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
Firstly data standardization technology and combined classification method have been applied to carry out classification of kinematic behaviors and mechanisms in the mapping field between the kinematic behavior level ...Firstly data standardization technology and combined classification method have been applied to carry out classification of kinematic behaviors and mechanisms in the mapping field between the kinematic behavior level and the mechanism level of conceptual design.The principle of computer coding and storing have been built to give a fast and broad selection of mechanisms that meets the requirements of basic motion characters.Then on the basis of mentioned above,the heuristic matching propagation principle (HMPP) of kinematic behaviors and its true table serves as a guide to perform mechanism types selection.Finally an application is given to indicate its practicability and effectiveness.展开更多
Hydrated Cement Treated Crushed Rock Base (HCTCRB) is widely used as a base course in Western Australian pavements. HCTCRB has been designed and used as a basis for empirical approaches and in empirical practices. T...Hydrated Cement Treated Crushed Rock Base (HCTCRB) is widely used as a base course in Western Australian pavements. HCTCRB has been designed and used as a basis for empirical approaches and in empirical practices. These methods are not all-encompassing enough to adequately explain the behaviour of HCTCRB in the field. Recent developments in mechanistic approaches have proven more reliable in the design and analysis of pavement, making it possible to more effectively document the characteristics of HCTCRB. The aim of this study was to carry out laboratory testing to assess the mechanical characteristics of HCTCRB. Conventional triaxial tests and repeated load triaxial tests (RLT tests) were performed. Factors affecting the performance of HCTCRB, namely hydration periods and the amount of added water were also investigated. It was found that the shear strength parameters of HCTCRB were 177 kPa for cohesion (c) and 42~ for the internal friction angle (~). The hydration period, and the water added in this investigation affected the performance of HCTCRB. However, the related trends associated with such factors could not be assessed. All HCTCRB samples showed stress-dependency behaviour. Based on the stress stages of this experiment, the resilient modulus values of HCTCRB ranged from 300 MPa to 1100 MPa. CIRCLY, a computer program based on the multi-layer elastic theory was used in the mechanistic approach to pavement design and analysis, to determine the performance of a typical pavement model using HCTCRB as a base course layer. The mechanistic pavement design parameters for HCTCRB as a base course material were then introduced. The analysis suggests that the suitable depth for HCTCRB as a base layer for WA roads is at least 185 mm for the design equivalent standard axle (ESA) of 10 million.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
In this paper, the problem of reliability-based optimal design of simple offshore platform is studied, and a nonlinear fatigue damage model based on damage mechanics and genetic algorithms are used in the fatigue reli...In this paper, the problem of reliability-based optimal design of simple offshore platform is studied, and a nonlinear fatigue damage model based on damage mechanics and genetic algorithms are used in the fatigue reliability optimum design of the structure under stochastic wave load. The fatigue damage model and the yield failure reliability analyzing model are used in the paper. The reliability of the models and the effectiveness of genetic algorithm are shown by the results of optimum design.展开更多
With demands for applied talents dramatically increasing motivated by economic transformation and China's "Going Out " Strategy, College English reform should deepen ESP teaching, stress application of l...With demands for applied talents dramatically increasing motivated by economic transformation and China's "Going Out " Strategy, College English reform should deepen ESP teaching, stress application of language skills to academic and professionallearning, and serve for students' future development. Therefore, it is vital to explore school-based course design in ESP based onneeds analysis.展开更多
The development of new products of high quality, low unit cost, and short lead time to market are the key elements required for any enterprise to obtain a competitive advantage. For shorting the lead time to market an...The development of new products of high quality, low unit cost, and short lead time to market are the key elements required for any enterprise to obtain a competitive advantage. For shorting the lead time to market and improving the creativity and performances of the product, a rule-based conceptual design approach and a methodology to simulate the conceptual design results generated in conceptual design process in automatical virtual entity form are presented in this paper. This part of paper presents a rule-based conceptual design method for generating creative conceptual design schemes of mechanisms based on Yan's kinematic chain regeneration creative design method. The design rules are adopted to describe the design requirements of the functional characteristics, the connection relationships and topological characteristics among mechanisms. Through the graphs-based reasoning process, the conceptual design space is expanded extremely, and the potential creative conceptual design results are then dug out. By refining the design rules, the solution exploration problem is avioded, and the tendentious conceptual design schemes are generated. Since mechanical, electrical and hydraulic subsystems can be transformed into general mechansims, the conceptual design method presented in this paper can also be applied in the conceptual design problem of complex mechatronic systems. And then the method to identify conceptual design schemes is given.展开更多
