The Numerical Analysis Of Skew Continuous Grid-structures

In recent years,along with the complete development of the high grade highway and city stereoscopic transportation,the skew bridge has been extensively applicated in the high grade highway,the city road and the stereoscopic transportation hinge for the sake of the line form of the ameliorative road and the increment of the road transportation net1 s ability.Generally,the skew bridge's calculation theories can be divided into three types:The Category 1 is the plank theories method,such as the finite difference method,the finite element method and the finite strip method,etc;The Category 2 is the beam theories,such as the grid beam theories,the general grid theories,the rigid cross-beam method,the elastically-supported continuous beam method and the bar system analytical method,etc;The Category 3 is the practical method,such as the G-M revising method,the grid-beam simple method and Ghali form coefficient method,etc.In this paper,based on analyzing the matrix displacement method and the transfer matrix method,the author combined them to form a new method,which called matrix mixed method,and then used this method to calculate the internal force and displacement of skew bridges. The essence of this method is to transfer the unknown vectors from one end to another,through the matrix's simple multiplication. In the process,we import the displacement method 's concept of replacement ahead,that is to say ,we replace the unknown vectors with new unknown vectors to prevent the delivering and accumulation of errors .At the same time,we completed the skew bridge calculation procedure,and compared the calculation results with the results by the finite element software ANSYS,it proved thecorrectness and practicality of this procedure. In the end,we used this procedure to analyze the influence of the oblique angle to the bearing points and inter-force,and discuss the influence of the ratio (the bending moment to the wrest moment) to the skew bridge. In a word,this paper offers an effective calculation analysis means for the skew bridges.