An optimal fast terminal sliding mode control strategy is proposed to suppress effectively the horizontal vibration of the high-speed elevator car system is caused by uncertainties such as rail unevenness, elevator load variation, and component friction and wear. Firstly, considering the elevator's composition structure and vibration characteristics, a 4-degree-of-freedom car system horizontal vibration active control model with a symmetric distribution of the control center is established. Secondly, considering the nonlinear factors of the rolling guide shoe and the external excitation, an optimal fast terminal sliding mode controller (PFTSMC) based on the sliding mode variable structure control is designed to eliminate the horizontal vibration of the car, define the nonsingular terminal sliding mode surface, and introduce the fast terminal convergence law based on the fast terminal attractor to ensure the accessibility of the sliding mode motion and reduce the jitter vibration. In addition, optimization of controller parameters using random weight particle swarm algorithm (RNW-PSO) to improve the controller's vibration suppression performance and robustness. Finally, the proposed controller can achieve more than 51.2% attenuation of horizontal vibration acceleration and displacement, showing that PFTSMC can effectively reduce the horizontal vibration of high-speed elevator car systems and improve ride comfort.
{"title":"Research on Optimal Fast Terminal Sliding Mode Control of Horizontal Vibration of High-speed Elevator Car System","authors":"Hua Li, Qin He, Li Li, Lixin Liu","doi":"10.1139/tcsme-2023-0055","DOIUrl":"https://doi.org/10.1139/tcsme-2023-0055","url":null,"abstract":"An optimal fast terminal sliding mode control strategy is proposed to suppress effectively the horizontal vibration of the high-speed elevator car system is caused by uncertainties such as rail unevenness, elevator load variation, and component friction and wear. Firstly, considering the elevator's composition structure and vibration characteristics, a 4-degree-of-freedom car system horizontal vibration active control model with a symmetric distribution of the control center is established. Secondly, considering the nonlinear factors of the rolling guide shoe and the external excitation, an optimal fast terminal sliding mode controller (PFTSMC) based on the sliding mode variable structure control is designed to eliminate the horizontal vibration of the car, define the nonsingular terminal sliding mode surface, and introduce the fast terminal convergence law based on the fast terminal attractor to ensure the accessibility of the sliding mode motion and reduce the jitter vibration. In addition, optimization of controller parameters using random weight particle swarm algorithm (RNW-PSO) to improve the controller's vibration suppression performance and robustness. Finally, the proposed controller can achieve more than 51.2% attenuation of horizontal vibration acceleration and displacement, showing that PFTSMC can effectively reduce the horizontal vibration of high-speed elevator car systems and improve ride comfort.","PeriodicalId":23285,"journal":{"name":"Transactions of The Canadian Society for Mechanical Engineering","volume":"201 3","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138997136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The fin-to-tube assembly is a prevalent connection type in heat exchangers, particularly in smaller equipment. During the assembly process, a die expands the tube to close the gap between the tube and the fin collar, enhancing heat transfer. The die expansion reduces the gap and creates slight interference that enables the fin collar to adhere to the tube. However, contact is not uniformly continuous across the width of the mating surfaces, as indicated by recent research. Due to this suboptimal contact quality, the conduction of heat is significantly impaired, and the efficiency of the heat exchanger is thus compromised. This study aims to establish a relationship between the profile shape of the fin hole and the contact quality, offering guidelines to enhance tube-to-fin contact. Tubes of various materials, dies of different sizes, and fins with a collar featuring an hourglass proposed shape are examined. The influence of a fin-hole hourglass shape will be assessed through a series of expansion simulations conducted on diverse finite element models. Subsequently, the micro-gaps formed during the expansion process at the tube-to-fin interface will serve to evaluate the quality of the contact surface, and a thermal transient analysis will be implemented to corroborate the findings.
