对每个单元都引入应变比能系数,通过追求对局部应力约束的高精度逼近,使独立.连续.映射(Independent Continuous and Mapping,ICM)方法中全局化应变比能约束的表达更为可靠,同时采取放松初始应变比能系数的手段加速优化迭代。利用结构最...对每个单元都引入应变比能系数,通过追求对局部应力约束的高精度逼近,使独立.连续.映射(Independent Continuous and Mapping,ICM)方法中全局化应变比能约束的表达更为可靠,同时采取放松初始应变比能系数的手段加速优化迭代。利用结构最大Mises应力对许用应力比值的幂函数对全局化处理后的应变比能约束限进行修正,或者控制结构的最大应力,或者加速优化迭代。为了使拓扑构型向合理方向演变,每次迭代都对拓扑变量履行从连续到离散的反演,反演阈值自动计算。各算例均以较少的结构重分析次数,优化得到了类似理论最优解Michell桁架的拓扑图形,表明本文处理应力约束下结构拓扑优化问题的方法是合理和高效的。展开更多
By analyzing the correlation between modal calculations and modal experiments of a typical supporter, an effective finite element analysis( FEA)model of the actual aerospace supporter is created. According to the anal...By analyzing the correlation between modal calculations and modal experiments of a typical supporter, an effective finite element analysis( FEA)model of the actual aerospace supporter is created. According to the analysis of constrained viscoelastic damping, the strategies of PVC have been worked out, and the correlation between modal calculations and modal experiments of the supporter has also been computed, and then, an experiment has been designed based on the calculation results. The results of experiments verify that the PVC strategy can effectively suppress vibration.展开更多
A theoretical basis of optimally designed BRAQWET is pr esented. The optimum parameters of MgZnSSe/ZnSe BRAQWET are obtained by the ca lculation of band-structure according to the depletion approximation.
Efforts to speed up China's coal bed methane (CBM) exploration developments related to production safety, optimization of energy structures, prevention of energy waste and reduction of greenhouse gas emissions are...Efforts to speed up China's coal bed methane (CBM) exploration developments related to production safety, optimization of energy structures, prevention of energy waste and reduction of greenhouse gas emissions are all of great significance. In order to strengthen CBM exploration and development in China and to encourage increased growth in the CBM industry, we firstly give a general overview of the recent technological innovations and other developments in CBM exploration in the U.S., Canada and other countries. Using this background information as the starting point, we further present observations and analyses of CBM exploration and development, preferential policies, technical support and implications of R&D for CBM development in China. The results show that the problems related to CBM exploration technology development and lack of a complete set of management policies are still the major issues slowing down the growth of domestic CBM industry. Development of resource exploration and technology, R&D and establishment of favorable government policy to support the industry and the creation of a relevant information platform, etc. are finally recommended.展开更多
文摘对每个单元都引入应变比能系数,通过追求对局部应力约束的高精度逼近,使独立.连续.映射(Independent Continuous and Mapping,ICM)方法中全局化应变比能约束的表达更为可靠,同时采取放松初始应变比能系数的手段加速优化迭代。利用结构最大Mises应力对许用应力比值的幂函数对全局化处理后的应变比能约束限进行修正,或者控制结构的最大应力,或者加速优化迭代。为了使拓扑构型向合理方向演变,每次迭代都对拓扑变量履行从连续到离散的反演,反演阈值自动计算。各算例均以较少的结构重分析次数,优化得到了类似理论最优解Michell桁架的拓扑图形,表明本文处理应力约束下结构拓扑优化问题的方法是合理和高效的。
基金Sponsored by the National 863 Project of China (Grant No. 863 -2 -416)
文摘By analyzing the correlation between modal calculations and modal experiments of a typical supporter, an effective finite element analysis( FEA)model of the actual aerospace supporter is created. According to the analysis of constrained viscoelastic damping, the strategies of PVC have been worked out, and the correlation between modal calculations and modal experiments of the supporter has also been computed, and then, an experiment has been designed based on the calculation results. The results of experiments verify that the PVC strategy can effectively suppress vibration.
文摘A theoretical basis of optimally designed BRAQWET is pr esented. The optimum parameters of MgZnSSe/ZnSe BRAQWET are obtained by the ca lculation of band-structure according to the depletion approximation.
基金the continuous supply of funds to the National Science and Technology Major Project-Developing Great Oil & Gas Field and Coal Bed Gas (No. 2008ZX05)
文摘Efforts to speed up China's coal bed methane (CBM) exploration developments related to production safety, optimization of energy structures, prevention of energy waste and reduction of greenhouse gas emissions are all of great significance. In order to strengthen CBM exploration and development in China and to encourage increased growth in the CBM industry, we firstly give a general overview of the recent technological innovations and other developments in CBM exploration in the U.S., Canada and other countries. Using this background information as the starting point, we further present observations and analyses of CBM exploration and development, preferential policies, technical support and implications of R&D for CBM development in China. The results show that the problems related to CBM exploration technology development and lack of a complete set of management policies are still the major issues slowing down the growth of domestic CBM industry. Development of resource exploration and technology, R&D and establishment of favorable government policy to support the industry and the creation of a relevant information platform, etc. are finally recommended.
