ventilators has been made and the same is reported.
{"title":"Design and Development of a Low-Cost Roof Top Solar Ventilator","authors":"R. Shanmugam, Uma Vellaisamy, K. Balasubramaniam, Sathishkumar Mani","doi":"10.1115/IMECE2018-86997","DOIUrl":"https://doi.org/10.1115/IMECE2018-86997","url":null,"abstract":"In hot summer, the sun rays strike the roof surface and heat up the enclosed attic. Passive vents (Soffit or Gable) allow some circulation of fresh air. Presently, in India, passive Whirlybird is predominantly used for ventilation purposes, which spins and sucks up the warm air and forces it out upwards through the vent on the roof. Since it depends mainly on the natural wind velocity, it’s efficiency to cost ratio is very low. Also, the accumulation of dust particles has a deleterious effect on the performance and life of the unit. Hence, in this work, a roof top solar ventilator has been designed and developed at low cost to address the above-mentioned problems. This unit has a high-performance brushless DC motor, an adjustable solar panel to achieve optimal solar exposure and it blends seamlessly into roof. The solar panel powers the fan through the motor, thereby increasing the air circulation through the vent. This increased air circulation provides the required pressure to force the hot air out from the attic. During hot summer, the difference in temperature between the floor and the ceiling can reach 10–15 °C, leading to a constant heat pile up in the attic and this system can limit the temperature of the attic to 40°C. In winter season, moist air present inside the house warms up, rises and collides with the cold air entering through the roof. This provides a mixed circulation that prevents the cold air from entering the roof and also reduces freezing of snow on the roof surface. Further, it keeps the inside space cooler and drier. Since this ventilator operates on renewable energy source, it is a simple and feasible solution that is environmentally friendly at low-cost. This provides healthy, energy efficient homes and work spaces as it reduces the usage of air conditions and heaters. A comparative study on the performance, life and cost of both the existing and the newly developed ventilators has been made and the same is reported.","PeriodicalId":201128,"journal":{"name":"Volume 13: Design, Reliability, Safety, and Risk","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129778517","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}
Spring operated pressure relief valves (SOPRVs) are essential components of technical systems. As parts of safety systems, they protect people and the environment from technological hazards. Their ability to open at a predefined pressure is considered the most important feature. The reliability of this function depends on numerous operational and design factors. In this paper, we examine the effects of design measures on the mechanical loads in seat seals of SOPRVs. In particular, we evaluate the applicability of the principle of non-uniform system stiffness in order to systematically control the mechanical loads in seat seals for an exemplary case of a flat faced soft seated SOPRV. We systematically vary design parameters and accurately estimate the contact stresses as well as the set pressure by performing non-linear finite element analyses. We focus on the quasi-static case of a closed seal, since dynamic effects of the opening and closing processes are not within the scope of this work. In our contribution, we show that the application of these design measures can significantly influence both the initial contact stresses and the set pressure at a constant spring force. In particular, the effects of the taper angle are analyzed and discussed.
{"title":"Systematic Study of the Effect of Non-Uniform Seal Stiffness on the Contact Stress in Flat-Faced Soft-Seated Spring Operated Pressure Relief Valves","authors":"Alex Schimanowski, A. Seibel, J. Schlattmann","doi":"10.1115/IMECE2018-87926","DOIUrl":"https://doi.org/10.1115/IMECE2018-87926","url":null,"abstract":"Spring operated pressure relief valves (SOPRVs) are essential components of technical systems. As parts of safety systems, they protect people and the environment from technological hazards. Their ability to open at a predefined pressure is considered the most important feature. The reliability of this function depends on numerous operational and design factors.\u0000 In this paper, we examine the effects of design measures on the mechanical loads in seat seals of SOPRVs. In particular, we evaluate the applicability of the principle of non-uniform system stiffness in order to systematically control the mechanical loads in seat seals for an exemplary case of a flat faced soft seated SOPRV. We systematically vary design parameters and accurately estimate the contact stresses as well as the set pressure by performing non-linear finite element analyses. We focus on the quasi-static case of a closed seal, since dynamic effects of the opening and closing processes are not within the scope of this work. In our contribution, we show that the application of these design measures can significantly influence both the initial contact stresses and the set pressure at a constant spring force. In particular, the effects of the taper angle are analyzed and discussed.","PeriodicalId":201128,"journal":{"name":"Volume 13: Design, Reliability, Safety, and Risk","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126259932","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}
U. Etxeberria, J. A. Esnaola, I. Ulacia, D. Ugarte, I. Llavori, M. Larrañaga, A. Lopez-Jauregi
Tensile residual stress (RS) peaks near the weld toe accelerate crack generation and propagation stages reducing dramatically the life of welded components. In order to relief RS, components are typically heat-treated. However, heat treatments can affect the microstructure compromising mechanical properties. In addition, their application in big structures is complex due to size limitations. As an alternative, mechanical treatments such as shot peening can be locally applied. Moreover, they generate local compressive stresses in the treated surfaces, which present beneficial effect in the fatigue strength of treated components. In the present work, the contribution of shot peening in the fatigue strength of multipass welded joints is numerically evaluated. For that purpose, first the RS stress pattern of a 3 pass butt weld of 10mm thick, 50mm length S275JR plates is calculated. Following, the application of shot peening in the tensile RS area is modelled and the evolution of RS pattern is analyzed. Finally, the fatigue strength of treated and non-treated butt welds is evaluated.
