P. Pivonka, R. Lackner, H.A. Mang:
"Numerical Investigations of Headed Studs with Inclined Shoulders";
in: "RILEM International Symposium Connections between Steel and Concrete", R. Eligehausen (ed.); RILEM, Cachan, 2001, 729 - 746.
Failure of steel-concrete connections such as anchor bolts strongly depends on the material behavior of steel and concrete, respectively, and the geometric properties. The latter are commonly represented by the so-called span/depth-ratio (a/d-ratio). Hereby, the embedment depth "d" is equal to the distance from the anchor head to the concrete surface. The span "a" represents the distance from the center of the steel rod to the support.The aim of the investigation presented in this paper is to obtain clear insight into the structural behavior of headed studs with inclined shoulder. For this purpose, two constitutive models for concrete formulated in the framework of plasticity theory are considered in the numerical simulations. The first model is a multi-surface model consisting of one Drucker-Prager surface reformulated for the description of confined compressive stress states, and three Rankine surfaces for the description of the tensile material behavior of concrete. The second model is a single-surface model considering the dependence of the concrete strength on the Lode angle. Both models account for the influence of confinement on the ductile behavior of concrete.
In the numerical analyses, headed studs characterized by different geometric properties, i.e., by different a/d-ratios will be considered. Moreover, the influence of the finite element (FE) mesh and the material model on the peak load and the failure mode will be investigated.
Keywords: concrete, Extended Leon Model, anchor bolt, headed stud, multi-surface model, shear failure