Biofilm-forming microorganisms are ubiquitous, but continuous cultivation of these microorganisms with predictable biofilm growth and structural properties remains challenging. The development of a reliable simulated ...Biofilm-forming microorganisms are ubiquitous, but continuous cultivation of these microorganisms with predictable biofilm growth and structural properties remains challenging. The development of a reliable simulated biofilm has been limited by a lack of information about the microorganism subpopulations and fluid-structure interactions involved in biofilm formation and detachment due to mechanical stress. This paper presents a gellan-based hydrogel as an alternative material for a simulated physicochemical biofilm. The mechanical properties of the hydrogel in terms of the storage (G') and loss (G'') moduli can be tuned and adapted to imitate biofilms of different strengths by changing the concentration of gellan and mono(Na+) or divalent (Mg2+) ions. The storage modulus of the hydrogel ranges from 2 to 20 kPa, and the loss modulus ranges from 0.1 to 2.0 kPa. The material constants of the hydrogels and biofilms of Pseudomonas putida KT2440 were experimentally determined by rheometric analysis. A simplified biofilm imitate based on highly hydrolyzed gellan hydrogels was established by using experimental design techniques that permitted independent analyses regardless of growth. This model system design was compared to real biofilms and was adapted to mimic the mechanical properties of biofilms by changing the hydrogel composition, resulting in biofilm-like viscoelastic behavior. The use of a gellan-based hydrogel enables the imitation of biofilm behavior in the absence of growth effects, thus simplifying the system. Biofilm characterization tools can be tested and verified before their application to the measurement of slow-growing, highly variable biofilms to estimate system errors, which are often smaller than the biological variations. In general, this method permits faster and more reliable testing of biofilm mechanical properties.展开更多
Aiming to solve the existing problems with the Quality Course,an EFL online course is developed with an Open Source Course Management System(CMS).The principles and strategies of designing and constructing the course ...Aiming to solve the existing problems with the Quality Course,an EFL online course is developed with an Open Source Course Management System(CMS).The principles and strategies of designing and constructing the course are discussed.The process of developing vocational college students'professional and social competence in the web-based environment is ex plored.Research results show the students are satisfied with the web-based EFL course and the teaching.展开更多
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Sponsored by the Chinese National Foundation of Science Na 59875058.
文摘Firstly data standardization technology and combined classification method have been applied to carry out classification of kinematic behaviors and mechanisms in the mapping field between the kinematic behavior level and the mechanism level of conceptual design.The principle of computer coding and storing have been built to give a fast and broad selection of mechanisms that meets the requirements of basic motion characters.Then on the basis of mentioned above,the heuristic matching propagation principle (HMPP) of kinematic behaviors and its true table serves as a guide to perform mechanism types selection.Finally an application is given to indicate its practicability and effectiveness.
文摘Hydrated Cement Treated Crushed Rock Base (HCTCRB) is widely used as a base course in Western Australian pavements. HCTCRB has been designed and used as a basis for empirical approaches and in empirical practices. These methods are not all-encompassing enough to adequately explain the behaviour of HCTCRB in the field. Recent developments in mechanistic approaches have proven more reliable in the design and analysis of pavement, making it possible to more effectively document the characteristics of HCTCRB. The aim of this study was to carry out laboratory testing to assess the mechanical characteristics of HCTCRB. Conventional triaxial tests and repeated load triaxial tests (RLT tests) were performed. Factors affecting the performance of HCTCRB, namely hydration periods and the amount of added water were also investigated. It was found that the shear strength parameters of HCTCRB were 177 kPa for cohesion (c) and 42~ for the internal friction angle (~). The hydration period, and the water added in this investigation affected the performance of HCTCRB. However, the related trends associated with such factors could not be assessed. All HCTCRB samples showed stress-dependency behaviour. Based on the stress stages of this experiment, the resilient modulus values of HCTCRB ranged from 300 MPa to 1100 MPa. CIRCLY, a computer program based on the multi-layer elastic theory was used in the mechanistic approach to pavement design and analysis, to determine the performance of a typical pavement model using HCTCRB as a base course layer. The mechanistic pavement design parameters for HCTCRB as a base course material were then introduced. The analysis suggests that the suitable depth for HCTCRB as a base layer for WA roads is at least 185 mm for the design equivalent standard axle (ESA) of 10 million.
