| The orthotropic steel bridge deck,which is composed of deck plate,longitudinal ribs,and crossbeam,seduces many bridge engineer due to the characteristic it gives,very light.Metallic structures with orthotropic steel deck are particularly suitable where the weight is a crucial parameter of the design,as for large and very large deck or mobile spans.However,the increase in heavy traffic,as the bridge deck is directly loaded by the wheel load and as the results of residual stress due to the welding tend to render the orthotropic decks fatigue behavior an even more critical issue.Therefore,it is vital to study the fatigue crack of orthotropic steel bridge deck deeply.Among these fatigue cracks,the cracks occurred around the ribto-deck(RD)joints,and stringer-to-deck(SD)are most critical because the joint fatigue cracks will cause the top surface to damage.The purpose of this study is investigating the Hot Spot Stress of the SD and RD joints.The main research contents are as follows:(1)The finite element model of orthotropic steel deck structure was constructed by using solid element and shell element and then analyzed.Overall the entire bridge structure this paper investigates two type of welding connections,Stringer-to-Deck(SD)and Rib-to-Deck(RD).These connections are the regions were fatigue is likely to occur.(2)In Total 10 specimens,including 4 SD joints and 6 RD joints,were fabricated for the test.The centric and eccentric load were considered as part of the static loading.It was carried out to measure the stresses near the weld toes and to obtain the hot spot stresses at weld toes by using the extrapolation method.(3)Based on the experimental test results and FEM results,a comparison is made to understand better,and the relationship between both results is studied.The surface stresses of the deck plate are significantly larger than those of the rib near the joint in the 80% weld penetration into the u-rib.The analytical models show good compliance with FE models. |
PDF Full Text Request