Van Bentum Prijs: Olga Bushunova (Technische Universiteit Delft & FMAX-ISAAC) - The behaviour of composite deep deck ComFlor210 under concentrated load

The research concentrated on studying a behavior of the deep composite deck ComFlor210 under a concentrated force placed on a rib at different locations. The research is essential because the procedure to establish the effective width, over which the concentrated force is distributed, in a case of the deep composite deck is out the scope of Eurocode 4. In Eurocode 4 the procedure to calculate the effective width is applicable for slabs with narrowly spaced webs only. Meanwhile the composite construction prevails in the non-residential multi-story sector due to the labor and material efficiency it combines together with good structural performance. The distribution of a concentrated force in a composite slab ComFlor210 was studied numerically with FEA (Abaqus) and parametric script (Python) and analytically using classical beam theory.

The finite element analysis of the composite slab in Abaqus/CAE was performed using the material properties and geometry of a tested specimen at TU Delft – composite slab ComFlor210 with one reinforcement in the top deck. In order to conduct a parametric study on a composite slab with varying load positions and geometry properties, the finite element model included the entire slab length and all reinforcement present in a slab in reality. The created finite element model was verified by making a comparison with results of a conducted test at TU Delft performed by M. Dracht. The finite element model of a composite slab with 5.4m span and one reinforcement mesh in the top deck showed good agreement with test results in the elastic stage (see load-deflection curve of middle rib 3).

The parametric study of composite slab ComFlor210 loaded with concentrated force 60kN revealed that in a slab with spans 3.2m and 5.4m the load was distributed over three middle ribs, as the contribution of two outer ribs was less than 10%. However, in a slab with 7.2m span, the load was spread over all five ribs (contribution of two external ribs accounted for 20%). The parametric study on a composite slab ComFlor210 loaded with concentrated force 145kN showed that with increasing the area of rib reinforcement and the thickness of steel sheeting the composite slab displays stiffer behavior in the plastic zone of the load-deflection curve. For the elastic part of the load-deflection curve, the variation in cross- sectional parameters causes a minor change in a slab response, meaning that concrete properties and overall slab geometry are decisive in this stage.

The proposed engineering model was unable to predict the deflection of the composite slab under concentrated load in a loading range 10-40kN with the desired accuracy. The assumptions that the modulus of elasticity of cracked concrete equals one-third of not cracked material, probably, lead to an underestimation of rib bending stiffness at low load level.

Het afstudeerrapport is te downloaden van de website van de TU Delft.

Het oordeel van de jury:
Deze prijs is specifiek bedoeld voor innovatieve toepassingen van (dunne) staalplaat. De jury heeft de prijs toegekend aan deze studie naar de ComFlor 210 staalplaatvloer omdat deze bijdraagt aan de ontwikkeling van kennis over de krachtswerking in dunne staalplaat ‘IJverig onderzoekswerk’, ‘Indrukwekkend robbertje mechanica’ ‘Nuttige bijdrage aan de praktijk’, kortom Van-Bentumprijswaardig!

Meer informatie over de Van Bentum prijs is te vinden op deze pagina.