摘要: The H-type welding frame of passenger car bogie was simplified to the model composed of straight girders with uniform sections, the measures to reduce the distortion stiffness of the bogie frame was researched by observing the deformation distributions of different girders under distortion load, and verified by using FEM. It is pointed that the distortion stiffness of the frame can be reduced by 3% when slotting on the cover plate of side sill, when changing the section of transom, the stiffness can be reduced by 19%, and the maximum von_Mises stress under over load can be reduced by 3%. The result indicates that there is less influence on the stiffness when slotting on the cover plate of side sill, but it will cause strong stress concentration in local areas. The bending and distortion stiffnesses of transom should affect the distortion stiffness of the frame strongly. Changing circular section to box section can reduce the distortion stiffness of the frame obviously. The maximum von_Mises stress of the frame under over load situation is lower because of the reduction of the distortion stiffness. The influence of track warping load on the strength of the frame has abated.更多>
摘要: In order to improve the road performances of base course made of large stone porous asphalt mixture(LSPM), MAC(multigrade asphalt cement) modified asphalt was used in LSPM, the performances of matrix aphalt, MAC modified asphalt and SBS modified asphalt were compared, the material composition design, construction technology and the road performances of MAC modified LSPM, such as high-temperature stability, anti-fatigue property, permeability and anti-reflective crack property, were studied, and test roads were constructed. Test result shows that the porosity of LSPM is between 13% and 18%, its asphalt membrane is thicker than 12 μm, its modulous is between 400 and 600 MPa, the rut depth of test road opening to traffic for two years is between 4 and 8 mm. Obviously, MAC modified LSPM has better road performances. 4 tabs, 2 figs, 16 refs.更多>