{"title":"A Study on the Contact Quality Improvement of Fin to Tube Assemblies","authors":"Zijian Zhao, Hakim bouzid","doi":"10.1139/tcsme-2023-0062","DOIUrl":"https://doi.org/10.1139/tcsme-2023-0062","url":null,"abstract":"The fin-to-tube assembly is a prevalent connection type in heat exchangers, particularly in smaller equipment. During the assembly process, a die expands the tube to close the gap between the tube and the fin collar, enhancing heat transfer. The die expansion reduces the gap and creates slight interference that enables the fin collar to adhere to the tube. However, contact is not uniformly continuous across the width of the mating surfaces, as indicated by recent research. Due to this suboptimal contact quality, the conduction of heat is significantly impaired, and the efficiency of the heat exchanger is thus compromised. This study aims to establish a relationship between the profile shape of the fin hole and the contact quality, offering guidelines to enhance tube-to-fin contact. Tubes of various materials, dies of different sizes, and fins with a collar featuring an hourglass proposed shape are examined. The influence of a fin-hole hourglass shape will be assessed through a series of expansion simulations conducted on diverse finite element models. Subsequently, the micro-gaps formed during the expansion process at the tube-to-fin interface will serve to evaluate the quality of the contact surface, and a thermal transient analysis will be implemented to corroborate the findings.","PeriodicalId":23285,"journal":{"name":"Transactions of The Canadian Society for Mechanical Engineering","volume":"31 12","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139009943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper solves the problem of the precise compensation of the pose error of a 2TPR&2TPS parallel mechanism. First, the inverse solution of the mechanism is solved, the error source of the mechanism is analyzed, and a closed-loop vector method error model based on the inverse solution is established. Then, the ball screw commutation gap is measured with a high-precision grating ruler, and a laser tracker is used to measure the comprehensive position error of the mechanism under the set trajectory (circle). Finally, an error compensation algorithm based on the particle swarm algorithm is constructed, the measured trajectory data are substituted into the compensation algorithm, the position accuracy of the mechanism is significantly improved, and the compensation effect is remarkable. The compensation algorithm has good versatility, is simple and feasible, and can be applied to the error compensation of various mechanisms.
{"title":"ERROR COMPENSATION OF A 2TPR&2TPS PARALLEL MECHANISM BASED ON PARTICLE SWARM OPTIMIZATION","authors":"Chao He, Mingfang Chen, Hongjian Liang, Yongxia Zhang, Zhongping Chen","doi":"10.1139/tcsme-2023-0004","DOIUrl":"https://doi.org/10.1139/tcsme-2023-0004","url":null,"abstract":"This paper solves the problem of the precise compensation of the pose error of a 2TPR&2TPS parallel mechanism. First, the inverse solution of the mechanism is solved, the error source of the mechanism is analyzed, and a closed-loop vector method error model based on the inverse solution is established. Then, the ball screw commutation gap is measured with a high-precision grating ruler, and a laser tracker is used to measure the comprehensive position error of the mechanism under the set trajectory (circle). Finally, an error compensation algorithm based on the particle swarm algorithm is constructed, the measured trajectory data are substituted into the compensation algorithm, the position accuracy of the mechanism is significantly improved, and the compensation effect is remarkable. The compensation algorithm has good versatility, is simple and feasible, and can be applied to the error compensation of various mechanisms.","PeriodicalId":23285,"journal":{"name":"Transactions of The Canadian Society for Mechanical Engineering","volume":"42 45","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138588471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Latent heat thermal energy storage (LHTES) is particularly noteworthy thermal energy storage (TES) technology due to its high energy storage density. LHTES involves the use of phase change materials (PCMs) to store thermal energy, which can subsequently be used for heating and cooling applications as well as power generation. This paper outlines the techniques and tools employed to analyze existing literature on TES and LHTES systems research. Bibliometric, a statistical approach to analyzing written publications in specific fields of research, is used to identify significant findings and determine the course of scientific output. A strategic analysis of knowledge development is crucial for detecting opportunities and advancements within the field. This research offers valuable insights into the publication trends within the fields of TES and LHTES over the last three decades. Additionally, the study conducts a thorough examination of the geometric configurations of LHTES systems and their potential impacts on ongoing and future research. By tracking publication rates over thirty years, this study provides a comprehensive overview of how research in TES and LHTES has evolved. Understanding these trends helps researchers and policymakers gauge the growth and relevance of these fields in the context of energy storage and thermal management.
