Applied Mechanics and Materials Vols. 405-408

Abstract: Finite element model which can reflect the effects of different loading positions were constructed with Beam 188. Effects of different restraints, load models and rise-span ratios on out-of-plane buckling were studied by comparing results of fixed arches with that of pin-end arches under three loading models. It is conservative to design by employing results of radial loading. For ideal restraints, out-of-plane stability of pin-end arches is better than fixed arches when rise-span ratio is big. Effects of different loading positions on out-of-plane buckling were studied. Buckling loads of arches which are loaded at arch-axises are bigger than those of top flanges, but smaller than those of bottom flanges.

Abstract: The dissertation taked the ZBS2 straight-line tower in the UHV line project as the object,used the finite element software ANSYS to establish finite element model and did a analysis about its dynamic characteristics. Considering width and thickness of large width angle steel,the section area of large width angle steel is larger than normal angle steel,and the application of large width angle steel can increase bearing capacity of the member.Therefore,this article taked large width angle steel to replace double combined angle steels in the main members of the tower,and calculated the ultimate bearing capacity. Analysis of comparison indicate that the ultimate bearing capacity increases by 13% when large width angle steel is used.Therefore it is feasible and advantageous that large width angle steel uses in the UHV transimission tower,and it provide a reference and basis for future design of the UHV transmission tower with large width angle steel.

Abstract: By using Mukis method, the dynamic interaction between the pile group and layered poroelastic half space subjected to axial harmonic loads is investigated in this study. By using Mukis method, the second kind of Fredholm integral equations describing the dynamic interaction between the layered half space and the pile group is constructed. Numerical solution of the integral equation yields the axial force, the displacement of the pile as well as the response of the layered poroelastic half space. Results of this paper are compared with known results, which shows that our solutions is in a good agreement with the known result. The numerical results of this study also demonstrate that the soil inhomogeneity has a significant influence on the response of pile group.

Abstract: A new kind of RC frame-shear wall structures with partial columns sliding at upper ends is proposed in this paper. A shaking table test of this new kind of structure model (Model B) and a conventional frame shear-wall structure Model (Model A) were carried out, and the plan layout and the member size of the two models are nearly identical. The two models are 3-story and 2-bay by 2-bay, and the second story of either structure is weak story. The test results showed that: (1) under the same intense earthquake, the damage of Model B is slighter than that of Model A; and (2) under the same intense earthquake, the interstory drift angle, the acceleration and the shear force of weak story of Model B are reduced remarkably in comparison to Model A.

Abstract: A three-dimensional (3D) flow mathematical model has been applied to simulate the flow field around spur dikes. In the vertical plane, the z-coordinate was adopted, and the additional layer was used to track the free water surface. The standard k-ε model was adopted, additionally, wall function and large coefficient method was applied to treat the boundary of the spur dike. Simulated results of velocity distribution, turbulent kinetic energy and its dissipation rate around the spur dike agree well with the experimental data.

Abstract: Two two-side constraint steel plate shear wall specimens with vertical stiffeners had been tested under low cyclic loading to study its seismic performance through the performance indexes of the Initial stiffness, hysteretic behavior, load-carrying capacity, destruction mechanism and so on. Test showed that as main lateral force resisting members two-side constraint steel plate shear wall with vertical stiffeners had a very superior seismic performance. So it is worth popularizing in the area of high seismic intensity.

Abstract: This paper focus on the model updating of civil structural systems. Traditional modal test method can identify the frequency of the civil structure accurate, but it is difficult to identify the mass-normalized mode shape. By adding a series of known masses to the structure, measuring the frequency of this mass-modified system, and only using this set of frequency data, the mass-normalized mode shape of the structure can be identified. And the model updating method was developed, which constructed an objective function through the frequency of the measurement and the FE model, corrected the FE model's parameters to minimize the objective function. The example was included to show the capabilities of the technique. The finite element model of the fixed-free beam was updated by the dynamic characteristics which was identified from the modal test, the results show that updated results coincided with the experience of the analyst.

Abstract: The bonding problem of interface between the fresh and old concrete is one of the main technological difficulties in the Heightening Project of Danjiangkou Dam in the South-to-North Water Diversion Project. At present, no mature experiences or engineering examples are found in China for concrete dam heightening. Because of the external environmental impacts of temperature change, aging and hydraulic fracturing on the interface between the fresh and old concrete, crack is likely to occur, which brings risks to the safe operation of the dam. In this article, the finite element direct force method was used to calculate the internal force. The safety of No. 1 dam monolith was calculated in accordance with the standard method for gravity dam in three conditions of fresh-old concrete bonding interface, i.e., perfect condition, cracked interface and cracked interface with water seepage. Suggestions for their solutions were also provided.

Abstract: With perfect mechanical property and excellent resistance to corrosion and environment degradation, Carbon fiber reinforced composite is widely used in the strengthening of metallic structures. It can improve the static behavior of steel beam, prolong fatigue life. This paper summarizes the following areas that have received many researches: the increase of moment carrying capacity, the distribution of interfacial stress, the extending of the fatigue life of structural steel elements, which can be useful for the engineering application or further researches.

Abstract: Explosions, such as a bomb explosion and a gas explosion, can cause catastrophic damage on the buildings. In fact, an explosion may result in large dynamic loads, greater than the original design loads, of many structures. Two RC specimens were tested under explosive loading. The first specimen was used as a control for the experiment, while the other was retrofitted with 6 near surface mounted (NSM) Carbon FRP strips on each face. Both specimens were subjected to a 60g Pentolite at stand off distances of 0.6m. The aim of this experiment was to observe and compare the behavior of the two specimens, and their ability to resist blast loads respectively. Of particular interest was the response of the retrofitted RC specimens NSM Carbon FRP. The experimental results showed that NSM retrofitting with Carbon FRP is an effective way to provide extra strength when retrofitting against blast loading.