Applied Mechanics and Materials Vols. 351-352

Abstract: Seismic performance of RC beam-column joints under low cyclic loading with different cycle numbers was analyzed by FEA software, to study duration effect of long period ground motion. The loading with different cycle numbers was used to simulate the duration of the ground motion. Hysteretic curves and skeleton curves of the joints were obtained. The results indicate that as the cycle number increases, the capacity and ductility of the joint declines, and the stiffness of the joint attenuates faster.

Abstract: By way of the soaking and drying cycle test on the different mix proportions vertical section of 10 pieces of RC beams suffered artificial sea water (ASW) corrosion under0,35,70,105,140 times of dry-wet cycles, the compared result of exerting pressure test of these beams under simply supporting were investigated. The law was as follows: The resistibility to ASW corrosion for the concrete specimens with various water cement ratio (various initial strength) are different;The characters of normal section failure for RC beams attacked by sea water are about the same as that for ordinary RC beam; Along with the extension of the time for seawater attack, the bearing capacity for normal section of RC beams varies wave upon wave. The specimens attacked by seawater for about 35 times of corrosion cycle achieve minimum bearing capacity.

Abstract: This paper, the mechanics characteristic of T-shaped section steel reinforced concrete column under low period repeated loading by using large-scale finite element analysis software ABAQUS was analyzed, combined existing research, the influence of the performance of ductility under different steel ratio and axial compression ratio was studied, we concluded that the T-shaped section steel reinforced concrete column has the very good ductility performance, and put forward the axial compressive ratio limit under the different parameters, and to provide the reference for future research and application.

Abstract: In this paper,in order to study the load-bearing capacity of frame columns with construction joint under low-cyclic reversed loading, nine specimens were made, divided into three groups.Every group had three specimens, the first were made without construction joint, the second had fine processing construction joint, the third had simple processing construction joint. The three groups were loaded in axial compression ratio of 0.23,0.34,0.46 respectively.The results show that the influence of different processing with construction joint to crack position ultimate bearing capacity,skeleton curves.

Abstract: The way of pre-reserving oval bolt hole in steel plate support design in space grid structure so that it can provide lateral stiffness for the structure is a common practice. However, the details about this plate support cant be found in related codes. As a result, what effect this kind bolt hole could influence on the mechanical performance of the support needs to be further studied. In order to solve this problem, a common used plate support with oval bolt holes is discussed. The contact between the bolt and the hole, the bolt cap and the plate, the bottom plate and the base plate is established respectively with the ABAQUS/Standard, which is to analysis the impact of the oval bolt holes on the load capacity and lateral stiffness of the steel plate support.

Abstract: To increase the computation efficiency of the three-dimensional nonlinear dynamic analysis of soil-structure, the liner-nonlinear mixed constrained mode synthesis method was put forward according to the characteristic that the structure owns local plastic region, which is appropriate for both nonlinear substructure and multi linear substructures with boundary coupling. Divided the whole system into linear substructure and nonlinear substructure, this method reduced the freedom degree of linear substructure according to the potential energy criterion and finally synthesized them with the nonlinear substructure, thus obtaining the dynamic response of nonlinear system. The accuracy and effectiveness of this method were proved by further applying this method in the three-dimensional dynamic analysis example of soil-high building interaction system to carry out dynamic time-history analyses under the effect of multi-groups earthquake incentives respectively for two different boundary conditions of soil mass. Finally, several groups of numerical experimentations were conducted based on the various different values of nonlinear soil mass region, and the result indicated that as far as the example of this paper was concerned, it can obtain satisfiable computation result when the range of nonlinear soil mass region was 3 times of the horizontal size of upper structure, which further demonstrated the effectiveness of the method proposed in this paper.

Abstract: The theory calculation method, test methods and experience formulas of reinforced concrete column equivalent plastic hinge length are summarized firstly. The limit state is defined as the constraint concrete to ultimate compressive strain. Finally, the simplified calculation method of equivalent plastic hinge length is proposed.

Abstract: Quasi-static test on a half-scale two-story masonry model was carried out to study the seismic strengthening performance and damage characteristic of existing masonry school buildings. The wall piers between openings were partially strengthened with steel mesh mortar splint where the steel mesh is reliably anchored using vertical reinforcements. The results show that strong pier-weak spandrel failure mechanism is guaranteed due to the formation of global failure mechanism. The failure characteristic, energy dissipation capacity and load bearing capacity of masonry structure are significantly improved.

Abstract: Established the three spans prestressed continuous beam dynamic equation, obtained analytical expression of frequency equation. To solve the frequency equation for natural frequency, and compared with the finite element numerical analysis results, the frequency both with analytical expression and with finite element are in good agreement. The formula can be obtained accurately the dynamic parameters of three spans prestressed continuous beam such as frequency. At the same time, the paper also studied the natural frequency sensitivity analysis of three spans prestressed continuous beam, and focuses on the impact on the frequency with effective prestress and prestressed eccentricity.

Abstract: Lots of bulidings had collapsed in Wenchuan big earthquake in 2008, one important reason is that the structure design has been launched only in X or Y axis of the building respectively, which means the oblique direction compression-bending characteristic has not been fully considered in the actual structure design process. In addition, the moment bearing strength in oblique direction is smaller than the moment strength about the principle axis of the column, so the research on bending strength calculation of biaxial/oblique compression-bending RC column is important to improve the aseismic safty of the buildings under actual earthquake effects. In this paper research achievements about bearing capacity calculation of column under oblique compression-bending action are summarized and analyzed. At last the advice for actual application has also been given.