{"title":"Numerical Analysis of the Contribution of Shot Peening in the Fatigue Strength of Multipass Welded Joints","authors":"U. Etxeberria, J. A. Esnaola, I. Ulacia, D. Ugarte, I. Llavori, M. Larrañaga, A. Lopez-Jauregi","doi":"10.1115/IMECE2018-87720","DOIUrl":"https://doi.org/10.1115/IMECE2018-87720","url":null,"abstract":"Tensile residual stress (RS) peaks near the weld toe accelerate crack generation and propagation stages reducing dramatically the life of welded components. In order to relief RS, components are typically heat-treated. However, heat treatments can affect the microstructure compromising mechanical properties. In addition, their application in big structures is complex due to size limitations. As an alternative, mechanical treatments such as shot peening can be locally applied. Moreover, they generate local compressive stresses in the treated surfaces, which present beneficial effect in the fatigue strength of treated components.\u0000 In the present work, the contribution of shot peening in the fatigue strength of multipass welded joints is numerically evaluated. For that purpose, first the RS stress pattern of a 3 pass butt weld of 10mm thick, 50mm length S275JR plates is calculated. Following, the application of shot peening in the tensile RS area is modelled and the evolution of RS pattern is analyzed. Finally, the fatigue strength of treated and non-treated butt welds is evaluated.","PeriodicalId":201128,"journal":{"name":"Volume 13: Design, Reliability, Safety, and Risk","volume":"291 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124193596","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}
Given the current trend in manufacturing to decrease part variability, and in order to increase product quality, dimensional tolerances are becoming more exacting. With this in mind, and with the decreased time allotted for components to progress from design to manufacture, it has become more critical that accurate models of the manufacturing process are developed. This paper investigates the changes in cross sectional area when a prismatic bar is plastically deformed into a ring of constant diameter. Through further processing, these rings are transformed into components that function to secure mechanical components, such as bearings, into assemblies. Failure of the ring can cause significant damage, or failure of the assembly. Typical thickness tolerances are on the order of +/−.002” (0.05 mm), but can be as small as +/−.0002” (0.005 mm). Also, a growing trend in manufacturing is for the final ring to have a specified thickness on the inner and outer edge within this tolerance band. The rings are produced in various metallic materials with different mechanical properties by continuously coiling prismatic bars to a specific diameter. An analytic model based on small strain theory was developed for the simple cross sections of rectangular and trapezoidal geometries. This model was then extended to include the effect of a hyperbolic rather than linear stress distribution through this simple section in order to relieve the constraints of small strain theory and adequately model the actual process. An empirical model was developed based on experimental observations. A numerical model was developed using the commercial finite element analysis (FEA) software Abaqus (SIMULIA, Providence, RI) to simulate the manufacturing process. This was compared to the empirical model developed from production parts for validation. Once the finite element model is validated, it could be used to explore the effects of design parameters (initial dimensions of the prismatic bar, material properties etc.) and create efficient designs for manufacturing. The empirical model can then be used in the design process. Additionally, the numerical simulation could be used to model more complex cross sectional areas which cannot be evaluated analytically. There was adequate agreement between the empirical and numerical models to the extent that the numerical model could be used for more complex cross sectional geometries. A further refinement of the analytic model to include finite strain theory should be used to expand on this.