{"title":"Trends in Research on Latent Heat Storage Using PCM, A Bibliometric Analysis","authors":"Atif Shezad, Muhammad Tufail, Muhammad Uzair","doi":"10.1139/tcsme-2023-0093","DOIUrl":"https://doi.org/10.1139/tcsme-2023-0093","url":null,"abstract":"Latent heat thermal energy storage (LHTES) is particularly noteworthy thermal energy storage (TES) technology due to its high energy storage density. LHTES involves the use of phase change materials (PCMs) to store thermal energy, which can subsequently be used for heating and cooling applications as well as power generation. This paper outlines the techniques and tools employed to analyze existing literature on TES and LHTES systems research. Bibliometric, a statistical approach to analyzing written publications in specific fields of research, is used to identify significant findings and determine the course of scientific output. A strategic analysis of knowledge development is crucial for detecting opportunities and advancements within the field. This research offers valuable insights into the publication trends within the fields of TES and LHTES over the last three decades. Additionally, the study conducts a thorough examination of the geometric configurations of LHTES systems and their potential impacts on ongoing and future research. By tracking publication rates over thirty years, this study provides a comprehensive overview of how research in TES and LHTES has evolved. Understanding these trends helps researchers and policymakers gauge the growth and relevance of these fields in the context of energy storage and thermal management.","PeriodicalId":23285,"journal":{"name":"Transactions of The Canadian Society for Mechanical Engineering","volume":"61 24","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138605094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Counter Rotating Turbine (CRT) is considered as an alternative way of obtaining more work without the use of another guide vane in a multi-stage turbine. In such a scenario, present study discusses about the flow transmission that takes place in rotors, which are rotating in the reverse direction to each other. CRT stage with nozzle and rotors is modeled using ICEMCFD 14.5. Total pressure is specified at the inlet of turbine stage and flow rate is specified at the second rotor outlet. Contours of total pressure and turbulence kinetic energy provide the flow pattern in terms of steadiness, wake formation, incidence, flow circulation and flow turbulence. Velocity vectors and streamlines offer clarity about flow separation, vortex formation and wake detection. Deviation of flow characteristics from inlet to outlet of CRT stage are also presented. For further understanding of the flow, transverse planes at difference locations of the rotors are taken. Entropy and secondary velocity vectors are used to identify the loss aspect at each section of the rotors. From the blade-to-blade contours, the effect of absence of second guide vane is clear. Clearly, flow through rotor 1 is advantageous and flow through rotor 2 is chaotic.
{"title":"Comparison of Flow and Loss Aspects in the Rotors of a Counter Rotating Turbine","authors":"Subbarao Rayapati","doi":"10.1139/tcsme-2023-0100","DOIUrl":"https://doi.org/10.1139/tcsme-2023-0100","url":null,"abstract":"Counter Rotating Turbine (CRT) is considered as an alternative way of obtaining more work without the use of another guide vane in a multi-stage turbine. In such a scenario, present study discusses about the flow transmission that takes place in rotors, which are rotating in the reverse direction to each other. CRT stage with nozzle and rotors is modeled using ICEMCFD 14.5. Total pressure is specified at the inlet of turbine stage and flow rate is specified at the second rotor outlet. Contours of total pressure and turbulence kinetic energy provide the flow pattern in terms of steadiness, wake formation, incidence, flow circulation and flow turbulence. Velocity vectors and streamlines offer clarity about flow separation, vortex formation and wake detection. Deviation of flow characteristics from inlet to outlet of CRT stage are also presented. For further understanding of the flow, transverse planes at difference locations of the rotors are taken. Entropy and secondary velocity vectors are used to identify the loss aspect at each section of the rotors. From the blade-to-blade contours, the effect of absence of second guide vane is clear. Clearly, flow through rotor 1 is advantageous and flow through rotor 2 is chaotic.","PeriodicalId":23285,"journal":{"name":"Transactions of The Canadian Society for Mechanical Engineering","volume":"13 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139210941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Additive Manufacturing (AM) is considered an innovative technology to fabricate goods with green characteristics. In comparison to conventional manufacturing approaches, AM technologies have shown promising results in enhancing sustainability in production systems. Various research has been conducted to assess the environmental impacts of AM based on the well-known Life Cycle Assessment (LCA) framework. However, this approach requires intensive domain knowledge to build the environmental impact model and interpret the findings. This knowledge barrier may cause delays and challenges in the selection of the optimal design and process parameters for additively manufactured parts. Such challenges can be particularly prevalent during the early product design and planning stages. As such, the research community demands an automated LCA tool to support AM toward elevated sustainability. To achieve this ambitious goal, this paper particularly investi-gates the fundamental question – "What are the key influential parameters that pose an impact on the environmental sustainability of AM?". Thus, this paper proposes a methodological framework for identifying the key influential parameters for AM. The framework was demonstrated by taking the Fused Filament Fabrication process as a case study. Through instantiating various parts within the proposed framework and conducting LCA on over 200 AM instances, followed by correlation analysis, the key influential parameters were identified. Consequently, a data-driven predictive sustainability assessment and optimization framework was developed by integrating the identified influential features.
