Intelligent optimization algorithm belongs to a kind of emerging technology,show good characteristics,such as high performance,applicability,its algorithm includes many contents,including genetic,particle swarm and ar...Intelligent optimization algorithm belongs to a kind of emerging technology,show good characteristics,such as high performance,applicability,its algorithm includes many contents,including genetic,particle swarm and artificial neural network algorithm,compared with the traditional optimization way,these algorithms can be applied to a variety of situations,meet the demand of solution,in the mechanical design industry has wide application prospects.This paper analyzes the application of the algorithm in mechanical design and the comparison of the results to verify the significance of the intelligent optimization algorithm in mechanical design.展开更多
A servo press is a new type of mechanical press that is driven by programmable motors and offers superior performance such as low noise, excellent efficiency and high precision for metal forming operations. Similar to...A servo press is a new type of mechanical press that is driven by programmable motors and offers superior performance such as low noise, excellent efficiency and high precision for metal forming operations. Similar to multi-link mechanical presses, a servo mechanical press tends to grow in size as the tonnage increases that calls for larger, heavy duty servo motors, which could be expensive and may not even be available. In this paper, a new concept of servo mechanical press with redundant actuation is proposed firstly using two servo motors driving one input shaft, i.e. one-point-two-motor mode that makes it possible to produce a larger press with available servomotors. Then the punching mechanism design is detailed. The performance indices are set up including mechanical advantage reciprocal and link force ratios. A bounded feasible solution space is constructed for dimensional synthesis based on non-dimensional link lengths and assembly conditions. The performance atlases are depicted over the bounded feasible solution space that lead to a visual solution of the punching mechanism with global optimization. Finally, case studies are given to illustrate the design method with visual global optimization, and a prototype with 200 t punching force is being developed in our laboratory to demonstrate efficacy of the new concept for servo mechanical press. The presented research provides a feasible solution to the development of heavy-duty servo mechanical presses and finds potential applications in the development of other types of heavy equipments with electric drive.展开更多
A novel hybrid algorithm named ABC-BBO, which integrates artificial bee colony(ABC) algorithm with biogeography-based optimization(BBO) algorithm, is proposed to solve constrained mechanical design problems. ABC-BBO c...A novel hybrid algorithm named ABC-BBO, which integrates artificial bee colony(ABC) algorithm with biogeography-based optimization(BBO) algorithm, is proposed to solve constrained mechanical design problems. ABC-BBO combined the exploration of ABC algorithm with the exploitation of BBO algorithm effectively, and hence it can generate the promising candidate individuals. The proposed hybrid algorithm speeds up the convergence and improves the algorithm's performance. Several benchmark test functions and mechanical design problems are applied to verifying the effects of these improvements and it is demonstrated that the performance of this proposed ABC-BBO is superior to or at least highly competitive with other population-based optimization approaches.展开更多
A kind of automatic shift schedule optimization method is provided for a tracked vehicle with hydrodynamic-mechanical transmission in order to improve its dynamic performance. A dynamic model of integrated hydrodynami...A kind of automatic shift schedule optimization method is provided for a tracked vehicle with hydrodynamic-mechanical transmission in order to improve its dynamic performance. A dynamic model of integrated hydrodynamic-mechanical transmission is built in MATLAB/Simdriveline environment, and an optimum shift schedule is derived by using iSight software to call the dynamic model above, then the shift schedule is achieved after optimization. The simulation results show that the method is significant to improve the dynamic performance and gear-shifting smoothness theoretically and practically.展开更多
Erratum to:International Journal of Minerals, Metallurgy and Materials Volume 26, Number 9, September 2019, Page 1151https://doi.org/10.1007/s12613-019-1854-1The original version of this article unfortunately containe...Erratum to:International Journal of Minerals, Metallurgy and Materials Volume 26, Number 9, September 2019, Page 1151https://doi.org/10.1007/s12613-019-1854-1The original version of this article unfortunately contained a mistake. The presentation of Fig. 11 was incorrect. The correct version is given below:展开更多
In this paper, a Web-based Mechanical Design and A na lysis Framework (WMDAF) is proposed. This WMADF allows designers to develop web -based computer aided programs in a systematic way during the collaborative mec han...In this paper, a Web-based Mechanical Design and A na lysis Framework (WMDAF) is proposed. This WMADF allows designers to develop web -based computer aided programs in a systematic way during the collaborative mec hanical system design and analysis process. This system is based on an emerg ing web-based Content Management System (CMS) called eXtended Object Oriented P ortal System (XOOPS). Due to the Open Source Status of the XOOPS CMS, programs d eveloped with this framework can be further customized to satisfy the demands of the user. To introduce the use of this framework, this paper exams three differ ent types of mechanical design and analysis problems. First, a repetitive design consideration and calculation process is transferred into WMADF programs to gai n efficiency for wired collaborative team. Second, the considered product solid model is created directly through the use of XOOPS program and Microsoft Compone nt Object Model (COM) instances. To the end of the paper, an example linked with ANSYS is used to indicate the possible application of this framework.展开更多
