Advanced Materials Research Vols. 243-249

Abstract: Nondeterministic Linear Static Finite Element Analysis: An Interval Approach A Thesis Presented to The Academic Faculty By Hao Zhang School of Civil and Environmental Engineering Georgia Institute of Technology December 2005

Abstract: As modern materials and techniques are widely used in the countryside, the living environment which is peculiar to traditional vernacular buildings is damaged. Then the buildings and the construction technology are at risk of elimination and extinction. This paper takes seaweed house as typical example, attempting to explore how the vernacular buildings develop in an original, plain and ecological way.

Abstract: Kang Bai-wan’s Mansions is one of the three famous landlord manors in China; it is located at Kangdian town in Gongyi city, Henan province; it is a large architectural complex built in Qing Dynasty. This paper will research on the general layout, courtyard environment and cave dwelling building of Kang Bai-wan’s Mansions from the ecological perspective, to explore the ecology philosophic thought and local structural techniques contained in the traditional Chinese architecture and to point out that the combination of tradition and modernity is the main road for the Chinese ecological buildings development.

Abstract: At present, there’s unbolt independent system of green assessment concerning construction process, let alone a sub –part engineering. In this paper, based on grey clustering method and evaluating model of green construction studied previously, the evaluating index system of green construction is proposed with the addition and deletion of indexes in term of wall project. Finally, methods of evaluation will be applied to the two actual engineering schemes for evaluation. The conclusions will be compared, showing the method is more feasible.

Abstract: The current domestic exterior insulation system fire incidents are frequent. The study of exterior insulation system fire performance gets more and more relevant national authorities and insiders' attention. Based on two sides wall exterior insulation system as the research object, fire prevention experimental research method of insulation system and the insulation system temperature spread rule are expounded. Reveals the insulation system burning speed and scope of the fire from spreading under the action of the fire. The temperature and temperature field change regularity and insulation system of damaged situation after combustion are compared, and structural measures to improve the insulation system fire performance role is drawn.

Abstract: There are many factors affecting segregation of self-compacting concrete, and one of major factors is aggregate size. Based on the application of Stokes law to analyze aggregate segregation, ball-drop paste viscosity measurement has been used in the research that segregation degree of aggregate of various particle size in paste of identical paste consistency and the relationship between aggregate size and paste viscosity when concrete mixture reach the same fluidity in this article. It shows that aggregate segregation rapidly grows up with the increase of aggregate size and in order to reduce aggregate segregation, paste viscosity should be increased correspondingly under identical fluidity; as the aggregate size comes up to a certain degree, the growth of paste viscosity speeds up obviously, for the sake of maintaining the fluidity, paste should be increased; there is a sudden change in the growth course curve that paste viscosity increases with the aggregate, from the perspective of aggregate segregation, the part before the change has been approved to be a reasonable size range of the aggregate.

Abstract: In Lhasa city, because of the abundant solar radiation, different direction walls absorb very different amount of solar energy. For the more efficient using of solar radiation, this difference should be reflected in the insulation design. By analysis on the typical year climate data, the absorption of solar radiation of different direction walls is clear. Compared with the inland city, Lhasa has more abundant solar energy and the bigger difference of direction, which means, the non-balance insulation is meaningful. The local test verifies the result of south and north room’s big difference thermal environment in the target building. By analyzing the permissible value of net heat loss by the envelope, the suggested limited value of overall heat transfer coefficient is proposed.

Abstract: The louver affects natural ventilation rate and indoor air distribution. In this paper, the wind velocity profile and pressure distribution in the natural ventilation model building were simulated through CFD. And how different rotation angles of the shutter and different incidence angles of the wind affect natural ventilation rate were studied. Then, the influences of shutters on the discharge coefficients were analyzed, and use principles of the louver equipped in the building were proposed.

Abstract: The paper proposed a new system of spatial structure: steel- concrete composite ribbed shell, and briefly compared the three analysis methods considering the initial imperfections of structures: the random imperfection mode method, the consistent imperfection mode method and the improved random imperfection mode method. By using of the consistent imperfection mode method and nonlinear finite element analysis software ANSYS, we analyzed a composite steel-concrete ribbed shell with the span of 40m and span ratio f/L=1/4, which is simply supported at its surrounding and is subjected to uniform loading along it’s whole span. The critical load and instability regions of this shell are presented. The results show that with the increasing of the initial imperfections, the value of critical load decreased from 27% to 36%; the trend of load-displacement curve and the location of structural instability regions remain unchanged, only the shape of instability regions will change. This indicted that the effect of the initial imperfections within composite ribbed shell is far less than its influence to the single-layer shell. The steel-concrete composed ribbed shell is not sensitive to the initial geometric imperfections and shows a strong post-buckling performance.

Abstract: The steel-concrete composite ribbed shell is a new type of spatial structure. Different restrained boundary conditions have a considerably influence on the ultimate bearing capacity and stability. Based on the nonlinear finite element method, a numerical model is made by finite element analysis software ANSYS, in which material and geometrical nonlinear are considered. A spherical composite ribbed shell with 40m span, three different section dimensions and two different vector heights is used as an example, in which 4 different restrained boundary conditions are considered, including all fixed, all hinged, node fixed and node hinged. The results show that when the section dimension and span height are the same, the ultimate bearing capacity will be greater as the boundary becoming rigid, and when the section dimension is larger, the ratio of ultimate bearing capacity under different restrained boundary conditions is increasing, while as the span height is greater, the ratio is decreasing. To the instable shape, the influence of different restrained boundary is minor, all the instable modes are extreme point instability, but the trend of load-displacement curves are almost similar, and when the cross-section dimension of composite rib increases, the composite ribbed shell under different boundary constraints has shown higher post-buckling strength.