The Effect Of Welding Residual Stresses On The Cracking Of Orthotropic Steel Bridge Deck

Because of the characteristics of the light weight and high strength,the orthotropic steel bridge deck got rapid development in recent decades.due to its not only to the top of the vehicle under cyclic effects,but also as a part of the main girder structure in stress,it will produce structure local fatigue damage.The thesis introduces the development situation of-orthotropic steel bridge deck and its mechanical properties,discusses the problems and reasons of fatigue cracking.This thesis from the Angle of the bridge panel cracking effect of welding residual stress,the orthotropic steel bridge panel in the engineering of the basis of the actual size,using the finite element software ANSYS to establish 3d entity model of orthotropic steel bridge deck.Adopt the way of life or death unit and heat production rate for the simulation of filling process of molten drops during the process of welding.Due to the complexity of orthotropic steel bridge deck structure,in order to consistent with actual situation as far as possible,the welding,using the orthotropic steel bridge panel the mainstream of the welding process.Using ANSYS transient analysis function to analyze,we can get he welding process and the cooling process of orthotropic steel bridge panel temperature field and stress field distribution.According to this,we can analyze weld temperature field and stress field.Using currently for orthotropic steel bridge deck bridge fatigue cracking research relatively perfect British standard BS5400 for reference,we can get the specified standards fatigue load and details of the structure of the classification and the corresponding stress cycle S-N curve equation.We carry on the static analysis to the model first to identify the prone to fatigue damage of parts.Considering the actual situation of the calculation,We simplify the model and the applied load.After analyzing fatigue life with and without the influence of welding residual stress of the same model,We conclude that the welding residual stress can make a 62.2%reduction of fatigue life.