New beam-to-beam joint with concrete embedding for composite bridges Experimental study and finite element modelling

International audienceThis paper deals with a new type of beam-to-beam joint used to connect continuously composite beams in small and medium span bridges. This new joint is realized by encasing totally the two composite beam ends into a massive composite reinforced concrete block. A direct contact between the ends of the bottom flanges of the steel girders over the support ensures the transfer of the compression forces. A half-scale joint specimen has been designed and fabricated. The specimen was first tested at the Structural Laboratory of INSA-Rennes under fatigue loading. Next, the load was monotonically increased up to the specimen failure. The main results of this experimental study are firstly presented. To allow an accurate interpretation of the test results and get a better insight into the joint behaviour, a numerical F.E. model has been developed. The numerical results are presented and compared against experimental ones. Besides, a parametric study has been carried out in order to investigate the influence of key parameters governing the joint behaviour. The influence of the behaviour of this type of joint on the global analysis of a continuous composite beam has then been studied. Finally, a worked example of a two-span continuous railway bridge is presented and effects of intermediate beam-to-beam joint characteristics on the bridge behaviour are discussed

NUMERICAL MODELLING OF COMPOSITE BEAM-TO-BEAM JOINTS-INNOVATIVE SOLUTIONS

International audienceThis paper deals with a numerical F.E. modelling investigation of new joint typology to connect continuously composite beams in bridges. Different types of joint have been selected, designed and tested under fatigue and monotonic loading. For an accurate interpretation of the test results and a better understanding of some specific behaviours (not accessible to measurement) with complex geometries and with the objective to generalize the study, numerical models have been developed using several Finite Element programs including specific programs for composite beams and 3D models based on standard FEM codes. The main numerical results are presented and compared against experimental ones

A simplified 2D model to study the contact–friction at the interfaces of steel–concrete composite beam-to-beam joint

International audienceKeywords: Contact Friction 2D FEM Force transfer mechanism Beam-to-beam joint Steel–concrete composite bridges a b s t r a c t This paper deals with a numerical investigation of the behavior of a new joint typology to connect continuously composite beams in bridges. This beam-to-beam joint consists of butt-plates and headed stud anchors connected to a transverse concrete beam. It has been designed and tested under fatigue and monotonic loading. To describe the joint behavior, a general 3D model is required. However, due to the nonlinearities involved (plasticity, cracking, contact, friction, etc.) the convergence of the iterative process is very difficult to reach with such a model. For an accurate interpretation of the test results and a better understanding of specific local behavior, not accessible to measurement, an equivalent 2D finite element model has been proposed to approach the actual 3D problem. After calibration against experimental data, performances of this 2D model have been illustrated through two studies: the para-metric influence of the butt-plate thickness and the internal force transfer mechanism in the joint