The concept of Intelligent Mechanical Design (IMD) is presented to show how a mechanical structure can be designed to affect robot controllability, simplification and task performance. Exploring this concept produce...The concept of Intelligent Mechanical Design (IMD) is presented to show how a mechanical structure can be designed to affect robot controllability, simplification and task performance. Exploring this concept produces landmarks in the territory of mechanical robot design in the form of seven design principles. The design principles, which we call the Mecha-Telligence Principles (MTP), provide guidance on how to design mechanics for autonomous mobile robots. These principles guide us to ask the right questions when investigating issues concerning self-controllable, reliable, feasible, and compatible mechanics for autonomous mobile robots. To show how MTP can be applied in the design process we propose a novel methodology, named as Mecha-Telligence Methodology (MTM). Mechanical design by the proposed methodology is based on preference classification of the robot specification described by interaction of the robot with its environment and the physical parameters of the robot mechatronics. After defining new terms, we investigate the feasibility of the proposed methodology to the mechanical design of an autonomous mobile sewer inspection robot. In this industrial project we show how a passive-active intelligent moving mechanism can be designed using the MTM and employed in the field.展开更多
Virtually all conventional optimizations are Performed in a batch computer environment. No graphic information during the optimization process is provided. The research tactics and implementation procedure of interact...Virtually all conventional optimizations are Performed in a batch computer environment. No graphic information during the optimization process is provided. The research tactics and implementation procedure of interactivegraphics in mechanical optimum design are presented. An interactive Graphics Mechanical Optimum Design Program(IGMODP) for microcomputers is developed. The example of wheeled loader' s working device optimum design usingIGMODP is carried out.展开更多
Long-term, body-adhered medical devices rely on an adhesive interface to maintain contact with the patient. The greatest threat to on-body adhesion is mechanical stress imparted on the medical device. Several factors ...Long-term, body-adhered medical devices rely on an adhesive interface to maintain contact with the patient. The greatest threat to on-body adhesion is mechanical stress imparted on the medical device. Several factors contribute to the ability of the device to withstand such stresses, such as the mechanical design, shape, and size of the device. This analysis investigates the impact that design changes to the device have on the stress and strain experienced by the system when acted on by a stressor. The analysis also identifies the design changes that are most effective at reducing the stress and strain. An explicit dynamic finite element analysis method was used to simulate several design iterations and a regression analysis was performed to quantify the relationship between design and resultant stress and strain. The shape, height, size, and taper of the medical device were modified, and the results indicate that, to reduce stress and strain in the system, the device should resemble a square in shape, be short in height, and small in size with a large taper. The square shape experienced 17.5% less stress compared to the next best performing shape. A 10% reduction in device height resulted in a 21% reduction in stress and 24% reduction in strain. A 20% reduction in device size caused a 7% reduction in stress and 2% reduction in strain. A 20% increase in device taper size led to a negligible reduction in stress and a 6% reduction in strain. The height of the device had the greatest impact on the resultant stress and strain.展开更多
A design project was used in junior level mechanical design course to challenge the students' creativity skills. Beside the theoretical foundation of the course subject, the students were introduced to several profes...A design project was used in junior level mechanical design course to challenge the students' creativity skills. Beside the theoretical foundation of the course subject, the students were introduced to several professional skills such as: decision making tools, technical review meetings, interaction with customers, and teamwork skills. The design challenge was to develop a bike rack to meet a list of technical and marketing constraints. Details of the project requirements are presented with a brief overview of the main project mentoring tools. Students' creativity is discussed through two samples of the student work. It was noticed that, the basic creativity skills of the students can be improved by using some of the training tools, however, the students vary in their response to this training.展开更多
The technique of cutting slabstone with stone-sawi ng machine is analyzed completely. A new kind of cutting movement trajectory is gi ven whose actual cutting efficiency is near to 100%. It can reduce the energy w ear...The technique of cutting slabstone with stone-sawi ng machine is analyzed completely. A new kind of cutting movement trajectory is gi ven whose actual cutting efficiency is near to 100%. It can reduce the energy w earing greatly, and the surface quality of the product is improved to the utmost extent. The design mechanism of the optimal cutting movement trajectory system structure is analyzed incisively. At the same time, the principle of the complex movement of horizontal movement and swing is researched. The optimal design scheme of th e cutting movement trajectory system structure is set up. The choice method to g et the superior value of the movement system structure is found. The mathematics function formula is established which exhibits the relationship between the par ameter of the complex movement structure and that of the system movement structu re. By the formula, the precision value of the offset can be figured out. The r ule is adapted to different types of energy-saving stone-sawing machines. The complex movement structure of horizontal movement and swing is designed to f ulfill the cutting movement. It can make the saw frame move up with the hanging pod deviating from