Numerical investigation of internal force transfer mechanism in push-out tests

Abstract

International audienceThe case of a push-out test specimen made of prefabricated slabs connected by means of grouped headed studs is investigated in this study. In order to analyse the behaviour of such a shear connection, an experimental study and a numerical analysis have been developed. This paper deals with the presentation of numerical results linked to the parametric study of several layout and loading conditions. The specific 2D nonlinear finite element model developed by two first authors has been presented in a previous paper. This specific finite element model has been developed in order to avoid convergence problems that sometimes occur with the introduction of contact-friction elements in 3D models. In addition, this simplified 2D model allows reducing considerably the time computation when the model concerns the study of a structure at real scale. This 2D nonlinear model is supposed to approach the 3D problem using a ''zone-equivalence'' methodology which we briefly recall the theoretical background. Material nonlinear constitutive laws, 4-noded plane elements and frictional contact finite elements were introduced in the model at the steel concrete interface between the girder flange and the concrete slab and between the studs and the filling concrete. Numerical simulations concerned by this work lead to highlight the internal force transfer mechanisms through the specimen for several layouts and loading conditions, such as the stud arrangements, the filling concrete performance, the reinforcement percentage of the slab, the restrain slab conditions and especially the combination of axial and shear loads. These results could be helpful to have a better interpretation of the push-out test measurements in accordance with the specimen arrangement and the test procedure

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

“…In previous companion papers [15,16] different configurations of push-out tests have been modeled using the 2D proposed model. For each test, comparisons between obtained numerical results and corresponding experimental results have showed a quite negligible contribution of the out-of-plane effects (along the axis perpendicular to the web surface of the steel section of the push-out specimen) showing the ability of the 2D proposed model to simulate correctly the behavior of composite sub-structure.…”

“…According to the results of the numerical calibration undertaken in [15,16] against experimental results of 20 push-out tests, the following values of friction coefficient have been selected; a value of l 1 = 0.3 between the top flanges of the girders and the slab and at the butt-plates/transverse concrete beam interfaces; a value of l 2 = 0.2 between the headed studs and the concrete. A perfect adherence between the rebars and the concrete of the slab has been considered.…”

“…This was done starting from a series of push-out tests carried out previously at the Laboratory and for which a 2D nonlinear finite element model was developed [15,16]. The push-out specimen was reduced to the reference plane of the steel beam web.…”

Shear connection with groups of headed studs

“…The most important studies on shear connections involving groups of headed studs were presented by: Okada et al [1], Shim C.S. [2], Dongyan et al [3], Guezouli et al [4], Chen Xu et al [5]. Out of all these studies, only the experimental research performed by Shim C.S.…”

“…The stress-strain curve defined in Eurocode 2 for concrete C35/45 was used for the part of the stress-strain curve up to the strain of ε cu1 = 3.5. In the strain region ε c >3.5, the stressstrain curve was analytically described using the Chinese code GB50010-2002 [14] with some modifications according to Chang Xu et al [4] and Pavlović et al [13].…”