Theoretical Research And Application Of Bridge With The Spatial Beam Element

Beam structure acts as an important load-bearing structure of a bridge, and consequently, it is necessary for us to carry out in-depth research on beam structure. Therefore, in the present study, beam elements are mainly focuses on, and a in-depth study on related knowledge about beam element theory and secondary exploitation of ANSYS is conducted, which consists of the following aspects.First of all, a 3-node spatial beam element considering its axial tension and bending effects in both directions is constructed in the present study. And interpolation function of higher order is adopted to construct a new type of spatial beam element in local coordinate system. And meanwhile, on the basis of relative theory of finite element, the element stiffness matrix of spatial beam element is derived in detail and its expressions are concluded.Secondly, coordinate transformation matrix of the spatial beam element is derived under the local coordinate system so that it can be applied to global coordinate systems. And moreover, formulas of equivalent nodal loads are deduced, and ways of dealing with common boundary conditions are concluded. What’s more, the new spatial beam element is applied to example analysis, which illustrates that the spatial beam element is computationally feasible.Finally, a secondary exploitation of the finite element software ANSYS is carried out on the basis of above theoretical studies and secondary development tools of UPFs. And by virtue of user-defined unit, the theoretical derivation of the beam element is constructed, and some subroutine are modified, resulting in a new type of element that has the same definition in ANSYS including the same number of nodes, as well as degree of freedom. What’s more, bridge dedicated software Midas Civil combined with examples is adopted to illustrate that the new beam element derived in the present study is feasible in practical analysis.