Advanced Materials Research Vols. 194-196

Abstract: Rigid frame bridge is widely used in China because of its lower cost. The aseismatic ability of rigid frame bridge is difficult to judge for designer when the bridge is used to span valley in intensity region. The seismic response of one rigid frame bridge with 160m span is calculated. It is indicated that the aseismatic ability of rigid frame bridge is good and bridge design is controlled by bending moment at bottom of pier.

Abstract: Collisions between over-high trucks and protection frame for height limit happen frequently, which seriously destroyed the railway infrastructure and affected the road traffic safety. Based on nonlinear software ANSYS/LS-DYNA, the collision process of over-high trucks and protection frame is simulated, and the failure mechanism of protection frame is analyzed respectively from deformation, stress, load etc. Load analysis results indicate that the maximum impact force is approximately direct proportional to the initial velocity, which can be used for choosing the collision load in the design. Stress analysis results indicate that the maximum stress usually occurs in the protection frame crossbar and joint area. Adding the diagonal bracing or increasing the crossbar thickness are the effective methods to improve the impact resistance capability of the protection frame.

Abstract: Based on the reasonable selection and use of frame system and frame- supporting system in steel structure housing in multi-story or high-rise steel structure housing, frame system and frame- supporting system are being made mode analysis, calculated and contrastive analyzed by means of the three dimensional analysis software (ETABS) in this paper. Some quantitative evaluation standards are obtained for two steel structure systems and it provides some references for practical engineering.

Abstract: The modal analysis and harmonic response analysis of the machine tool table with periodic truss-core structures are analyzed and calculated by finite element analysis software-ANSYS Workbench, then we get the finite element analysis results. After comparing the results with finite element analysis results of the original machine tool table, we come to the conclusion that the dynamic properties of the machine tool table with periodic truss-core structures are better than the original machine tool table’s. It makes a base for optimized design and remanufacturing.

Abstract: According to the characteristics of cooler, the finite element model of air cooler is established using ANSYS f software. The force and moment are acted on nozzles using MPC184 element. The first natural frequency is given. Then the stresses of cooler under normal operating load case and under accidental load case are calculated respectively. The stresses of nozzles and foot were checked according to RCC-M specification and meet the requirements.

Abstract: In order to develop an effective seismic shear strengthening method for improving the earthquake behavior of existing R/C short columns, experimental studies are conducted by using four beam-column sub assemblage specimens with a short column. Three short columns of these specimens are strengthening by steel plates and concrete, while other one is without any steel plate strengthening. All the specimens are tested under a constant gravity load and alternately repeated lateral forces. Test results demonstrate that, if the short column is strengthened by a welded square tube and concrete, then brittle shear failure does not occur and the column can develop its ultimate flexural moment capacity. It is also shown by tests that the proposed strengthening method using steel plates and concrete is applicable to repair and rehabilitate the damaged short columns failed in the brittle shear mode.

Abstract: Top 10 natural frequencies and mode shape characteristics of four types of light-rail box girder bridges were summarized by FE modeling. And the mode analysis results were horizontal, vertical contrasted. Furthermore, the relationships between the natural frequency and structural stiffness were studied. Finally, the bridge-types of four types of light-rail box girder bridges were optimized. The results show that the torsional stiffness of the box girder with side walls and diaphragms is much greater than that of the box girder without side walls and diaphragms, the torsional stiffness of the single-box-double-cell box girder with eccentric-hole diaphragms is greater than that of the single-box-double-cell box girder with center-hole diaphragms, and the single-box –double-cell box girder with side walls and eccentric-hole diaphragms is the optimal bridge type of all light-rail box girders.

Abstract: The magneto rheological damper (MRD) is employed to control the seismic response of large-scale aqueduct. The active control, semi-active control and passive control strategies are systematically compared, The results indicated that the magneto rheological dampers are effective in reducing the aqueduct response, the mitigation rate of semi-active control approaches with the active method The results from the present study may serve as a reference base for seismic design of large-scale aqueducts, and provide theoretical basis of aqueduct using semi-active devices.

Abstract: The horizontal stiffness of steel frame is relatively weak. So designers introduce brace system into steel frame to increase the horizontal stiffness. In order to guarantee the safety of the structure, we should imitate the performance of the structure under seismic loads. In this paper, the pseudo-dynamic test was conducted on the semi-rigid connection of steel frame and the semi-rigid connection of steel-braced frame. The test results show that the brace can increase the ductility of the structure, decrease the displacement of the top floor, decrease the interlayer displacement, and bear ground floor shearing-force. So the brace greatly impacts the performance of the structure. It has the ability of anti-earthquake and strong resistance ability of lateral force.

Abstract: Continuous beam bridge was widely used, while seismic problem of it was prominent in meizoseismal area. According to seismic-isolation principle and mechanism of PSD, seismic performance of PSD were studied and the parameters of PSD were analyzed later, based on south approach of North Branch of Xia-Zhang Sea-Crossing Bridge. It was found that PSD, a combination of preloaded spring and liquid viscous damper, was an effective seismic-isolation device which could significantly reduce the seismic response of continuous beam bridge in longitudinal and transverse direction. Damper coefficient was the main parameter of PSD, while preloaded force, linear spring stiffness and damper index had a little effect on seismic performance of PSD.