According to the characteristics of a complex cover panel, its geometry shape is described by the NURBS surface with great description capability. With the reference to the surface classification determined by Gauss c...According to the characteristics of a complex cover panel, its geometry shape is described by the NURBS surface with great description capability. With the reference to the surface classification determined by Gauss curvature, the proportion of the mid-surface area between before and after being developed is derived from the displacement variation of the mid-surface in the normal vector direction of the sheet metal during the sheet metal forming process. Hereby, based on the curve development theory in differential geometry, a novel diagonal point by point surface development method is put forward to estimate a complex cover panel＇s blank contour efficiently. By comparing the sample＇s development result of diagonal point by point surface development method with that of available one-step method, the validity of the proposed surface development method is verified.展开更多
The six papers in this special issue of China Population and Development Studies(CPDS)cover an interesting and broad range of topics related to households and living arrangements.Analyzing past trends and making proje...The six papers in this special issue of China Population and Development Studies(CPDS)cover an interesting and broad range of topics related to households and living arrangements.Analyzing past trends and making projections of households and living arrangements are important for understanding important issues such as older adults’care needs,and demands for housing and home-based energy.展开更多
文摘According to the characteristics of a complex cover panel, its geometry shape is described by the NURBS surface with great description capability. With the reference to the surface classification determined by Gauss curvature, the proportion of the mid-surface area between before and after being developed is derived from the displacement variation of the mid-surface in the normal vector direction of the sheet metal during the sheet metal forming process. Hereby, based on the curve development theory in differential geometry, a novel diagonal point by point surface development method is put forward to estimate a complex cover panel＇s blank contour efficiently. By comparing the sample＇s development result of diagonal point by point surface development method with that of available one-step method, the validity of the proposed surface development method is verified.
文摘The six papers in this special issue of China Population and Development Studies(CPDS)cover an interesting and broad range of topics related to households and living arrangements.Analyzing past trends and making projections of households and living arrangements are important for understanding important issues such as older adults’care needs,and demands for housing and home-based energy.
