Cold-Formed Steel Bolted Moment-Resisting Connections with Friction-Slip Mechanism for Seismic Areas

This paper presents investigation on cold-formed steel (CFS) beam-to-column moment-resisting (MR) bolted connections with high energy dissipation capacity suitable for seismic areas. Bolting friction-slip mechanism of the introduced CFS MR connection is developed as its main seismic energy dissipation fuse aiming to postpone or eliminate local buckling and yielding in the CFS MR connections. Finite Element (FE) modelling techniques are employed to effectively simulate the connections with an activated friction-slip mechanism. Hysteretic energy dissipation response of the connections with circular bolting (CB) arrangement designed to slip at 0.5Mp are presented. Based on the obtained FE results, full-scale physical tests on the CB connections have been performed under cyclic loading. Both the FE and the test CB connections comprised double back-to-back segmental-flange beams of 2, 4 and 6mm thicknesses. The results show that the bolting friction-slip mechanism developed for the CB connections can effectively delay local buckling and yielding in the CFS beams of as thin as 2 mm

Semi-rigid floor-to-wall connections using side-framed lightweight steel structures : Concept development

Author statement Alireza Bagheri Sabbagh: Conceptualization, Methodology, Software, Validation, Formal analysis, Investigation, Resources, Writing – original draft, Visualization, Shahabeddin Torabian: Conceptualization, Methodology, Validation, Investigation, Resources, Writing – review & editing, Visualization.Peer reviewedPostprin

Experiments on seismic behaviour of steel sheathed cold-formed steel shear walls cladded by gypsum and fiber cement boards

Acknowledgments The authors are grateful to the Building and Housing Research Center (BHRC) of Iran for providing testing equipment and technical support and Paya Sazeh Pasargad CO, Knauf Iran CO and SHERA CO for providing testing specimens and materials.Peer reviewedPostprin

Rubberised concrete confined with thin-walled steel profiles: a ductile composite for building structures.

Tyre components are high-quality materials, which can be utilised and disposed into construction projects. Despite its high ductility and impact resistance, rubberised concrete (RuC) with high rubber content has a strength much lower than that of conventional concrete. Previous research shows that confinement by a jacket material can significantly improve the strength of RuC. This paper presents how infilling RuC to cold-formed steel (CFS) sections improves strength of RuC and local-buckling-resistance of CFS thin-walled sections, resulting in composite elements where the advantage of each material cancels out the disadvantage of another. In this research, composite RuC-CFS elements are developed and tested with the purpose of using them for structural frames with high energy dissipation capacity under extreme loading conditions, while providing resource-efficiency by using lightweight CFS and recycled RuC materials. To enable infilling of long steel hollow sections for beams and columns, the experimental RuC mixes are designed for self-compaction (SCC). The results reveal that 35% rubber content (by volume) and 3mm thickness of the CFS profile (S275 grade) gives the best performance of the composite by adding 19% to the capacity of the individual constitute materials

Rubberised concrete confined with thin-walled steel profiles : a ductile composite for building structures

Funding Information: This research was supported by the Royal Academy of Engineering Frontiers of Development Seed Funding scheme on Low-carbon seismic-resistant buildings (FoD2021\4\26).Peer reviewedPublisher PD

The Relationship of Knowledge Management and Organizational Performance in Science and Technology Parks of Iran