the vertical direction. At the same time, the saw frame have a down-movement. Then the sum of the two movements is near to zero, and the saw blade and the stone can keep in touch during the whole horizontal cutting. The result is that the actual cutting efficiency is 100%. Also, when the hanging pod moves to the limited position, the saw frame can keep the original inertia, and continue to swing up. It makes the back-cutting have high energy-storing. The optimal design of the eccentricity balance wheel is done. The mathematics fo rmula for expressing the movement system structure is deduced. The calculation m ethod and formula is set up which is used to get the value of important componen ts such as offset. The choice method and formula of elasticity distortion coeffi cient is set up when the saw frame moves smoothly. It is concluded that the offs et is the key dimension to actualize the optimal cutting movement trajectory. The resolving of the technical problems discussed above offers a theoretic and technical basis for optimal design of energy-saving stone-sawing machines.展开更多
Amid the growing interest in triboelectric nanogenerators(TENGs)as novel energy-harvesting devices,several studies have focused on direct current(DC)TENGs to generate a stable DC output for operating electronic device...Amid the growing interest in triboelectric nanogenerators(TENGs)as novel energy-harvesting devices,several studies have focused on direct current(DC)TENGs to generate a stable DC output for operating electronic devices.However,owing to the working mechanisms of conventional DC TENGs,generating a stable DC output from reciprocating motion remains a challenge.Accordingly,we propose a bidirectional rotating DC TENG(BiR-TENG),which can generate DC outputs,regardless of the direction of rotation,from reciprocating motions.The distinct design of the BiR-TENG enables the mechanical rectification of the alternating current output into a rotational-direction-dependent DC output.Furthermore,it allows the conversion of the rotational-direction-dependent DC output into a unidirectional DC output by adapting the configurations depending on the rotational direction.Owing to these tailored design strategies and subsequent optimizations,the BiR-TENG could generate an effective unidirectional DC output.Applications of the BiR-TENG for the reciprocating motions of swinging doors and waves were demonstrated by harnessing this output.This study demonstrates the potential of the BiR-TENG design strategy as an effective and versatile solution for energy harvesting from reciprocating motions,highlighting the suitability of DC outputs as an energy source for electronic devices.展开更多
By means of Solid Works, three-dimensional model of automated assembly system was established, and kinematic simulation based on Solid Works Motion of assembly process for relay was performed. The simulation results p...By means of Solid Works, three-dimensional model of automated assembly system was established, and kinematic simulation based on Solid Works Motion of assembly process for relay was performed. The simulation results proved the feasibility of mechanical design. Eventually, the productivity was estimated based on simulation analysis. The mechanical design provided a solution with high reference value to practical design of automated assembly system for relay.展开更多
In view of the shortcomings of traditional teaching in the Mechanical Design Fundamentals course,the teaching resources are integrated,the teaching content,teaching methods,and assessment methods are reformed,scientif...In view of the shortcomings of traditional teaching in the Mechanical Design Fundamentals course,the teaching resources are integrated,the teaching content,teaching methods,and assessment methods are reformed,scientific research results are introduced into course teaching,and the task-driven teaching practice is applied.These measures have improved classroom activity,stimulated independent learning,and laid the foundation for the cultivation of students’engineering literacy and innovative ability.展开更多
Based on a level set model, a topology optimization method has been suggestedrecently. It uses a level set to express the moving structural boundary, which can flexibly handlecomplex topological changes. By combining ...Based on a level set model, a topology optimization method has been suggestedrecently. It uses a level set to express the moving structural boundary, which can flexibly handlecomplex topological changes. By combining vector level set models with gradient projectiontechnology, the level set method for topological optimization is extended to a topologicaloptimization problem with multi-constraints, multi-materials and multi-load cases. Meanwhile, anappropriate nonlinear speed, mapping is established in the tangential space of the activeconstraints for a fast convergence. Then the method is applied to structure designs, mechanism andmaterial designs by a number of benchmark examples. Finally, in order to further improvecomputational efficiency and overcome the difficulty that the level set method cannot generate newmaterial interfaces during the optimization process, the topological derivative analysis isincorporated into the level set method for topological optimization, and a topological derivativeand level set algorithm for topological optimization is proposed.展开更多
Since the knotters on the Chinese rectangular balers are imported from outside of the country, Chinese knotters with independent intellectual property rights is far away from being closed. In order to harvest a large ...Since the knotters on the Chinese rectangular balers are imported from outside of the country, Chinese knotters with independent intellectual property rights is far away from being closed. In order to harvest a large quantity of straw in a short period on the small-scale lands of China, basic requirements on the knotters are summarized. Mathematical model of the knotter is also determined uniquely. Furthermore, the ^-type-knots knotter equipped on the Chinese square baler to form the ~ type knots is designed. Knotting rate experiments of the qb-type-knots knotter on the test bench and in the wheat/maize straws covered fields are carried out to check the knotting performances of the knotter. The parameters of the formed knots are also tested. The