Advanced Materials Research Vols. 446-449

Abstract: In order to solve the problem that need exact and scientific data in checking and restoring cultural relics, this paper presents a novel algorithm that statistics defect areas of cultural relics by calculating holes area in the in triangular mesh models.First, build the topological relationship between triangles, vertices and edges and extract boundary using boundary property of triangular mesh. Next, the holes bounding edges are linked in sequence into holes polygon. Finally, distinguish holes boundary and model exterior boundary by means of triangular mesh topological characteristics and the areas of three-dimensional holes polygon are calculated to statistics defect areas of cultural relics through the method of coordinate. Through experiments, it proved that this algorithm was correctly and reasonable.

Abstract: Adhesive anchors are widely used as post-installed fasteners in civil engineering. A typical steel-to-concrete connection includes multiple anchors which are commonly subjected to combined moment and shear loading. Based on the assumption that all anchors take up shear load, a revised method is developed for the design of ductile anchors, which considers that only the row of most stressed anchors in the tension zone are needed to meet the elliptical interaction of tension and shear capacity requirement during the design process of anchorage group under combined shear and moment loading. The ultimate strength of post-installed fastenings should be controlled by the strength of anchor steel for the purpose of connection safety and full utilization of anchor capacity. For the objective of ductile design in anchor group, the ratio of shear span could be used as an evaluation parameter in the process of strength prediction. According to the theoretical analysis and results comparison, the ductile failure of anchor steel in post-installed fastenings can be guaranteed when the ratio of shear span is greater than 0.6.

Abstract: External corrosion is a corrosion phenomenon due to the environment or surrounding of the structure. This paper discusses on the influence of chloride and sulphate element on corrosion resistance of steel coupon buried underground. The coupons were placed underground at seven different locations of various soil compositions covering east-coast of Peninsular Malaysia. A total of 132 of steel coupons were installed in a 1.0m-hole and exposed to the subsoil environment for a period of 12-months whereby a periodic retrieval of the coupon were done for every 3-months so that the dynamic growth of metal loss can be measured continuously over time. Soil resistivity test were conducted on the selected sites to determine its corrosiveness level. Parameters such as sulphate and chloride content were measured to correlate with the actual metal loss of buried steel coupons. Site with the highest content of chloride and sulphate yields the most severe loss of metal volume. The findings show that chloride and sulphate contents are highly influential upon corrosion growth rate.

Abstract: This work shows the results of monitoring of Santa Maria del Suffragio (Anime Sante) church, L’Aquila, Italy. The historical building was stricken and damaged by mainshock of April 6, 2009; the dome is the structural element that has been seriously hit by seismic event. The ambient response analysis of global structure and dome element enable to improve the FE model by model updating methodology using modal data. The identification techniques furnish useful information concerning the structural and mechanical properties of dome’s structure, these parameters are needed to evaluate the appropriate design of rebuilding and structural rehabilitation of dome. The geometric configuration and the self-weight of lantern induce to an independent dynamic response of macro-element against the behaviour of dome generating the first mechanism of collapse and the failure of dome shape. Different retrofitting configurations for the dome have been proposed in this paper.

Abstract: Frequency variable TMD system is developed based on the conventional TMD system, which has multiple frequencies and thus merits of MTMD. Frequency variable TMD can effectively reduce the dynamic response of structure induced by its own frequencies. In this study, this technique is applied to dynamic analysis of high-rise building. The results show that frequency variable TMD system can optimize the dynamic response of the structure and control the vibration effectively, compared to conventional TMD system.

Abstract: Based on brief introduction of the vibration control theory of tuned mass damper (TMD) and its development course, this paper puts forward the basic method in model analysis of TMD for vibration control under wind load in high-rise buildings. After analyzing the recent applications of TMD in high-rise buildings at home and abroad, the developing trend and problems to be solved in TMD design and construction are also pointed out.

Abstract: The welding joint method is usually applied in the reinforcing process of the steel moment frame connections. The welding parameters are chosen and discussed and the finite element analysis is employed to analyze the completely penetration joint weld between the flange plates and the column flange. The three-dimensional thermo-structure simulation is conducted. Furthermore, the influence of the residual stresses on the the loading capacity of the reinforced connection is discussed. The temperature field during the welding process and the residual stresses distribution are given. The existence of the welding residual will highly increase the likelihood of brittle fracture of the steel in the heat affect zone.

Abstract: Based on existing methods and results of other research, the bond-slip relationship model is given and the distrubition of shear stress of concrete beam strengthened by FRP in salt water is derived. Through a specific example to analyze the distribution of interfacial shear stress, and the different effects caused by different aggressive environment on the interfacial properties. The results show that: 1) Interfacial shear stress will sharply reduce with increasing distance from the end; 2) Different environments have different effects on the interface properties of FRP strengthened beams. Salt water erosion influnce the interfacial properties of FRP strengthened beams significantly.

Abstract: In order to study the seismic behavior of post anchored RC members with different anchoring materials, such as the ductility, load carrying capacity, energy dissipation, etc, eight RC column joint specimens were designed and tested under repeated cyclical load. Comparing the test result with existing findings, it has shown that column members with organic adhesively bonded rebars which anchorage length is more than 15D, have good carrying capacity, ductility and energy dissipation capacity. Due to the inorganic material is short of deformability, it could satisfy the demand of seismic behavior when the anchorage length is lager than 20D.

Abstract: Corrosion inhibitor have a significant influence on corrosion rate of marine concrete. In this paper, linear polarization method is used in reinforced concrete that under marine environment, and reinforced concrete is mixed with corrosion inhibitor. The results show that: corrosion inhibitor has a little influence on the basic mechanical properties of reinforced concrete, and it can effectively improve the corrosion resistance ability of reinforced concrete. For reinforced concrete of the same corrosion inhibitor content, with the decline of water-cement ratio, the steel corrosion rate descends; in a certain content range , with the increase of corrosion inhibitor content, the corrosion rate of reinforced concrete decreases evidently.