A new model for self-diffusion coefficients was proposed based oil both the concepts of molecular free volume and activation energy. The unknown parameters of this model were clearly defined and compared with the Chap...A new model for self-diffusion coefficients was proposed based oil both the concepts of molecular free volume and activation energy. The unknown parameters of this model were clearly defined and compared with the Chapman-Enskog model. At the same time a new method for calculating activation energy was devised and applied to the new model. In addition, the free volume was defined by implementing the generic van der Waals equation of state, the radial distribution function of which was obtained by using the Morsali- Goharshadi empirical formula. Under the same conditions, the new model was better than the original free volume model.展开更多
In a soft clay layer overlain by a thick man made ground layer, as in the case of the Unkapam shores of the Golden Horn, excess pore pressures have remained for long periods and the soft clay layer has hardly undergon...In a soft clay layer overlain by a thick man made ground layer, as in the case of the Unkapam shores of the Golden Horn, excess pore pressures have remained for long periods and the soft clay layer has hardly undergone few volumetric deformations. Along the shores of the Golden Horn such creep of the soil towards the sea has been detected at more than 40 mm in the last 26 months. The measurements of those movements are examined in this paper. Our research points out that the local failure of a soil element or of a particular layer differs from the general failure of the soil mass. Furthermore, the large masses of unfailed soil which overlie the soft layer along the shores of the Golden Horn delay the general failure of the slopes. We conclude that the shear strains producing excessive pore pressures is the cause of the creep observed. Because a proper solution still need to be found for a sustainable stability of the area, it is necessary to continue with the measurements of the Golden Horn＇s creeping shores.展开更多
本文基于固体各向同性材料惩罚(solid lsotropic material with penalization,SIMP)插值模型提出一种考虑几何非线性效应的多相多孔结构拓扑优化设计方法。通过控制不同材料相的局部体积分数来形成多相多孔结构,利用p-范数将多个局部体...本文基于固体各向同性材料惩罚(solid lsotropic material with penalization,SIMP)插值模型提出一种考虑几何非线性效应的多相多孔结构拓扑优化设计方法。通过控制不同材料相的局部体积分数来形成多相多孔结构,利用p-范数将多个局部体积约束聚合为一个全局约束函数,以减少优化问题中的约束个数。采用附加超弹性技术避免几何大变形下的网格畸变问题。最后两个优化算例验证了本文方法的有效性,结果表明:本文方法可以实现不同材料相之间的合理分布,考虑几何非线性效应的多相多孔结构的位移、应力均更小。相比于单材料,考虑多相材料的多孔结构具有更好的性能。展开更多
文摘A new model for self-diffusion coefficients was proposed based oil both the concepts of molecular free volume and activation energy. The unknown parameters of this model were clearly defined and compared with the Chapman-Enskog model. At the same time a new method for calculating activation energy was devised and applied to the new model. In addition, the free volume was defined by implementing the generic van der Waals equation of state, the radial distribution function of which was obtained by using the Morsali- Goharshadi empirical formula. Under the same conditions, the new model was better than the original free volume model.
文摘In a soft clay layer overlain by a thick man made ground layer, as in the case of the Unkapam shores of the Golden Horn, excess pore pressures have remained for long periods and the soft clay layer has hardly undergone few volumetric deformations. Along the shores of the Golden Horn such creep of the soil towards the sea has been detected at more than 40 mm in the last 26 months. The measurements of those movements are examined in this paper. Our research points out that the local failure of a soil element or of a particular layer differs from the general failure of the soil mass. Furthermore, the large masses of unfailed soil which overlie the soft layer along the shores of the Golden Horn delay the general failure of the slopes. We conclude that the shear strains producing excessive pore pressures is the cause of the creep observed. Because a proper solution still need to be found for a sustainable stability of the area, it is necessary to continue with the measurements of the Golden Horn＇s creeping shores.
文摘本文基于固体各向同性材料惩罚(solid lsotropic material with penalization,SIMP)插值模型提出一种考虑几何非线性效应的多相多孔结构拓扑优化设计方法。通过控制不同材料相的局部体积分数来形成多相多孔结构,利用p-范数将多个局部体积约束聚合为一个全局约束函数,以减少优化问题中的约束个数。采用附加超弹性技术避免几何大变形下的网格畸变问题。最后两个优化算例验证了本文方法的有效性,结果表明:本文方法可以实现不同材料相之间的合理分布,考虑几何非线性效应的多相多孔结构的位移、应力均更小。相比于单材料,考虑多相材料的多孔结构具有更好的性能。
