Structural properties of steel-concrete composite joints

Doctoral thesis (2018)

The performance of steel and concrete composite frames is influenced by the structural properties of beam-to-column composite joints. The accurate assessment of these properties constitutes therefore an ... [more ▼]

The performance of steel and concrete composite frames is influenced by the structural properties of beam-to-column composite joints. The accurate assessment of these properties constitutes therefore an important element for a realistic representation of the structural behaviour at serviceability and ultimate limit state. However, the structural joint properties are not equally covered by current design standards; analytical guidance is provided to assess the resistance and stiffness of composite joints, whereas for the rotation capacity an experimental proof is required. Due to the additional effort required to determine the rotation capacity, the global plastic analysis finds little application in the design of composite frames, resulting in a lack of efficiency and material optimization in the final design. In the present work, an analytical model to calculate the rotation capacity of composite joints is derived. Based on the knowledge developed in this research, an improvement of the current design rules for the joint stiffness is proposed. This model is based on an experimental test campaign comprising eight full-scale beamto- column joints with composite slim-floor beams. Besides, a finite element model was developed with the software Abaqus, which has been validated by the experimental tests. Numerical simulations were performed to investigate in-depth the conducted experiments and to analyse the behaviour of additional composite joints with different reinforcement properties. This research has resulted in new analytical design rules for the joint stiffness and rotation capacity. The reliability of these new design rules has been demonstrated for different joint typologies using experimental and numerical data. The development of an analytical method for the rotation capacity of composite joints allows composite beams with composite beam-to-column joints to be designed according to the global plastic analysis without need of experimental evidence. Furthermore, the improvement of the current design rules for the stiffness of composite joints induces a more accurate assessment of the action effects at serviceability and ultimate limit state. This thesis provides therefore a complete methodology to design beam-to-column composite joints. [less ▲]

Design of single-span beams for SLS and ULS using semi-continuous beam-to-column joints. Part 2: Composite beams with variable bending stiffness and joints according to EN 1993-1-8

in Steel Construction (2017), 10(2),

The objective of this article is to facilitate the use of semi-continuous joints by providing ready-to-use tables and charts for design, which also permit the benefits accruing from the use of semi ... [more ▼]

The objective of this article is to facilitate the use of semi-continuous joints by providing ready-to-use tables and charts for design, which also permit the benefits accruing from the use of semi-continuous composite beams to be directly identified. The relevant features for the design of composite beams, such as bending moment distribution, maximum deflection and natural frequency, are derived analytically. The influence of semi-continuous steel joints on the performance of single-span composite beams is analysed. The article concludes with an example of the use of a new slim-floor beam type – the composite slim-floor beam (CoSFB). The tables and charts derived are applied in this example with the intention of demonstrating the advantages of using semi-continuous joints in combination with composite beams. The present article extends the design of semi-continuous steel beams presented in the previous article on this subject. [less ▲]

Influence of Semi-Continuous Composite Joints on the Natural Frequency and Deflection of Composite Beams

in ICASS'2015 International conference series on Advances in Steel Structures & IJSSD 2015 Symposium on Progress in Structural Stability and Dynamics (2015, July)