experiments results show that the knotting rate of the qb-type-knots knotter reaches 100.0% on the test bench without straws, while reaches 99.6% in the wheat straws covered field and 100.0% in the maize straws covered field. The average maximum force in the knotting process is 194.7 N in the lab experiment. The length out of the knots formed in lab is 15.9%-20.6% lower than the knots formed in the field experiment. The breaking force of the knots formed in the field is 115.9%-167.2% higher than the knots formed in lab due to the higher preload and interactions with the compacted bales. Highly relevant relationships exist between the breaking force of the formed knots and the maximum force in the forming process of the knots in the lab experiment. The designed knotter breaks out the embarrassing situation of the domestic knotters which don't have independent intellectual property rights, and promotes the development of Chinese knotter technology, and the mathematical model is helpful for designing new type of knotters.展开更多
A new spherical mobile robot BHQ-1 is designed. The spherical robot is driven by two internally mounted motors that induce the ball to move straight and turn around on a fiat surface. A dynamic model of the robot is d...A new spherical mobile robot BHQ-1 is designed. The spherical robot is driven by two internally mounted motors that induce the ball to move straight and turn around on a fiat surface. A dynamic model of the robot is developed with Lagrange method and factors affecting the driving torque of two motors are analyzed. The relationship between the turning radius of the robot and the length of two links is discussed in order to optimize its mechanism design. Simulation and experimental results demonstrate the good controllability and motion performance of BHQ-1.展开更多
As for the complex operational tasks in the unstructured environment with narrow workspace and numerous obstacles,the traditional robots cannot accomplish these mentioned complex operational tasks and meet the dexteri...As for the complex operational tasks in the unstructured environment with narrow workspace and numerous obstacles,the traditional robots cannot accomplish these mentioned complex operational tasks and meet the dexterity demands.The hyper-redundant bionic robots can complete complex tasks in the unstructured environments by simulating the motion characteristics of the elephant’s trunk and octopus tentacles.Compared with traditional robots,the hyper-redundant bionic robots can accomplish complex tasks because of their flexible structure.A hyper-redundant elephant’s trunk robot(HRETR)with an open structure is developed in this paper.The content includes mechanical structure design,kinematic analysis,virtual prototype simulation,control system design,and prototype building.This design is inspired by the flexible motion of an elephant’s trunk,which is expansible and is composed of six unit modules,namely,3UPS-PS parallel in series.First,the mechanical design of the HRETR is completed according to the motion characteristics of an elephant’s trunk and based on the principle of mechanical bionic design.After that,the backbone mode method is used to establish the kinematic model of the robot.The simulation software SolidWorks and ADAMS are combined to analyze the kinematic characteristics when the trajectory of the end moving platform of the robot is assigned.With the help of ANSYS,the static stiffness of each component and the whole robot is analyzed.On this basis,the materials of the weak parts of the mechanical structure and the hardware are selected reasonably.Next,the extensible structures of software and hardware control system are constructed according to the modular and hierarchical design criteria.Finally,the prototype is built and its performance is tested.The proposed research provides a method for the design and development for the hyper-redundant bionic robot.展开更多
Large quadruped mammals,such as ruminants,have outstanding motion ability,including running and bounding.These advanced motion abilities are related to the buffer effect of their complicated musculoskeletal systems.Ho...Large quadruped mammals,such as ruminants,have outstanding motion ability,including running and bounding.These advanced motion abilities are related to the buffer effect of their complicated musculoskeletal systems.However,the buffer effect of most bio-robots is not satisfactory owing to the simple design of their buffer systems.In this paper,a physiological analysis of the ruminant musculoskeletal system is presented to explain the intrinsic buffer mechanism of motion.Based on the physical buffer parts of the ruminant limbs,the corresponding bionic mappings were determined.These mappings were used to guide the mechanism design of the robot multistage buffer system.The multistage buffer system includes two main buffer mechanisms:the first stage and the second stage.The buffer mechanism analysis of the first stage and multiple stages is discussed in theory to compare the effects between the normal single buffer system and the novel multistage buffer system.Then,the detailed mechanical structure of the limbs was designed based on the limb mechanism design.To further verify the superior efficacy of the multistage buffer system,the corresponding walking simulation experiments were conducted after the virtual prototype of a quadruped robot with a novel limb was built completely.Both theoretical analysis and simulation experiments prove that the bionic robot design with the novel multistage buffer system achieves better motion performance than the traditional robot buffer design and can be regarded as the design template of the robot limb.展开更多
文摘Intelligent optimization algorithm belongs to a kind of emerging technology,show good characteristics,such as high performance,applicability,its algorithm includes many contents,including genetic,particle swarm and artificial neural network algorithm,compared with the traditional optimization way,these algorithms can be applied to a variety of situations,meet the demand of solution,in the mechanical design industry has wide application prospects.This paper analyzes the application of the algorithm in mechanical design and the comparison of the results to verify the significance of the intelligent optimization algorithm in mechanical design.
