Finite element modelling of hollow-core concrete slabs

Light weight plastic spheres from recycled plastics have been commonly used in the design and construction of lightweight hollow-core concrete slabs. While this approach is regarded as an effective method to reduce the dead load of slabs and to increase the imposed load carrying capacity, limited technical information exists about the benefits of hollow core concrete slabs and their structural performance. A literature review on the engineering databases uncovered some awards and application articles on the technologies, but little analysis about its structural performance can be found. In this paper, Strand 7 Finite Element Analysis in conjunction with Rhinoceros 4 3D CAD software was used to create composite FEA models of concrete slabs. These composite models were loaded to observe stresses and cracked section behaviour in both hollow-core concrete slabs and solid concrete slabs to determine the relative merits of hollow core concrete slabs over regular solid concrete slabs

Recent contributions on the effect of local damages on the behavior of circular steel hollow sections

Despite many papers on the structural response of thin circular sections, the effect of large imperfections – largely imposed due to damage, collisions, etc. – still leaves many open questions. Over the past few years however, there has been a significant body of tests on steel members with large imperfections, conducted by the authors at the University of Tasmania, with a particular focus on circular hollow sections under different loading conditions. The effect of geometrical irregularities of such structures was examined and subsequently presented in several papers. This paper incorporates these new advances into an organized summary, including key findings of the mentioned experimental data on the effect of local damages on the capacity of different structures with various geometrical features. Discussions are presented on the topic and some general recommendations made in relation to real structures in practice

Behaviour of double-sleeve TubeBolt moment connections in CFT columns under cyclic loading

This research proposes a connection utilising a new blind bolt called TubeBolt to connect I-beams to concrete-filled tubular (CFT) columns. The aim of this study is to resolve the common problems of bolted connections in CFT columns such as column face deformation, bolt elongation, bolt sliding, and low flexural capacity. Tests were carried out on six half-scale specimens exposed to cyclic loading. The experiments were carried out on specimens with TubeBolts or EHB bolts. Different parameters such as hysteretic response, energy dissipation and ductility, failure modes, rotation and stiffness were extensively examined in this paper. Also, the effects of bolt types, bolt grades, and twin stiffener plates were studied on the structural response of the new connections. Test results demonstrated that the connections significantly reduce the above-mentioned problems, exhibit higher energy dissipation and ductility, and lead to a sizable hysteretic loop area. The connection with TubeBolt has higher capacity and stiffness and can avoid severe column face deformations compared to EHB bolts. It was found that using the TubeBolt with a higher bolt grade and twin stiffener plates can prevent brittle failure in the welded zone of the beam-extended endplate. Most importantly, connections with the TubeBolt meet the ductility and seismic design requirements for moment-resisting frames.</p

Experiments and design of concrete-filled steel tubes with timber chips under axial compression

This study includes experimental and analytical sections, which discuss the structural response of concrete-filled steel tubes (CFST). In the experimental section, the authors investigate the CFST columns with different proportions of recycled redwood timber chips embedded inside the concrete. An analytical investigation was also carried out in this paper, which puts together equations proposed by four design codes of Eurocode-4, AISC-LRFD, the Chinese code of DL/T, and ACI to predict the axial capacity. The idea of embedment of timber inside aggregates was inspired due to the significant compression strength of timber compared to concrete. In addition, environmental and sustainability concerns advocate substituting conventional aggregates with recycled natural material. In this study, 18 stub columns (in two groups with different steel tubes) were tested under pure axial compression with various compositions of the aggregates. The failure, capacity, weight, and energy absorption of the specimens were studied to evaluate the effect of the weight reduction as a result of timber embedment into the concrete. The results showed that embedding waste timber inside concrete is promising in upcycling wood residue into a commercially viable product. An equation is developed in this paper that takes into account the effect of confinement based on the assumptions that have been made in the literature. 100 test samples were extracted from the literature with a relatively wide range of geometry and material features, and then the capacity of these columns was calculated by the four standards and the proposed equation in this study. The results of the comparisons were analysed and it was found that the proposed equation predicts the capacity accurately.</p

Numerical Study on Steel Shear Walls with Sinusoidal Corrugated Plates

Abstract Over the past decades a growing demand and interest has stimulated many researchers to investigate different aspects of steel plate shear walls (SPSWs). The structural performance of steel shear walls with sinusoidal corrugated plate infills is investigated in this study. Finite element (FE) analysis was adopted using ANSYS software, wherein flat and corrugatedshear walls - with different thicknesses, various corrugation numbers and angles - were modeled under monotonic and cyclic loads. Results and findings of this study indicate that geometrical variations developed through corrugation can be effective on the capacity, rigidity, and post-yielding responses of such corrugated-web lateral force-resisting systems. In addition, proper design and detailing can result in desirable structural behavior and seismic performance of SPSWs with sinusoidal corrugated infill plates