Bearing Capacity Of Components Research Articles

Seismic design method based on limit state for prefabricated RCS frames

The prefabricated reinforced concrete column-steel beam (RCS) frame is an innovative and efficient structural system. To promote the application of the prefabricated RCS frame, a practical seismic design method based on the limit state design was proposed. The elastic method based on the bearing capacity of components was adopted to design frames with different ground motion intensities. When the designed frames are under the strong-column-weak-beam criterion, the capacity and demand values of over-strength factors were calculated, and the over-strength factors were adopted to calculate the yield base shear. Based on the yield base shear and yield mechanism, the semi-rigid connections were designed according to the plastic method, while the beams and columns were designed based on the capacity method. The proposed design method was successfully applied to a six-story prefabricated RCS frame and validated by inelastic analyses. Furthermore, the proposed method can also provide references for other prefabricated frames.

Circumferential Expansion Property of Composite Wrapping System for Main Cable Protection of Suspension Bridge

A composite wrapping system for main cable protection of suspension bridges was designed by using prepreg fiber-reinforced composites and nitrile rubber. The circumferential expansion performance of the system was tested, and the curves of circumferential bearing capacity and radial displacement of the components were obtained. Failure modes of each group of components were compared and analyzed. The results show that most of the components are vertically fractured at the lap transition. The increase of the number of prepreg layers contributed the most to the circumferential bearing capacity of components, with a growth rate of 65.31%~109.01%. The increase of rubber belt layers had the most significant effect on the radial displacement of the components, with a growth rate of 7.06%~23.5%. In the initial stage of the test, the strain of each part of the component was smaller due to the compaction by the loading device, and the strain value of the component was generally linearly increased during the loading process, during which the strain of the overlap was the smallest. The calculated cross-sectional temperature deformation of the main cable is in good agreement with the experimental data. The application of the rubber belt increases the deformation of the main cable; therefore, the protection system for the main cable could have more deformation redundancy and delay the arrival of the ultimate strain of the outer prepreg wrap.

Prognosis analysis of strength of H-beams considering corrosion effects

The bearing capacity of components under the influence of corrosion was studied to predict the service life of corroded H-beams. Firstly, based on the experimental data of mechanical properties of corroded steel, the Weibull model was used to fit the test data to obtain corrosion H-beam strength prognosis curve. Then, combined with the target design strength value, the prognosis analysis of the corroded H-beam was carried out. Finally, a numerical example was given to verify the effectiveness of the proposed method. The Weibull model could well fit and predict the bearing capacity of corroded H-beams. According to the bearing capacity attenuation model of H-beams, the service life of the H-beams in our research was well predicted, about 66.5 years. In conclusion, the proposed method can well predict the life of corroded H-beams and it has been verified feasibility and effectively.

Finite Element Analysis on Low Cycle Fatigue Properties of HRBF RC Pile Tip

Numerical simulation of the entire process of HRBF RC pile tip under the low cycle fatigue tests were carried out by nonlinear finite element software ABAQUS. The simulation results included hysteretic curve, skeleton curve, the equivalent plastic strain cloud, the concrete damage cloud and etc. On this basis, it is simulated and calculated by changing the strength of concrete, reinforment ratio, axial load ratio, strength of longitudinal reinforcement and stirrup ratio, to gain the effect of skeleton curve. FEA results show that: the results wear agreed well with the experimental results, and this method was proved feasible; high-strength steel could improve the bearing capacity of components, and its members had good energy dissipation capacity.

Research of the Self-Balanced Cable Support System for Large Cross-Section Cable Tunnel

The cable support system in large cross-section cable tunnel, which can solve the cable laying problem of big cross section cable and multi-loop cable effectively, gradually become the development trend of urban electricity transmission. Combined with the structure feature of large cross section shield tunnel, a new type of self-balanced shield tunnel cable support system is proposed. The safety and rationality of this system has been validated by the structure calculation, the finite element analysis of ADINA and the full scale model test. The analysis shows that the system has some advantages, such as excellent whole mechanical characteristics, strong adaptability, convenient construction and low cost. The system can fully satisfy all requirements of the cable tunnel construction and all functions of operation. The stress distribution of the structure is relatively homogeneous, the bearing capacity of components and the global stability of it also meet the requirements. With the test load which is about 1.5 ~ 4.0 times as large as design load, the support system displacement is 0.65 ~ 2.5 mm, which shows that the structure is safe and reliable. The research achievements can provide theoretical basis and experimental basis for the design of large cross-section cable tunnel.