The Study And Applications Of Mitigating Orthotropic Bridge Deck Welding Deformations

Orthotropic steel bridge panel is widely applied to large-span and mid-span modernbridges. However, welding distortion of the bridge deck panel decreases the assemblyaccuracy, increases the manufacturing cost and influences the use of the bridges. Duringthe assembly processes, much time is taken to rectify and cut. It must influencer progressof the construction and economic effect. So, prediction and control of welding distortionprovides important theoretical significance and engineering practical value.In this paper, finite element method based on the inherent strain is fit for the weldedstructure of the orthotropic steel bridge panel. Under the anti-deformation controlcondition(restraint-weld-rebound), inherent strain of the weld area of the silent stiffenerand the base plate is obtained. And then the obtained inherent strain is applied to thewhole bridge deck panel elements, then residual deformation of the whole panel elementsafter welding distortion control is obtained through elastic finite element method. Thespecific work is as follows:Firstly, three-dimensional dynamic simulation using ANSYS is done for the weldingtemperature field of the silent stiffener and the base plate. Secondly, rules of weldingdeformation is analyzed on the basis of the thermal-elastic-plastic finite element method.In order to get reliable inherent strain, the influence of phase transformation is taken intoaccount. In the same time, welding speed and base plate thickness and some other factorsto influence the welding distortion are analyzed, and the most important factors are weldheat input and size of the base plate. In view of the above, computing method of inherentstrain is discussed and welding inherent strain database of the orthotropic steel bridgepanel is built. In this paper, the practicability of the application of inherent strain methodto the welding distortion control of the orthotropic steel bridge panel is tested. On thebasis of this, inherent strain method is applied to plate element and the control ofdevelopment of welding distortion is discussed, focused on the obtained distortion trend.Specific operation method of anti-deformation control is proposed on the example of areal project. In this paper, rebound after anti-deformation control is taken full consideration andthe anti-deformation is controlled accurately. It offers reliable basis for the production ofthe orthotropic steel bridge panel.