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.
基金This work was financially supported by the National Science Foundation of China
文摘In this paper, the problem of reliability-based optimal design of simple offshore platform is studied, and a nonlinear fatigue damage model based on damage mechanics and genetic algorithms are used in the fatigue reliability optimum design of the structure under stochastic wave load. The fatigue damage model and the yield failure reliability analyzing model are used in the paper. The reliability of the models and the effectiveness of genetic algorithm are shown by the results of optimum design.
文摘With demands for applied talents dramatically increasing motivated by economic transformation and China's "Going Out " Strategy, College English reform should deepen ESP teaching, stress application of language skills to academic and professionallearning, and serve for students' future development. Therefore, it is vital to explore school-based course design in ESP based onneeds analysis.
基金Supported by National Natural Science Foundation of China(Nos.51375496,51205409)
文摘The development of new products of high quality, low unit cost, and short lead time to market are the key elements required for any enterprise to obtain a competitive advantage. For shorting the lead time to market and improving the creativity and performances of the product, a rule-based conceptual design approach and a methodology to simulate the conceptual design results generated in conceptual design process in automatical virtual entity form are presented in this paper. This part of paper presents a rule-based conceptual design method for generating creative conceptual design schemes of mechanisms based on Yan's kinematic chain regeneration creative design method. The design rules are adopted to describe the design requirements of the functional characteristics, the connection relationships and topological characteristics among mechanisms. Through the graphs-based reasoning process, the conceptual design space is expanded extremely, and the potential creative conceptual design results are then dug out. By refining the design rules, the solution exploration problem is avioded, and the tendentious conceptual design schemes are generated. Since mechanical, electrical and hydraulic subsystems can be transformed into general mechansims, the conceptual design method presented in this paper can also be applied in the conceptual design problem of complex mechatronic systems. And then the method to identify conceptual design schemes is given.
文摘Biofilm-forming microorganisms are ubiquitous, but continuous cultivation of these microorganisms with predictable biofilm growth and structural properties remains challenging. The development of a reliable simulated biofilm has been limited by a lack of information about the microorganism subpopulations and fluid-structure interactions involved in biofilm formation and detachment due to mechanical stress. This paper presents a gellan-based hydrogel as an alternative material for a simulated physicochemical biofilm. The mechanical properties of the hydrogel in terms of the storage (G') and loss (G'') moduli can be tuned and adapted to imitate biofilms of different strengths by changing the concentration of gellan and mono(Na+) or divalent (Mg2+) ions. The storage modulus of the hydrogel ranges from 2 to 20 kPa, and the loss modulus ranges from 0.1 to 2.0 kPa. The material constants of the hydrogels and biofilms of Pseudomonas putida KT2440 were experimentally determined by rheometric analysis. A simplified biofilm imitate based on highly hydrolyzed gellan hydrogels was established by using experimental design techniques that permitted independent analyses regardless of growth. This model system design was compared to real biofilms and was adapted to mimic the mechanical properties of biofilms by changing the hydrogel composition, resulting in biofilm-like viscoelastic behavior. The use of a gellan-based hydrogel enables the imitation of biofilm behavior in the absence of growth effects, thus simplifying the system. Biofilm characterization tools can be tested and verified before their application to the measurement of slow-growing, highly variable biofilms to estimate system errors, which are often smaller than the biological variations. In general, this method permits faster and more reliable testing of biofilm mechanical properties.
文摘Aiming to solve the existing problems with the Quality Course,an EFL online course is developed with an Open Source Course Management System(CMS).The principles and strategies of designing and constructing the course are discussed.The process of developing vocational college students'professional and social competence in the web-based environment is ex plored.Research results show the students are satisfied with the web-based EFL course and the teaching.