快速成型制造（AM）被认为是一种制造具有绿色特性产品的创新技术。与传统制造方法相比，AM 技术在提高生产系统的可持续性方面显示出良好的效果。基于众所周知的生命周期评估（LCA）框架，已经开展了各种研究来评估 AM 对环境的影响。然而，这种方法需要大量的领域知识来建立环境影响模型和解释研究结果。这种知识障碍可能会导致在为快速成型部件选择最佳设计和工艺参数时出现延误和挑战。这种挑战在早期产品设计和规划阶段尤为普遍。因此，研究界需要一种自动化的生命周期评估工具，以支持 AM 实现更高的可持续性。为了实现这一宏伟目标，本文特别探讨了一个基本问题--"哪些关键影响参数会对 AM 的环境可持续性产生影响？因此，本文提出了一个确定 AM 关键影响参数的方法框架。本文以熔融长丝制造工艺为例，对该框架进行了论证。通过在拟议框架内将各种部件实例化，并对 200 多个 AM 实例进行生命周期评估，然后进行相关性分析，确定了关键影响参数。因此，通过整合已确定的影响特征，开发出了数据驱动的预测性可持续性评估和优化框架。
{"title":"Feature selection and framework design toward data-driven predictive sustainability assessment and optimization for additive manufacturing","authors":"Ahmed Z Naser, F. Defersha, Sheng Yang","doi":"10.1139/tcsme-2023-0151","DOIUrl":"https://doi.org/10.1139/tcsme-2023-0151","url":null,"abstract":"Additive Manufacturing (AM) is considered an innovative technology to fabricate goods with green characteristics. In comparison to conventional manufacturing approaches, AM technologies have shown promising results in enhancing sustainability in production systems. Various research has been conducted to assess the environmental impacts of AM based on the well-known Life Cycle Assessment (LCA) framework. However, this approach requires intensive domain knowledge to build the environmental impact model and interpret the findings. This knowledge barrier may cause delays and challenges in the selection of the optimal design and process parameters for additively manufactured parts. Such challenges can be particularly prevalent during the early product design and planning stages. As such, the research community demands an automated LCA tool to support AM toward elevated sustainability. To achieve this ambitious goal, this paper particularly investi-gates the fundamental question – \"What are the key influential parameters that pose an impact on the environmental sustainability of AM?\". Thus, this paper proposes a methodological framework for identifying the key influential parameters for AM. The framework was demonstrated by taking the Fused Filament Fabrication process as a case study. Through instantiating various parts within the proposed framework and conducting LCA on over 200 AM instances, followed by correlation analysis, the key influential parameters were identified. Consequently, a data-driven predictive sustainability assessment and optimization framework was developed by integrating the identified influential features.","PeriodicalId":23285,"journal":{"name":"Transactions of The Canadian Society for Mechanical Engineering","volume":"2006 15","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139239405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Hopkins, Tim Clarke, Nam Nguyen, N. Z. Yussefian, Ali Hosseini
In milling operations, cutting tools are subjected to cyclic thermal and mechanical loads due to their intermittent engagement with the workpiece. As a result, they commonly fail due to edge chipping and thermal cracking, among which the former is directly related to the impact at the entry or exit, respectively, in downmilling or upmilling where the chip thickness is maximum. Among the many design factors that affect the impact resistance of milling tools, cutting-edge radius is one of the most important; however, it is often omitted in classic force models. In this paper, a force model that accounts for the edge radius was developed to predict the milling forces. Five sets of milling inserts with custom-made edge radii ranging from 25 to 45 µm were produced and tested. Test results were used to validate the force model and capture the effects of edge radius on the impact resistance of the prepared inserts. Results showed that increasing the edge radius initially improved the impact resistance and increased the tool life. However, increasing the edge radius beyond a certain threshold was proven to be detrimental since it made the tool blunt and drastically increased the cutting forces.
