| The increasing span of suspension bridge is a developing trend. The torsion stiffness of the traditional parallel cable suspension bridge is poor. With the increase of the span, the stability of the wind resistance of the suspension bridge becomes very serious. Hyperboloid of one sheet of suspension bridge, with spatial cables, optimizes the cable system, which contributes to the improvement of the static and dynamic characteristics of suspension bridge. Referring to the structural characteristics of the new suspension bridge, a combination of experiment and finite element method is adopted in order to analyze the superiority of the new suspension bridge.The main work and research results are as follows:Test models of hyperboloid of one sheet of suspension bridge and the same scale of parallel cable suspension bridge are built and the static vertical load test, single lane vertical eccentric load test, horizontal static load test and model self-vibration characteristic test are made to study the differences of static and dynamic performances between the two kinds of bridges. The deformation and stress-strain rule of the bridge deck stiffening girder and spatial cables under various working conditions are studied. The fact is proved that the spatial cables possess excellent cooperative working performance. Test results also show that with the same vertical stiffness, the new style of suspension bridge increases the lateral displacement resistance and the torsion resistance greatly. A phenomenon is also found that the greater the vertical load of suspension bridge, the greater the lateral stiffness and torsion stiffness of suspension bridge. The gravity stiffness of suspension bridge is verified by the phenomenon. From the modal test results, The basic self-vibration frequency of the new cable system is larger than that of the traditional parallel cable suspension bridge. This conclusion has also been verified in the finite element calculation.The finite element model of Midas and ANSYS for two kinds of cable suspension bridges are made. The results of finite element analysis and the experimental results are in reasonable range. Using ANSYS the torsion vibration mode and the corresponding frequency are calculated. The results show that new suspension bridge appeared later than parallel cable suspension bridge in torsion vibration type and corresponding frequencies are larger. Modal analysis also found that the new spatial bridges possess more close cable beam connection and more consistent vibration, more eliable constraints of cables. These show that the new type of spatial cable suspension bridge has better wind stability.In this paper, the various plane alignment calculation theories are introduced and plane catenary theories are adapted to the space. Using ANSYS finite element software for hyperboloid space cable suspension bridge to find form in the weight load. Based on ANSYS finite element analysis software, the finite element modles of 4000-meter main span of the two mentioned bridges are built to compare the static performance. Through research, the conclusions are found that hyperboloid of one sheet of suspension bridge with spatial cables possesses better mechanical properties. The finite element calculation and analysis show that the stiffness of the bridge with central buckle can be increased, the cable and the girder are more consistent. Adopting CFRP cables, the stress of the main cable is greatly reduced, which contributes to improving safety reserve. The carbon fiber spatial suspension bridge has a good space stiffness, and the critical wind speed of the static wind and dynamic wind can still meet the design requirements.In summary, the new suspension bridge with spatial cables provides a guide for the construction of large-span bridges. |
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