A set of basic deformation modes for hybrid stress finite elements are directly derived from the element displacement field. Subsequently, by employing the so-called united orthogonal conditions, a new orthogonalizati...A set of basic deformation modes for hybrid stress finite elements are directly derived from the element displacement field. Subsequently, by employing the so-called united orthogonal conditions, a new orthogonalization method is proposed. The result- ing orthogonal basic deformation modes exhibit simple and clear physical meanings. In addition, they do not involve any material parameters, and thus can be efficiently used to examine the element performance and serve as a unified tool to assess different hybrid elements. Thereafter, a convenient approach for the identification of spurious zero-energy modes is presented using the positive definiteness property of a flexibility matrix. More- over, based on the orthogonality relationship between the given initial stress modes and the orthogonal basic deformation modes, an alternative method of assumed stress modes to formulate a hybrid element free of spurious modes is discussed. It is found that the orthogonality of the basic deformation modes is the sufficient and necessary condition for the suppression of spurious zero-energy modes. Numerical examples of 2D 4-node quadrilateral elements and 3D 8-node hexahedral elements are illustrated in detail to demonstrate the efficiency of the proposed orthogonal basic deformation mode method.展开更多
Based on the background of "Internet+",after fully sorting and studying on the relevant literature of focus strategy,the paper summarizes the basic modes and influence factors.Choosing the implementation of ...Based on the background of "Internet+",after fully sorting and studying on the relevant literature of focus strategy,the paper summarizes the basic modes and influence factors.Choosing the implementation of focus strategy is the best way to gain the competitive advantage in the narrow market,but not all the enterprises are suitable to choose focus strategy.This paper mainly uses the case study method,Kunming Ch999 is selected as a case study sample,through the resources and capability analysis of Ch999,as well as the comparisons with two e-commerce platforms of Taobao and Jingdong,extracting focus strategy modes of Ch999,the influence factors and risks of focus strategy of Ch999 are also studied.Finally,in order to ensure the smooth implementation of focus strategy,putting forward some risk prevention measures.展开更多
基金Project supported by the National Natural Science Foundation of China(No.10972188)the Fundamental Research Funds for the Central Universities of China(No.2010121073)the Scientific Program of Fujian Province of China(No.2007F3096)
文摘A set of basic deformation modes for hybrid stress finite elements are directly derived from the element displacement field. Subsequently, by employing the so-called united orthogonal conditions, a new orthogonalization method is proposed. The result- ing orthogonal basic deformation modes exhibit simple and clear physical meanings. In addition, they do not involve any material parameters, and thus can be efficiently used to examine the element performance and serve as a unified tool to assess different hybrid elements. Thereafter, a convenient approach for the identification of spurious zero-energy modes is presented using the positive definiteness property of a flexibility matrix. More- over, based on the orthogonality relationship between the given initial stress modes and the orthogonal basic deformation modes, an alternative method of assumed stress modes to formulate a hybrid element free of spurious modes is discussed. It is found that the orthogonality of the basic deformation modes is the sufficient and necessary condition for the suppression of spurious zero-energy modes. Numerical examples of 2D 4-node quadrilateral elements and 3D 8-node hexahedral elements are illustrated in detail to demonstrate the efficiency of the proposed orthogonal basic deformation mode method.
文摘Based on the background of "Internet+",after fully sorting and studying on the relevant literature of focus strategy,the paper summarizes the basic modes and influence factors.Choosing the implementation of focus strategy is the best way to gain the competitive advantage in the narrow market,but not all the enterprises are suitable to choose focus strategy.This paper mainly uses the case study method,Kunming Ch999 is selected as a case study sample,through the resources and capability analysis of Ch999,as well as the comparisons with two e-commerce platforms of Taobao and Jingdong,extracting focus strategy modes of Ch999,the influence factors and risks of focus strategy of Ch999 are also studied.Finally,in order to ensure the smooth implementation of focus strategy,putting forward some risk prevention measures.