{"title":"On modelling the cutting forces and impact resistance of honed milling tools","authors":"C. Hopkins, Tim Clarke, Nam Nguyen, N. Z. Yussefian, Ali Hosseini","doi":"10.1139/tcsme-2023-0066","DOIUrl":"https://doi.org/10.1139/tcsme-2023-0066","url":null,"abstract":"In milling operations, cutting tools are subjected to cyclic thermal and mechanical loads due to their intermittent engagement with the workpiece. As a result, they commonly fail due to edge chipping and thermal cracking, among which the former is directly related to the impact at the entry or exit, respectively, in downmilling or upmilling where the chip thickness is maximum. Among the many design factors that affect the impact resistance of milling tools, cutting-edge radius is one of the most important; however, it is often omitted in classic force models. In this paper, a force model that accounts for the edge radius was developed to predict the milling forces. Five sets of milling inserts with custom-made edge radii ranging from 25 to 45 µm were produced and tested. Test results were used to validate the force model and capture the effects of edge radius on the impact resistance of the prepared inserts. Results showed that increasing the edge radius initially improved the impact resistance and increased the tool life. However, increasing the edge radius beyond a certain threshold was proven to be detrimental since it made the tool blunt and drastically increased the cutting forces.","PeriodicalId":23285,"journal":{"name":"Transactions of The Canadian Society for Mechanical Engineering","volume":"25 5","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139275552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sanjay Kumar, Muhammad Bilal, Saoud Sarwar, Zaheer Ahmed, Mujeeb Iqbal Soomro, Awais Junejo, Abdul Fatah Abbasi, Khanji Harijan
The flow field characteristics of non-circular turbulent jets are investigated numerically. A steady numerical simulation is conducted using the k-ε turbulence model in Ansys Fluent software. A hotwire anemometer is utilized to collect velocity data along the jet centerline for velocity validation. The jet exit Reynolds numbers are varied from 200 to 5000, covering both laminar and turbulent regimes. The mean flow field characteristics, such as mean velocity, turbulent intensity, velocity decay, and half jet spread width, are examined. The simulated results depict that mean velocity profile decay reveals a universal decay pattern, and the lateral velocity distribution show top-hat like velocity profile in the near field. It significantly changed into peak-shaped and parabolic-shaped at a far downstream distance. The turbulent intensity profile reveals that shear layer growth begins near the jet exits, and entrainment becomes strong with the Reynold number. The potential core region increases with Reynolds numbers. The jet spread width shows a linear increment with the jet exit Reynolds number. The presented numerical results agree well with the measured experimental results and are consistent with published data.
{"title":"NUMERICAL INVESTIGATION OF VELOCITY AND SPREADING CHARACTERISTICS OF NON-CIRCULAR TURBULENT JETS AT DIFFERENT REYNOLDS NUMBERS","authors":"Sanjay Kumar, Muhammad Bilal, Saoud Sarwar, Zaheer Ahmed, Mujeeb Iqbal Soomro, Awais Junejo, Abdul Fatah Abbasi, Khanji Harijan","doi":"10.1139/tcsme-2023-0028","DOIUrl":"https://doi.org/10.1139/tcsme-2023-0028","url":null,"abstract":"The flow field characteristics of non-circular turbulent jets are investigated numerically. A steady numerical simulation is conducted using the k-ε turbulence model in Ansys Fluent software. A hotwire anemometer is utilized to collect velocity data along the jet centerline for velocity validation. The jet exit Reynolds numbers are varied from 200 to 5000, covering both laminar and turbulent regimes. The mean flow field characteristics, such as mean velocity, turbulent intensity, velocity decay, and half jet spread width, are examined. The simulated results depict that mean velocity profile decay reveals a universal decay pattern, and the lateral velocity distribution show top-hat like velocity profile in the near field. It significantly changed into peak-shaped and parabolic-shaped at a far downstream distance. The turbulent intensity profile reveals that shear layer growth begins near the jet exits, and entrainment becomes strong with the Reynold number. The potential core region increases with Reynolds numbers. The jet spread width shows a linear increment with the jet exit Reynolds number. The presented numerical results agree well with the measured experimental results and are consistent with published data.","PeriodicalId":23285,"journal":{"name":"Transactions of The Canadian Society for Mechanical Engineering","volume":"75 S38","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135818131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wenrui Liu, Haotian Si, Cong Wang, Jianwei Sun, Tao Qin
A new objective function for optimizing spherical four-bar mechanisms for motion generation is presented. Rigid-body poses of a spherical four-bar mechanism in a standard installation position are investigated, and a normalization processing method is proposed. After processing the coupler points of the mechanism, the feature points generated are located on the circles. The formation principle of the feature coupler circles is analysed, and the internal relationship between the centre angle of the adjacent feature points on the feature coupler circles and the coupler angle of the spherical four-bar mechanism is determined. An input angle determination method is proposed for the spherical four-bar mechanism in a general installation position. An objective function is then established to optimize the basic dimensional types, relative input angles and installation position parameters of the desired spherical four-bar mechanism. The proposed method is applicable to both prescribed timing and unprescribed timing problems. Notably, the dimension of the optimization variables is only eight, which is exceptionally low for multiple position motion generation without prescribed timing; therefore, the global optimal solution is more easily obtained. The optimization process is carried out by the genetic algorithm. The feasibility and effectiveness of our proposed method are demonstrated by examples.