基金supported by National Natural Science Foundation of China (Grant No. 50875161, No. 50405017)National Hi-Tech Research and Development Program of China (863 Program, Grant No. 2006AA04Z118)
文摘A servo press is a new type of mechanical press that is driven by programmable motors and offers superior performance such as low noise, excellent efficiency and high precision for metal forming operations. Similar to multi-link mechanical presses, a servo mechanical press tends to grow in size as the tonnage increases that calls for larger, heavy duty servo motors, which could be expensive and may not even be available. In this paper, a new concept of servo mechanical press with redundant actuation is proposed firstly using two servo motors driving one input shaft, i.e. one-point-two-motor mode that makes it possible to produce a larger press with available servomotors. Then the punching mechanism design is detailed. The performance indices are set up including mechanical advantage reciprocal and link force ratios. A bounded feasible solution space is constructed for dimensional synthesis based on non-dimensional link lengths and assembly conditions. The performance atlases are depicted over the bounded feasible solution space that lead to a visual solution of the punching mechanism with global optimization. Finally, case studies are given to illustrate the design method with visual global optimization, and a prototype with 200 t punching force is being developed in our laboratory to demonstrate efficacy of the new concept for servo mechanical press. The presented research provides a feasible solution to the development of heavy-duty servo mechanical presses and finds potential applications in the development of other types of heavy equipments with electric drive.
基金Projects(61463009,11264005,11361014)supported by the National Natural Science Foundation of ChinaProject([2013]2082)supported by the Science Technology Foundation of Guizhou Province,China
文摘A novel hybrid algorithm named ABC-BBO, which integrates artificial bee colony(ABC) algorithm with biogeography-based optimization(BBO) algorithm, is proposed to solve constrained mechanical design problems. ABC-BBO combined the exploration of ABC algorithm with the exploitation of BBO algorithm effectively, and hence it can generate the promising candidate individuals. The proposed hybrid algorithm speeds up the convergence and improves the algorithm's performance. Several benchmark test functions and mechanical design problems are applied to verifying the effects of these improvements and it is demonstrated that the performance of this proposed ABC-BBO is superior to or at least highly competitive with other population-based optimization approaches.
基金Sponsored by the National Natural Science Foudation of China(50905016)
文摘A kind of automatic shift schedule optimization method is provided for a tracked vehicle with hydrodynamic-mechanical transmission in order to improve its dynamic performance. A dynamic model of integrated hydrodynamic-mechanical transmission is built in MATLAB/Simdriveline environment, and an optimum shift schedule is derived by using iSight software to call the dynamic model above, then the shift schedule is achieved after optimization. The simulation results show that the method is significant to improve the dynamic performance and gear-shifting smoothness theoretically and practically.
文摘Erratum to:International Journal of Minerals, Metallurgy and Materials Volume 26, Number 9, September 2019, Page 1151https://doi.org/10.1007/s12613-019-1854-1The original version of this article unfortunately contained a mistake. The presentation of Fig. 11 was incorrect. The correct version is given below:
文摘In this paper, a Web-based Mechanical Design and A na lysis Framework (WMDAF) is proposed. This WMADF allows designers to develop web -based computer aided programs in a systematic way during the collaborative mec hanical system design and analysis process. This system is based on an emerg ing web-based Content Management System (CMS) called eXtended Object Oriented P ortal System (XOOPS). Due to the Open Source Status of the XOOPS CMS, programs d eveloped with this framework can be further customized to satisfy the demands of the user. To introduce the use of this framework, this paper exams three differ ent types of mechanical design and analysis problems. First, a repetitive design consideration and calculation process is transferred into WMADF programs to gai n efficiency for wired collaborative team. Second, the considered product solid model is created directly through the use of XOOPS program and Microsoft Compone nt Object Model (COM) instances. To the end of the paper, an example linked with ANSYS is used to indicate the possible application of this framework.
