Domes are popularly used for column free areas. They are employed as covers to reservoirs and treatment units and also as containment in nuclear reactors. Inverted domes are popular as foundations. Structures are buil...Domes are popularly used for column free areas. They are employed as covers to reservoirs and treatment units and also as containment in nuclear reactors. Inverted domes are popular as foundations. Structures are built with an intended end use for a specified utility period. The functional requirement is to serve the purpose and the structural requirement constitutes stability, strength, safety, serviceability and durability. Satisfaction of these requirements at affordable costs is the goal of structural optimization. This paper demonstrates the need and scope for optimization of domes by formulating and solving the problem by use of calculus （volume of material is the objective function being minimized using first principles of calculus）. A simple but elegant method is suggested for determination of wind stresses by statics which compares very well with that obtained by rigorous method.展开更多
In order to improve the strength and stiffness of shield cutterhead, the method of fuzzy mathematics theory in combination with the finite element analysis is adopted. An optimal design model of structural parameters ...In order to improve the strength and stiffness of shield cutterhead, the method of fuzzy mathematics theory in combination with the finite element analysis is adopted. An optimal design model of structural parameters for shield cutterhead is formulated,based on the complex engineering technical requirements. In the model, as the objective function of the model is a composite function of the strength and stiffness, the response surface method is applied to formulate the approximate function of objective function in order to reduce the solution scale of optimal problem. A multi-objective genetic algorithm is used to solve the cutterhead structure design problem and the change rule of the stress-strain with various structural parameters as well as their optimal values were researched under specific geological conditions. The results show that compared with original cutterhead structure scheme, the obtained optimal scheme of the cutterhead structure can greatly improve the strength and stiffness of the cutterhead, which can be seen from the reduction of its maximum equivalent stress by 21.2%, that of its maximum deformation by 0.75%, and that of its mass by 1.04%.展开更多
The endochronic equations proposed by Valanis (1980) were extended to a finite deformation range. Jaumanns rate, Fus rate and Wus rate were incorporated into the endochronic equations to analyze simple shear finite de...The endochronic equations proposed by Valanis (1980) were extended to a finite deformation range. Jaumanns rate, Fus rate and Wus rate were incorporated into the endochronic equations to analyze simple shear finite deformation. Incremental equations and numerical solutions are deduced for three endochronic objective models. The results show that an oscillatory shear stress response to a monotonically increasing shear strain occurs when the Jaumanns rate objective model is employed for endochronic materials. The oscillatory response is dependent on the adopted objective rate. Compared with the Jaumanns rate, the Fus rate and the Wus rate satisfy the restrictions to elastic-plastic constitutive relations and are in agreement with the experimental results.展开更多
In this paper, we conduct research on the challenges and the countermeasures of Chinese language and literature education underteaching reform background. Chinese literature professional training objectives, it is for...In this paper, we conduct research on the challenges and the countermeasures of Chinese language and literature education underteaching reform background. Chinese literature professional training objectives, it is for the country to create high literary accomplishment of thestudents. Make students in carrying forward the Chinese culture at the same time, to fi nd beauty, appreciate beauty and create beauty, and improvetheir personality and taste. Society for Chinese language and literature talent is looking forward to more and more high, therefore, the Chineselanguage and the literature professional teachers need to focus on the employment situation, based on fundamental professional knowledge,strengthen students on the basis of this, the application of Chinese language and literature teaching, let the students application ability graduallyimprove, to adapt to the demand in today’s society. Under this basis, this paper proposes the new idea that is innovative.展开更多
文摘Domes are popularly used for column free areas. They are employed as covers to reservoirs and treatment units and also as containment in nuclear reactors. Inverted domes are popular as foundations. Structures are built with an intended end use for a specified utility period. The functional requirement is to serve the purpose and the structural requirement constitutes stability, strength, safety, serviceability and durability. Satisfaction of these requirements at affordable costs is the goal of structural optimization. This paper demonstrates the need and scope for optimization of domes by formulating and solving the problem by use of calculus （volume of material is the objective function being minimized using first principles of calculus）. A simple but elegant method is suggested for determination of wind stresses by statics which compares very well with that obtained by rigorous method.
基金Project(51074180) supported by the National Natural Science Foundation of ChinaProject(2012AA041801) supported by the National High Technology Research and Development Program of China+2 种基金Project(2007CB714002) supported by the National Basic Research Program of ChinaProject(2013GK3003) supported by the Technology Support Plan of Hunan Province,ChinaProject(2010FJ1002) supported by Hunan Science and Technology Major Program,China
文摘In order to improve the strength and stiffness of shield cutterhead, the method of fuzzy mathematics theory in combination with the finite element analysis is adopted. An optimal design model of structural parameters for shield cutterhead is formulated,based on the complex engineering technical requirements. In the model, as the objective function of the model is a composite function of the strength and stiffness, the response surface method is applied to formulate the approximate function of objective function in order to reduce the solution scale of optimal problem. A multi-objective genetic algorithm is used to solve the cutterhead structure design problem and the change rule of the stress-strain with various structural parameters as well as their optimal values were researched under specific geological conditions. The results show that compared with original cutterhead structure scheme, the obtained optimal scheme of the cutterhead structure can greatly improve the strength and stiffness of the cutterhead, which can be seen from the reduction of its maximum equivalent stress by 21.2%, that of its maximum deformation by 0.75%, and that of its mass by 1.04%.
文摘The endochronic equations proposed by Valanis (1980) were extended to a finite deformation range. Jaumanns rate, Fus rate and Wus rate were incorporated into the endochronic equations to analyze simple shear finite deformation. Incremental equations and numerical solutions are deduced for three endochronic objective models. The results show that an oscillatory shear stress response to a monotonically increasing shear strain occurs when the Jaumanns rate objective model is employed for endochronic materials. The oscillatory response is dependent on the adopted objective rate. Compared with the Jaumanns rate, the Fus rate and the Wus rate satisfy the restrictions to elastic-plastic constitutive relations and are in agreement with the experimental results.
文摘In this paper, we conduct research on the challenges and the countermeasures of Chinese language and literature education underteaching reform background. Chinese literature professional training objectives, it is for the country to create high literary accomplishment of thestudents. Make students in carrying forward the Chinese culture at the same time, to fi nd beauty, appreciate beauty and create beauty, and improvetheir personality and taste. Society for Chinese language and literature talent is looking forward to more and more high, therefore, the Chineselanguage and the literature professional teachers need to focus on the employment situation, based on fundamental professional knowledge,strengthen students on the basis of this, the application of Chinese language and literature teaching, let the students application ability graduallyimprove, to adapt to the demand in today’s society. Under this basis, this paper proposes the new idea that is innovative.