{"title":"Cross Sectional Area Changes due to Plastic Bending of Prismatic Bars","authors":"M. Zielinski, I. S. Cinoglu","doi":"10.1115/IMECE2018-87608","DOIUrl":"https://doi.org/10.1115/IMECE2018-87608","url":null,"abstract":"Given the current trend in manufacturing to decrease part variability, and in order to increase product quality, dimensional tolerances are becoming more exacting. With this in mind, and with the decreased time allotted for components to progress from design to manufacture, it has become more critical that accurate models of the manufacturing process are developed. This paper investigates the changes in cross sectional area when a prismatic bar is plastically deformed into a ring of constant diameter. Through further processing, these rings are transformed into components that function to secure mechanical components, such as bearings, into assemblies. Failure of the ring can cause significant damage, or failure of the assembly. Typical thickness tolerances are on the order of +/−.002” (0.05 mm), but can be as small as +/−.0002” (0.005 mm). Also, a growing trend in manufacturing is for the final ring to have a specified thickness on the inner and outer edge within this tolerance band. The rings are produced in various metallic materials with different mechanical properties by continuously coiling prismatic bars to a specific diameter. An analytic model based on small strain theory was developed for the simple cross sections of rectangular and trapezoidal geometries. This model was then extended to include the effect of a hyperbolic rather than linear stress distribution through this simple section in order to relieve the constraints of small strain theory and adequately model the actual process. An empirical model was developed based on experimental observations. A numerical model was developed using the commercial finite element analysis (FEA) software Abaqus (SIMULIA, Providence, RI) to simulate the manufacturing process. This was compared to the empirical model developed from production parts for validation. Once the finite element model is validated, it could be used to explore the effects of design parameters (initial dimensions of the prismatic bar, material properties etc.) and create efficient designs for manufacturing. The empirical model can then be used in the design process. Additionally, the numerical simulation could be used to model more complex cross sectional areas which cannot be evaluated analytically. There was adequate agreement between the empirical and numerical models to the extent that the numerical model could be used for more complex cross sectional geometries. A further refinement of the analytic model to include finite strain theory should be used to expand on this.","PeriodicalId":201128,"journal":{"name":"Volume 13: Design, Reliability, Safety, and Risk","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115650269","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}
Yunlei Yin, Wenxiang Dong, Zhenfei Zhan, Junming Li
The mesh morphing method is widely applied in building subject-specific human finite element models. However, there are many problems yet to be resolved when applying the mesh morphing method in subject-specific modeling, such as calculation difficulties and low morphing accuracy. To solve these problems above, an efficient peak-selection RBF mesh morphing method is proposed in the paper. Firstly, by comparing different types of radial basis functions, an optimal kernel function is selected to improve morphing accuracy. Secondly, the landmarks are reduced by selecting multiple peak nodes from the object surfaces, so as to reduce iteration steps and improve the mesh generation efficiency. The proposed peak-selection Radial Basis Function (RBF) mesh morphing method is further demonstrated through a subject-specific child finite element modeling problem. This mesh morphing method has important significance for analyzing the occupant injury of different body features in motor vehicle crashes.
{"title":"A Peak-Selection RBF Mesh Morphing Method for Subject-Specific Child Occupant Modeling","authors":"Yunlei Yin, Wenxiang Dong, Zhenfei Zhan, Junming Li","doi":"10.1115/IMECE2018-88398","DOIUrl":"https://doi.org/10.1115/IMECE2018-88398","url":null,"abstract":"The mesh morphing method is widely applied in building subject-specific human finite element models. However, there are many problems yet to be resolved when applying the mesh morphing method in subject-specific modeling, such as calculation difficulties and low morphing accuracy. To solve these problems above, an efficient peak-selection RBF mesh morphing method is proposed in the paper. Firstly, by comparing different types of radial basis functions, an optimal kernel function is selected to improve morphing accuracy. Secondly, the landmarks are reduced by selecting multiple peak nodes from the object surfaces, so as to reduce iteration steps and improve the mesh generation efficiency. The proposed peak-selection Radial Basis Function (RBF) mesh morphing method is further demonstrated through a subject-specific child finite element modeling problem. This mesh morphing method has important significance for analyzing the occupant injury of different body features in motor vehicle crashes.","PeriodicalId":201128,"journal":{"name":"Volume 13: Design, Reliability, Safety, and Risk","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128678814","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}
H. Mendes, C. Coutinho, S. Tavares, Luís M. R. Félix, A. Matos, J. Meireles, A. Pinho, Joel R. S. Teixeira
Even though the power transformers are electrical machines, their design includes several important steps with strong emphasis on mechanical engineering topics, such as the design of welded metallic structures. Indeed, the tank and its cover are typically manufactured from steel sheets or plates to which a group of stiffeners are added, with the objective of reducing the bending stress, transverse displacements and/or buckling. The current communication presents and discusses several incremental innovations in the structural design and simulation of tanks for Core type power transformers, including: (i) optimization of the stiffeners design and welding bead volume reduction; (ii) optimization of panels curvature; (iii) simulation of the transformer tank loaded by both hydrostatic pressure and vacuum conditions; and (iv) inclusion of non-linear behavior to more accurately simulate representative structures. Achieved numerical results are compared with obtained experimental data, to evaluate the design procedures and the potential of virtual testing of new solutions.