文摘The concept of Intelligent Mechanical Design (IMD) is presented to show how a mechanical structure can be designed to affect robot controllability, simplification and task performance. Exploring this concept produces landmarks in the territory of mechanical robot design in the form of seven design principles. The design principles, which we call the Mecha-Telligence Principles (MTP), provide guidance on how to design mechanics for autonomous mobile robots. These principles guide us to ask the right questions when investigating issues concerning self-controllable, reliable, feasible, and compatible mechanics for autonomous mobile robots. To show how MTP can be applied in the design process we propose a novel methodology, named as Mecha-Telligence Methodology (MTM). Mechanical design by the proposed methodology is based on preference classification of the robot specification described by interaction of the robot with its environment and the physical parameters of the robot mechatronics. After defining new terms, we investigate the feasibility of the proposed methodology to the mechanical design of an autonomous mobile sewer inspection robot. In this industrial project we show how a passive-active intelligent moving mechanism can be designed using the MTM and employed in the field.
文摘Virtually all conventional optimizations are Performed in a batch computer environment. No graphic information during the optimization process is provided. The research tactics and implementation procedure of interactivegraphics in mechanical optimum design are presented. An interactive Graphics Mechanical Optimum Design Program(IGMODP) for microcomputers is developed. The example of wheeled loader' s working device optimum design usingIGMODP is carried out.
文摘Long-term, body-adhered medical devices rely on an adhesive interface to maintain contact with the patient. The greatest threat to on-body adhesion is mechanical stress imparted on the medical device. Several factors contribute to the ability of the device to withstand such stresses, such as the mechanical design, shape, and size of the device. This analysis investigates the impact that design changes to the device have on the stress and strain experienced by the system when acted on by a stressor. The analysis also identifies the design changes that are most effective at reducing the stress and strain. An explicit dynamic finite element analysis method was used to simulate several design iterations and a regression analysis was performed to quantify the relationship between design and resultant stress and strain. The shape, height, size, and taper of the medical device were modified, and the results indicate that, to reduce stress and strain in the system, the device should resemble a square in shape, be short in height, and small in size with a large taper. The square shape experienced 17.5% less stress compared to the next best performing shape. A 10% reduction in device height resulted in a 21% reduction in stress and 24% reduction in strain. A 20% reduction in device size caused a 7% reduction in stress and 2% reduction in strain. A 20% increase in device taper size led to a negligible reduction in stress and a 6% reduction in strain. The height of the device had the greatest impact on the resultant stress and strain.
文摘A design project was used in junior level mechanical design course to challenge the students' creativity skills. Beside the theoretical foundation of the course subject, the students were introduced to several professional skills such as: decision making tools, technical review meetings, interaction with customers, and teamwork skills. The design challenge was to develop a bike rack to meet a list of technical and marketing constraints. Details of the project requirements are presented with a brief overview of the main project mentoring tools. Students' creativity is discussed through two samples of the student work. It was noticed that, the basic creativity skills of the students can be improved by using some of the training tools, however, the students vary in their response to this training.
文摘The technique of cutting slabstone with stone-sawi ng machine is analyzed completely. A new kind of cutting movement trajectory is gi ven whose actual cutting efficiency is near to 100%. It can reduce the energy w earing greatly, and the surface quality of the product is improved to the utmost extent. The design mechanism of the optimal cutting movement trajectory system structure is analyzed incisively. At the same time, the principle of the complex movement of horizontal movement and swing is researched. The optimal design scheme of th e cutting movement trajectory system structure is set up. The choice method to g et the superior value of the movement system structure is found. The mathematics function formula is established which exhibits the relationship between the par ameter of the complex movement structure and that of the system movement structu re. By the formula, the precision value of the offset can be figured out. The r ule is adapted to different types of energy-saving stone-sawing machines. The complex movement structure of horizontal movement and swing is designed to f ulfill the cutting movement. It can make the saw frame move up with the hanging pod deviating from the vertical direction. At the same time, the saw frame have a down-movement. Then the sum of the two movements is near to zero, and the saw blade and the stone can keep in touch during the whole horizontal cutting. The result is that the actual cutting efficiency is 100%. Also, when the hanging pod moves to the limited position, the saw frame can keep the original inertia, and continue to swing up. It makes the back-cutting have high energy-storing. The optimal design of the eccentricity balance wheel is done. The mathematics fo rmula for expressing the movement system structure is deduced. The calculation m ethod and formula is set up which is used to get the value of important componen ts such as offset. The choice method and formula of elasticity distortion coeffi cient is set up when the saw frame moves smoothly. It is concluded that the offs et is the key dimension to actualize the optimal cutting movement trajectory. The resolving of the technical problems discussed above offers a theoretic and technical basis for optimal design of energy-saving stone-sawing machines.