{"title":"Dimensional synthesis of motion generation of a spherical four-bar mechanism","authors":"Wenrui Liu, Haotian Si, Cong Wang, Jianwei Sun, Tao Qin","doi":"10.1139/tcsme-2023-0067","DOIUrl":"https://doi.org/10.1139/tcsme-2023-0067","url":null,"abstract":"A new objective function for optimizing spherical four-bar mechanisms for motion generation is presented. Rigid-body poses of a spherical four-bar mechanism in a standard installation position are investigated, and a normalization processing method is proposed. After processing the coupler points of the mechanism, the feature points generated are located on the circles. The formation principle of the feature coupler circles is analysed, and the internal relationship between the centre angle of the adjacent feature points on the feature coupler circles and the coupler angle of the spherical four-bar mechanism is determined. An input angle determination method is proposed for the spherical four-bar mechanism in a general installation position. An objective function is then established to optimize the basic dimensional types, relative input angles and installation position parameters of the desired spherical four-bar mechanism. The proposed method is applicable to both prescribed timing and unprescribed timing problems. Notably, the dimension of the optimization variables is only eight, which is exceptionally low for multiple position motion generation without prescribed timing; therefore, the global optimal solution is more easily obtained. The optimization process is carried out by the genetic algorithm. The feasibility and effectiveness of our proposed method are demonstrated by examples.","PeriodicalId":23285,"journal":{"name":"Transactions of The Canadian Society for Mechanical Engineering","volume":"91 S81","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135818675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rashique Iftekhar Rousseau, Hakim bouzid, Zijian Zhao
To address structural integrity of bolted joints and verify their capacity to withstand external loads and relaxation resulting from thermal expansion difference and creep, proper evaluation of the axial stiffnesses of bolt and clamped members are of vital importance. A number of finite element (FE) based methods are available for the calculation of the stiffnesses of joint elements, most of which rely on the displacement of arbitrarily selected nodes that has led to the improper evaluation of joint stiffness values. In this paper, the stiffness of clamped members is evaluated by a simple finite element methodology using a known bolt stiffness evaluated separately. Two load cases, one based on the application of external force (mechanical loading) and the other on temperature (thermal loading) are conducted using the FE method to validate the obtained results. The proposed methodology is also compared with other FE models and analytical methods obtained from literature. The new technique is based on an axisymmetric FE modeling and is applied to bolted joints with bolts ranging from M6 to M36 having various grip lengths. Finally, the stiffnesses of the bolt and clamped members can be determined accurately and a general formula is proposed to evaluate the stiffness of clamped members.
{"title":"On the re-evaluation of the clamped members stiffness of bolted joints","authors":"Rashique Iftekhar Rousseau, Hakim bouzid, Zijian Zhao","doi":"10.1139/tcsme-2023-0092","DOIUrl":"https://doi.org/10.1139/tcsme-2023-0092","url":null,"abstract":"To address structural integrity of bolted joints and verify their capacity to withstand external loads and relaxation resulting from thermal expansion difference and creep, proper evaluation of the axial stiffnesses of bolt and clamped members are of vital importance. A number of finite element (FE) based methods are available for the calculation of the stiffnesses of joint elements, most of which rely on the displacement of arbitrarily selected nodes that has led to the improper evaluation of joint stiffness values. In this paper, the stiffness of clamped members is evaluated by a simple finite element methodology using a known bolt stiffness evaluated separately. Two load cases, one based on the application of external force (mechanical loading) and the other on temperature (thermal loading) are conducted using the FE method to validate the obtained results. The proposed methodology is also compared with other FE models and analytical methods obtained from literature. The new technique is based on an axisymmetric FE modeling and is applied to bolted joints with bolts ranging from M6 to M36 having various grip lengths. Finally, the stiffnesses of the bolt and clamped members can be determined accurately and a general formula is proposed to evaluate the stiffness of clamped members.","PeriodicalId":23285,"journal":{"name":"Transactions of The Canadian Society for Mechanical Engineering","volume":"213 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135876186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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