Advanced Materials Research Vol. 700

Abstract: China is developing overseas construction projects, it is necessary for the designers to grasp codes. This paper compares and analyzes Chinese code GB50009-2001, American standard ASCE/SEI7-05 and British standard BS6399-2 about advanced structure. And the writer calculates the empirical projects' wind-loads by Chinese code, American standard and British standard, compares the difference and points out the deficiency of domestic code. So as to improve the designers to master different wind load standards and promote the improvement of inland standard.

Abstract: Early in the 20th century 70's, the concept of energy-saving building was officially proposed. The core of energy-saving buildings is to reduce energy consumption and enhance energy efficiency in buildings. However, with the continued rapid growth of China's economic and urbanization high-rise buildings have become the mainstream of the building industry. So, the research on energy-saving design in high-rise buildings in advanced structure becomes the hot issue of general interest. Many advanced structures and building materials have constantly developed, and have been used in high-rise buildings energy efficiency design. This paper summarizes and prospects the current situation of energy-saving design in chinas high-rise building, and also provides a reference for hoping the energy-saving design can be geared to international standards better.

Abstract: This paper takes the CNC broaching machine as the research object. The dynamic models for the various components of the broaching machine are established. The theories of the modal analysis and the dynamic performance are studied respectively. According to the analysis results, the improvement schemes on the partial structures or geometries are put forward. At the same time, the paper also studied preliminarily the dynamic characteristics of the CNC broaching machine. During the analysis process, the models of the parts and the whole model are established using the finite element method to optimize the structures of the parts and the whole. That has undoubtedly a very important significance for improving the dynamic performance of the new machines structure, improving the processing accuracy, shortening the development cycle and reducing the development costs.

Abstract: Influence function method is a common method to calculate the roll system deformation. It solves after discretizing the rollers load and elastic deformation, but the traditional influence function method doesn't consider whether the width of the rolled piece is equal to the integral multiple of the divided units length, therefore it only can solve approximately, which affects the calculation accuracy. According to the accuracy loss problem of the traditional algorithm, the paper puts forward a solution with advanced structure to deal with the left rolled pieces after division. The solution self-adapts the width changes of the rolled pieces, which not only avoids the problems of increasing the segmentation unit quantity to reduce the influence by edges and reducing the calculation speed of the traditional influence function method, but also improves the calculation accuracy of the model, and raising the level of material properties control.

Abstract: Carbon fibers with different surface structure are obtained by changing the level of anodization, and have the carbon fiber and epoxy resin processed into carbon fiber-resin matrix composite. Relationship between chemical structure of carbon fiber and moisture absorption property of composite in hot and humid environment is studied. The experiments show that the surface activity of carbon fiber increase significantly after anodization treatment, and there are a large amount of increase for oxygen-containing functional groups in fiber surface, in particular to OH which increase from 17.92% to 33.25%. The moisture absorption mechanism differs in varied conditions of heat and humidity, and temperature is an important factor affecting composites hygroscopic property. The higher the carbon surface activity is, the bigger the equilibrium absorbent moisture would be, and the increase of which would cause an obvious decline in inter-level shear strength (ILSS) value of carbon fiber-epoxy composites.

Abstract: In this paper, carbon fibre fabric reinforced polymeric composites with the capability of self-healing were studied. These fabric-composite laminates were fabricated by hand lay-up of plain weave (PW) carbon fibre fabrics impregnated with polymer blends of epoxy resin and thermoplastic healing agent. Laminates containing different amounts of healing agent (0, 10wt% and 20wt% by weight of epoxy) were evaluated by tensile and three-point flexural tests according to the ASTM D3039/D3039M and D790, respectively. Aside of the potential for self-healing, benefits were found in terms of tensile and flexural properties. Overall, tensile properties were improved with addition of thermoplastic healing agent; the highest tensile strength and failure strain were obtained with the highest healing agent amount (20wt%) whilst the maximum tensile modulus was obtained at 10wt%. In general, flexural properties were also improved except flexural strain; the highest flexural strength and modulus were determined at 10wt%.

Abstract: Based on Mohr - Coulomb failure criterion, dynamic strength characteristic of undisturbed loess in Xining, Lanzhou, Xiji and Xian was studied through dynamic triaxial test. And the regional characteristics of void ratio, natural moisture content, plasticity index and dynamic shear strength with different vibration frequency and natural conditions were analyzed. The research shows that dynamic shear strength of loess increases when consolidation stress rises under the same water content condition. However the increase trend is not proportional relationship. Initial void ratio and water content of loess under natural state rises from northwest to southeast, and dynamic cohesive force enhances. On the contrary, internal friction angle decreases with the change of characteristic. With the increasing trend of disturbed loesss clay content from northwest to southeast, dynamic cohesive force increases and internal friction angle decreases in the different amplitude. The conclusion enriches and develops the evaluation theory of loess regional dynamic characteristic and it is a universal method to reduce cost of different loess regional classification.

Abstract: In this paper, a new type of vertical scrubber is designed and a computational fluid dynamic analysis of gas flow through the device is presented. The simulation results are obtained by FLUENT 6.3. Through the two-dimension simplification of mist-mat, the resistance characteristic of the wire-mesh is gained. To simulate the gas flow of the scrubber, mist-mat is replaced by porous media. Through the analysis of simulate results, flow characteristic and pressure drop of the scrubber is obtained. Additionally, CFD analysis results show the entrance direction of the gas in vane inlet symmetry plane is benefit to avert severely velocity impulse and scrubber’s pressure drop rises with the growth of the eliminator’s velocity.

Abstract: This paper establishes finite element model of the spreader based on ANSYS, simulating its mechanical properties: static strength and modal vibration. Based on the calculation results, it points out the weaknesses of the spreader under more cases and its vibration characteristics, in addition, we also discuss the impacts on environment and human body from the perspective of ergonomics, which can provide theoretical basis for further fatigue life and dynamics research.

Abstract: S elbow in Zhijing River is one of the key parts in the East Gas Transmission Pipeline Project. It brings a great deal of uncertainty and risk factors for pipeline pigging operations. By analysis on dynamic of pig pigging and the impact over bending, this paper established the finite element model, simulated pigging process on the condition that the operating parameters of the pipeline pigging operations were given, analyzed the relationship among pipeline pressure, foam pigging speed and pipe stress, then obtained the security of pipeline pigging operations.