基金This work was supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.2022R1C1C1008831).This work was also supported by the Human Resources Development of the Korea Institute of Energy Technology Evaluation and Planning(KETEP)grant funded by the Ministry of Trade,Industry and Energy of Korea(No.RS-2023-00244330).S J P was supported by Basic Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(No.2018R1A6A1A03025526).
文摘Amid the growing interest in triboelectric nanogenerators(TENGs)as novel energy-harvesting devices,several studies have focused on direct current(DC)TENGs to generate a stable DC output for operating electronic devices.However,owing to the working mechanisms of conventional DC TENGs,generating a stable DC output from reciprocating motion remains a challenge.Accordingly,we propose a bidirectional rotating DC TENG(BiR-TENG),which can generate DC outputs,regardless of the direction of rotation,from reciprocating motions.The distinct design of the BiR-TENG enables the mechanical rectification of the alternating current output into a rotational-direction-dependent DC output.Furthermore,it allows the conversion of the rotational-direction-dependent DC output into a unidirectional DC output by adapting the configurations depending on the rotational direction.Owing to these tailored design strategies and subsequent optimizations,the BiR-TENG could generate an effective unidirectional DC output.Applications of the BiR-TENG for the reciprocating motions of swinging doors and waves were demonstrated by harnessing this output.This study demonstrates the potential of the BiR-TENG design strategy as an effective and versatile solution for energy harvesting from reciprocating motions,highlighting the suitability of DC outputs as an energy source for electronic devices.
文摘By means of Solid Works, three-dimensional model of automated assembly system was established, and kinematic simulation based on Solid Works Motion of assembly process for relay was performed. The simulation results proved the feasibility of mechanical design. Eventually, the productivity was estimated based on simulation analysis. The mechanical design provided a solution with high reference value to practical design of automated assembly system for relay.
基金The Education and Teaching Research Project of National University of Defense Technology(Project Number:U2020103)。
文摘In view of the shortcomings of traditional teaching in the Mechanical Design Fundamentals course,the teaching resources are integrated,the teaching content,teaching methods,and assessment methods are reformed,scientific research results are introduced into course teaching,and the task-driven teaching practice is applied.These measures have improved classroom activity,stimulated independent learning,and laid the foundation for the cultivation of students’engineering literacy and innovative ability.
基金This project is supported by National Natural Science Foundation of China(No.598005001, No.10332010) and Key Science and Technology Research Project of Ministry of Education (No.104060).
文摘Based on a level set model, a topology optimization method has been suggestedrecently. It uses a level set to express the moving structural boundary, which can flexibly handlecomplex topological changes. By combining vector level set models with gradient projectiontechnology, the level set method for topological optimization is extended to a topologicaloptimization problem with multi-constraints, multi-materials and multi-load cases. Meanwhile, anappropriate nonlinear speed, mapping is established in the tangential space of the activeconstraints for a fast convergence. Then the method is applied to structure designs, mechanism andmaterial designs by a number of benchmark examples. Finally, in order to further improvecomputational efficiency and overcome the difficulty that the level set method cannot generate newmaterial interfaces during the optimization process, the topological derivative analysis isincorporated into the level set method for topological optimization, and a topological derivativeand level set algorithm for topological optimization is proposed.