Any effective and sustainable changes in an organization refers to three areas related with each other and play the best way in the humans, structure and technology fields. The Knowledge management by emphasizing the three areas with the axis of man and preparing him as a knowledge worker tries to achieve organizational goals.Purpose: The current study aims to investigate the existing relationship between knowledge management infrastructures, knowledge management process capabilities, creative organizational learning, and organizational performance.Originality/value: Previous researches did not appraise the effect of knowledge management and its capabilities on organizational performance, and the specific influence of creative organizational learning was disregarded. The present study demonstrates the mechanism of knowledge management effect on organizational performance and describes the comprehensive dimensions of knowledge management performance.Methodology: Statistical population includes executives of Knowledge based companies in Science and Technology Parks of Iran. The 336 questionnaire was distributed to the census, 248questionnaireswerecompletedcorrectly. The research data were analyzed by PLS software. The unit of analysis is a company that has adopted a KMS. Target population of the research consisted of 700 Top Managers of Knowledge based companies in Science and Technology Parks of Iran (N=700). Random sampling method applied in this study and 248Top Managers were considered as the statistical sample based on "Morgan Table". One standard 5-point Likert questionnaire adopted and distributed between Top managers in the park. 252 questionnaires were returned among which 248 ones were statistically investigated. The structural relations among variables were tested using the partial least squares (PLS) method.Findings: This study shows that the KM processes can mediate between creative organizational learning and factors in the KM infrastructure. The results of the study demonstrate that knowledge management process capabilities has the most crucial role in creative organizational learning. The results indicate that there is a significant influence of the infrastructure capabilities (Collaboration, Trust, Learning Culture, Decentralization, Top Management, Promotion, IT support) on the process capabilities, also the impacts of knowledge management process capabilities on creative organizational learning and the impacts of creative organizational learning on organizational performance was confirmed

Novel Cold-formed Steel Elements for Seismic Applications

Novel cold-formed steel (CFS) elements are investigated in this paper for seismic resistant multi-storey moment frames. Premature local buckling and low out-of-plane stiffness are known as the main structural deficiencies of CFS sections with thin-walled elements. These lead to low energy dissipation capacity of the structures made up of CFS sections as the main load bearing members in seismic events. In order to improve the energy dissipation capacity of CFS members, an innovative CFS beam section with curved flanges is developed by numerical FE analysis and experimental work. A web bolted through plate CFS beam-column connection is used to limit out-of-plane actions in transferring the beam forces to column faces. This type of connection, however, produces premature web buckling and needs to be strengthened by a combination of vertical and horizontal out-of-plane stiffeners. Six beam-column connection assemblies including different stiffener configurations were tested. It is shown that the ductility factor and the moment strength are increased by up to ~75% and ~35% respectively relative to the specimen without stiffener. Correspondingly, activation of connection slip leads to a highly stable hysteretic behaviour and a significant increase (up to ~240%) in the hysteretic energy dissipation capacity

Shape optimization of cold-formed steel beam-columns with practical and manufacturing constraints

Peer reviewedPostprin

Experiments on cyclic behaviour of cold-formed steel-rubberised concrete semi-rigid moment-resisting connections.

This paper presents the results of full-scale physical tests on a recently developed cold-formed steel (CFS) semi-rigid moment-resisting connection infilled with rubberised concrete (RuC) for seismic application. The connection comprises side-plates attached to both sides of built-up tubular CFS beam and column sections through either screwed or welded connections. The tests were performed on both bare steel and CFS-RuC composite connections under cyclic loading for comparison purposes. The predominant modes of failure are beam local buckling and side plate plasticity in the bare steel connections and screw shear failure in the composite connections. The results show that the composite connection typically reaches 45% higher strength and 21% greater energy dissipation capacity than the bare steel connection both having 24 screw arrays. These indicate the beneficial effects of the infill RuC in prevention of the beam local buckling in connections with identical connection configuration. The energy dissipation capacity of the bare steel connection having 36 screw arrays, however, was 70% greater than that of the composite connection with 24 screw arrays. This reflects side plate plasticity being a more effective energy dissipation mechanism than the other identified mechanisms

Shrinkage behaviour of SFRC industrial ground floors.

Restrained shrinkage is an important issue in design of concrete industrial ground floors, although it is often overlooked. This paper studies shrinkage behaviour of a SFRC floor subjected to static racking load, through FE simulation. The ultimate load bearing capacity and cracking of the floor is assessed. It is shown that shortly-spaced surface micro-cracks are formed due to shrinkage. These cracks are not initially visible, but get longer and wider after loading. As a result, the load-carrying capacity of the floor reduces significantly, and the equivalent crack opening by up to 10 times