{"title":"Advanced Modeling and Experimental Validation of an Optimized Power Transformer Tank","authors":"H. Mendes, C. Coutinho, S. Tavares, Luís M. R. Félix, A. Matos, J. Meireles, A. Pinho, Joel R. S. Teixeira","doi":"10.1115/IMECE2018-87769","DOIUrl":"https://doi.org/10.1115/IMECE2018-87769","url":null,"abstract":"Even though the power transformers are electrical machines, their design includes several important steps with strong emphasis on mechanical engineering topics, such as the design of welded metallic structures. Indeed, the tank and its cover are typically manufactured from steel sheets or plates to which a group of stiffeners are added, with the objective of reducing the bending stress, transverse displacements and/or buckling.\u0000 The current communication presents and discusses several incremental innovations in the structural design and simulation of tanks for Core type power transformers, including: (i) optimization of the stiffeners design and welding bead volume reduction; (ii) optimization of panels curvature; (iii) simulation of the transformer tank loaded by both hydrostatic pressure and vacuum conditions; and (iv) inclusion of non-linear behavior to more accurately simulate representative structures.\u0000 Achieved numerical results are compared with obtained experimental data, to evaluate the design procedures and the potential of virtual testing of new solutions.","PeriodicalId":201128,"journal":{"name":"Volume 13: Design, Reliability, Safety, and Risk","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129022647","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}
Kaitlyn N. Fritz, Line Deschenes, Vijitashwa Pandey
Engineering design is typically a team effort. Design teams frequently need to push technical boundaries to solve the most relevant challenges faced by our society. A significant area of research across multiple fields of investigation, including engineering, is the understanding and use of an individual’s cognitive attributes in the process of assembling productive teams. This research proposes an approach to assembling an engineering design team by first defining the desirable cognitive attributes in the team members. Subsequently, based on individual cognitive profile assessments along these attributes, an exhaustive list of possible design teams is investigated based on their cumulative attribute level. We compare the performance of two teams predicted to perform at different levels, and our results verify the differences between the observations of team interactions and the quality of designs produced. In addition to self-assessments, we also investigate the brain activity of the respondents using electroencephalography (EEG) to evaluate performance in an individual and a team setting. This analysis intends to highlight the characteristics of an individuals’ brain activity under different circumstances to reveal if these characteristics contribute to the success of a design team. EEG data revealed observations such as correlation between raw amplitude and level of team contribution, a higher variation in the channel power spectral density during individual versus team tasks, and a degradation of alpha activity moving from individual to group work. The results of this research can guide organizations to form teams with the necessary cognitive attributes to achieve the optimum design solution.
{"title":"Effective Design Team Composition Using Individual and Group Cognitive Attributes","authors":"Kaitlyn N. Fritz, Line Deschenes, Vijitashwa Pandey","doi":"10.1115/IMECE2018-86888","DOIUrl":"https://doi.org/10.1115/IMECE2018-86888","url":null,"abstract":"Engineering design is typically a team effort. Design teams frequently need to push technical boundaries to solve the most relevant challenges faced by our society. A significant area of research across multiple fields of investigation, including engineering, is the understanding and use of an individual’s cognitive attributes in the process of assembling productive teams. This research proposes an approach to assembling an engineering design team by first defining the desirable cognitive attributes in the team members. Subsequently, based on individual cognitive profile assessments along these attributes, an exhaustive list of possible design teams is investigated based on their cumulative attribute level. We compare the performance of two teams predicted to perform at different levels, and our results verify the differences between the observations of team interactions and the quality of designs produced. In addition to self-assessments, we also investigate the brain activity of the respondents using electroencephalography (EEG) to evaluate performance in an individual and a team setting. This analysis intends to highlight the characteristics of an individuals’ brain activity under different circumstances to reveal if these characteristics contribute to the success of a design team. EEG data revealed observations such as correlation between raw amplitude and level of team contribution, a higher variation in the channel power spectral density during individual versus team tasks, and a degradation of alpha activity moving from individual to group work. The results of this research can guide organizations to form teams with the necessary cognitive attributes to achieve the optimum design solution.","PeriodicalId":201128,"journal":{"name":"Volume 13: Design, Reliability, Safety, and Risk","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116389109","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}
Tyler Stranburg, Yucheng Liu, H. Chander, A. Knight
A nitinol-based arch wedge support (AWS) was designed using computational approach. Finite element analysis (FEA) was performed to on this design to assess the influence of loading, boundary conditions, and thickness on the mechanical response of the computer-aid design (CAD) model. Five loading conditions caused by different human movements, two boundary conditions, and three thicknesses are involved in this computational study. FEA results showed that the presented AWS design can resist forces caused by different human motions without generating any permanent deformation. The study features the first time to design and evaluate a thin-walled nitinol AWS model. The results of this study form the background of prototyping and experimental testing of the design in the next phase.