基金supported by Program for Changjiang Scholars and Innovative Research Team in University of China(Grant No.IRT13039)National Natural Science Foundation of China(Grant No.51175499)+1 种基金Beijing Municipal Natural Science Foundation of China(Grant No.6112015)Chinese Universities Scientific Fund(Grant No.2012YJ091)
文摘Since the knotters on the Chinese rectangular balers are imported from outside of the country, Chinese knotters with independent intellectual property rights is far away from being closed. In order to harvest a large quantity of straw in a short period on the small-scale lands of China, basic requirements on the knotters are summarized. Mathematical model of the knotter is also determined uniquely. Furthermore, the ^-type-knots knotter equipped on the Chinese square baler to form the ~ type knots is designed. Knotting rate experiments of the qb-type-knots knotter on the test bench and in the wheat/maize straws covered fields are carried out to check the knotting performances of the knotter. The parameters of the formed knots are also tested. The experiments results show that the knotting rate of the qb-type-knots knotter reaches 100.0% on the test bench without straws, while reaches 99.6% in the wheat straws covered field and 100.0% in the maize straws covered field. The average maximum force in the knotting process is 194.7 N in the lab experiment. The length out of the knots formed in lab is 15.9%-20.6% lower than the knots formed in the field experiment. The breaking force of the knots formed in the field is 115.9%-167.2% higher than the knots formed in lab due to the higher preload and interactions with the compacted bales. Highly relevant relationships exist between the breaking force of the formed knots and the maximum force in the forming process of the knots in the lab experiment. The designed knotter breaks out the embarrassing situation of the domestic knotters which don't have independent intellectual property rights, and promotes the development of Chinese knotter technology, and the mathematical model is helpful for designing new type of knotters.
基金This project is supported by National Hi-tech Research and Development Program of China(863 Program, No.2003AA404190).
文摘A new spherical mobile robot BHQ-1 is designed. The spherical robot is driven by two internally mounted motors that induce the ball to move straight and turn around on a fiat surface. A dynamic model of the robot is developed with Lagrange method and factors affecting the driving torque of two motors are analyzed. The relationship between the turning radius of the robot and the length of two links is discussed in order to optimize its mechanism design. Simulation and experimental results demonstrate the good controllability and motion performance of BHQ-1.
基金Supported by National Natural Science Foundation of China(Grant No.51375288)Science and Technology Program of Guangdong Province of China(Grant No.2020ST004)+1 种基金Department of Education of Guangdong Province of China(Grant No.2017KZDXM036and Special Project for Science and Technology Innovation Team of Foshan City of China(Grant No.2018IT100052).
文摘As for the complex operational tasks in the unstructured environment with narrow workspace and numerous obstacles,the traditional robots cannot accomplish these mentioned complex operational tasks and meet the dexterity demands.The hyper-redundant bionic robots can complete complex tasks in the unstructured environments by simulating the motion characteristics of the elephant’s trunk and octopus tentacles.Compared with traditional robots,the hyper-redundant bionic robots can accomplish complex tasks because of their flexible structure.A hyper-redundant elephant’s trunk robot(HRETR)with an open structure is developed in this paper.The content includes mechanical structure design,kinematic analysis,virtual prototype simulation,control system design,and prototype building.This design is inspired by the flexible motion of an elephant’s trunk,which is expansible and is composed of six unit modules,namely,3UPS-PS parallel in series.First,the mechanical design of the HRETR is completed according to the motion characteristics of an elephant’s trunk and based on the principle of mechanical bionic design.After that,the backbone mode method is used to establish the kinematic model of the robot.The simulation software SolidWorks and ADAMS are combined to analyze the kinematic characteristics when the trajectory of the end moving platform of the robot is assigned.With the help of ANSYS,the static stiffness of each component and the whole robot is analyzed.On this basis,the materials of the weak parts of the mechanical structure and the hardware are selected reasonably.Next,the extensible structures of software and hardware control system are constructed according to the modular and hierarchical design criteria.Finally,the prototype is built and its performance is tested.The proposed research provides a method for the design and development for the hyper-redundant bionic robot.
基金Supported by the National Key Research and Development Program of China(Grant No.2019YFB1309600)the National Natural Science Foundation of China(Grant Nos.51775011&91748201).
文摘Large quadruped mammals,such as ruminants,have outstanding motion ability,including running and bounding.These advanced motion abilities are related to the buffer effect of their complicated musculoskeletal systems.However,the buffer effect of most bio-robots is not satisfactory owing to the simple design of their buffer systems.In this paper,a physiological analysis of the ruminant musculoskeletal system is presented to explain the intrinsic buffer mechanism of motion.Based on the physical buffer parts of the ruminant limbs,the corresponding bionic mappings were determined.These mappings were used to guide the mechanism design of the robot multistage buffer system.The multistage buffer system includes two main buffer mechanisms:the first stage and the second stage.The buffer mechanism analysis of the first stage and multiple stages is discussed in theory to compare the effects between the normal single buffer system and the novel multistage buffer system.Then,the detailed mechanical structure of the limbs was designed based on the limb mechanism design.To further verify the superior efficacy of the multistage buffer system,the corresponding walking simulation experiments were conducted after the virtual prototype of a quadruped robot with a novel limb was built completely.Both theoretical analysis and simulation experiments prove that the bionic robot design with the novel multistage buffer system achieves better motion performance than the traditional robot buffer design and can be regarded as the design template of the robot limb.