Applied Mechanics and Materials Vols. 744-746

Abstract: The calibration of the concrete-rebar detection system use the calibration components made by the various metrological verification units commonly,and the value cannot be traced back.In this paper, the development principles of the calibration components is analyzed systematic. The position of the reinforced bar on the influence of the result of the test was tested by using the HC - GY61 reinforced location tester,from which come to a conclusion of the design reference of Φ12,Φ16,Φ20 and Φ25 while the value error is in ±1mm and 0mm,which also can provide a reference for industries developed calibration components.

Abstract: In this paper, based on accelerated testing indoors, under the action of bending tensile stress on a marine high-performance concrete chloride ion diffusion coefficient, the results show that: Subjected to bend under the action of tensile stress and do not withstand the test piece chloride diffusion coefficient increases with increasing stress levels, different tensile stress and does not bear the stress of the concrete chloride ion diffusion coefficient ratio (D_η/D₀) exponential relationship with the stress level (η). In addition, addition, for a domestic Bridge, preliminary design to determine typical parameters of components and their environment is proposed to consider the durability of concrete structure load control index calculation method, to establish a "design life - chloride ion diffusion coefficient controlled targets" the correspondence between, for similar projects designed to provide a reference durability.

Abstract: After steel structure was added on top of a concrete frame structure, the mass, stiffness, natural period and damping ratio of the original frame structure has changed significantly. Using finite element software ANSYS and software PKPM respectively, model of the original frame structure and the new structure with story-adding steel structure were built. Furthermore, seismic performance of the three structures was studied. Weak location of the structure was found out. Finally, the main factors were analyzed. Results show that whiplash effect is not obvious when one-story steel structure was added on the top of the original frame structure. Also, seismic performance of the frame structure with two-story steel structures on the top is perfect. Some suggestions are put forward for designing the similar structure.

Abstract: The Finite Particle Method (FPM), based on the Vector Mechanics, is a new structural analysis method. This paper explores the possibility of the proposed method being applied in the dynamic nonlinear analysis of semi-rigid steel frames. Taking the two dimensional beam element as an example, the formulations of the FPM to calculate the dynamic and geometric nonlinear problems are derived. Spring model with zero-length is adopted to simulate the relationship between internal forces and deformations of the semi-rigid steel connections. The nonlinear strengthen spring model is used to analyze the nonlinear behavior of the semi-rigid connection. Explicit time integrations are used to solve equilibrium equations. Comparing to traditional Finite Element Method, iterations and special modifications are not needed during the dynamic nonlinear analysis, which is more advantageous in structural complex behavior analysis. Two numerical examples are presented to analyze the behaviors of rigid and semi-rigid steel frames, and behaviors of linear and nonlinear semi-rigid connections, which demonstrate the accuracy and applicability of this method in dynamic nonlinear analysis.

Abstract: The effects of silica fume (SF) on compressive strength of concrete have been analyzed. The compressive strength results of concrete mixed over different water–binder ratios as well as different replacing percentages of SF were analyzed. The results of the experiments showed that when the polymer/binder materials ratio increases, the compressive strength of concrete decreases. A mathematical model has been proposed for evaluating the strength of concrete containing SF. The proposed model provides a probability to analyze compressive strength based on the time of curing in water (t), water to binder materials ratios and SF to binder materials ratios which are shown as (w/b) and (s). This model might serve as a useful guide for increasing concrete compressive strength.

Abstract: The evaluation on dynamic responses of transmission lines subjected to wind excitations is actively carried out in this study. A transmission tower-line system constructed in the southern coastal areas of China is taken as example to examine the wind induced response of the transmission lines. The structural model is established based on finite element approach by using commercial package. The displacement, velocity and acceleration responses of the transmission lines are computed to explore structural performance. The made observations indicate that the transmission lines vibrant substantially when subjected to strong winds. It is obvious that the dynamic responses of the ground wire are smaller than those of the wire and the responses in the long span are much larger than those in the short span.

Abstract: This issue conducted the low cyclic reversed loading test of 3 groups of framework joints formed by inorganic anchorage materials and 1 group of the one formed by integral concreting. This paper study the seismic performance, analyzed the hysteretic curve, bearing capacity, ductility and the capacity of energy dissipation of the framework joints. The conclusion can be obtained that the bearing capacity of framework joints connected with strengthening planting bar are better than the ordinary joints. The ductility and seismic performance are good.

Abstract: Seven axially square CFRP steel tubular confined recycled aggregate concrete long columns were experimentally investigated to study their static behavior. The influence of the slenderness ratio, recycled coarse aggregate replacement ratio, layers of CFRP jackets effect on the performance of axial compression. The test results show that the higher the recycled coarse aggregate content and the slenderness ratio, the greater the specimen ultimate bearing capacity is smaller, and the more the layers of CFRP jackets, the greater the specimen ultimate bearing capacity.

Abstract: In order to further promote the use of recycled aggregate concrete in practice, axial compression tests were carried out for 7 CFRP circular steel tubular confined recycled aggregate concrete columns. The influence of the replace rate of recycled aggregate concrete, the wrapping method on axial compression behavior of CFRP circular steel tubular confined recycled aggregate concrete columns were analyzed. Based on the results of the tests, with the replace rate of recycled aggregate concrete increasing, the specimens have an decreasing trend in the load bearing capacity. The whole CFRP wrapping circular steel tubular confined recycled aggregate concrete columns have higher load bearing capacity than the three stripe wrapping ones.

Abstract: Four prestressed high strength concrete pipe piles were tested under low cyclic loading, the failure characteristic, bearing capacity, ductility performance and hysteretic characteristic were analyzed. The research show that the bearing capacity and the ductility performance could be improved a lot by two measures of adding non-prestressed reinforcement and filling the pile core. The hysteresis loop of pile specimen adding non-prestressed steel bars is fuller, the energy dissipation capacity is larger, and the hysteretic behavior is better.