{"title":"Computational Design and Analysis of Nitinol-Based Arch Wedge Support","authors":"Tyler Stranburg, Yucheng Liu, H. Chander, A. Knight","doi":"10.1115/IMECE2018-86287","DOIUrl":"https://doi.org/10.1115/IMECE2018-86287","url":null,"abstract":"A nitinol-based arch wedge support (AWS) was designed using computational approach. Finite element analysis (FEA) was performed to on this design to assess the influence of loading, boundary conditions, and thickness on the mechanical response of the computer-aid design (CAD) model. Five loading conditions caused by different human movements, two boundary conditions, and three thicknesses are involved in this computational study. FEA results showed that the presented AWS design can resist forces caused by different human motions without generating any permanent deformation. The study features the first time to design and evaluate a thin-walled nitinol AWS model. The results of this study form the background of prototyping and experimental testing of the design in the next phase.","PeriodicalId":201128,"journal":{"name":"Volume 13: Design, Reliability, Safety, and Risk","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128196331","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}
F. Mahdavi, I. Hossain, H. Hayati, D. Eager, Paul J. Kennedy
A challenge for greyhound racing is optimizing the tracks to minimize the risk of injuries. The effects of different track design variables on greyhound injury rates has not been explored sufficiently. The purpose of this paper is to present some preliminary findings on the effect of greyhound racetrack design variables such as the track curvature and lure alignment. An analysis was carried out of two years of greyhound racing injury data from three different tracks in New South Wales, Australia. The data from before and after an intervention was introduced were compared. Variables in the study, which may affect the analysis were investigated to minimize the errors. The analysis showed that there is a reduction in injury rates for a longer lure arm in the tracks with short or no straight section. To verify the effect of track design variables on the greyhound dynamics a kinematic simulation of greyhound center of gravity was created. The simulation considered fundamental variables correlating directly with kinematics between the greyhound and the track. The simulation data showed that the rate of change in the rotation of the greyhound heading direction decreases when the track running path has a more gradual curvature. The result of the simulation showed excellent agreement with that of injury data analysis.
{"title":"Track Shape, Resulting Dynamics and Injury Rates of Greyhounds","authors":"F. Mahdavi, I. Hossain, H. Hayati, D. Eager, Paul J. Kennedy","doi":"10.1115/IMECE2018-87156","DOIUrl":"https://doi.org/10.1115/IMECE2018-87156","url":null,"abstract":"A challenge for greyhound racing is optimizing the tracks to minimize the risk of injuries. The effects of different track design variables on greyhound injury rates has not been explored sufficiently. The purpose of this paper is to present some preliminary findings on the effect of greyhound racetrack design variables such as the track curvature and lure alignment. An analysis was carried out of two years of greyhound racing injury data from three different tracks in New South Wales, Australia. The data from before and after an intervention was introduced were compared. Variables in the study, which may affect the analysis were investigated to minimize the errors. The analysis showed that there is a reduction in injury rates for a longer lure arm in the tracks with short or no straight section.\u0000 To verify the effect of track design variables on the greyhound dynamics a kinematic simulation of greyhound center of gravity was created. The simulation considered fundamental variables correlating directly with kinematics between the greyhound and the track. The simulation data showed that the rate of change in the rotation of the greyhound heading direction decreases when the track running path has a more gradual curvature. The result of the simulation showed excellent agreement with that of injury data analysis.","PeriodicalId":201128,"journal":{"name":"Volume 13: Design, Reliability, Safety, and Risk","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129270359","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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