Moment redistribution in cold-formed steel continuous beams

2013 ◽  
pp. 407-408
Keyword(s):  
Moment Redistribution ◽  
Continuous Beams ◽  
Cold Formed Steel

scholarly journals Moment redistribution in cold-formed steel continuous beams

2016 ◽  
Vol 98 ◽  
pp. 465-477 ◽  
Author(s):  
Chi Hui ◽  
Leroy Gardner ◽  
David A Nethercot
Keyword(s):  
Moment Redistribution ◽  
Continuous Beams ◽  
Cold Formed Steel

scholarly journals Experimental Research of Continuous Concrete Beams with GFRP Reinforcement

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Nikola Baša ◽  
Mladen Ulićević ◽  
Radomir Zejak
Keyword(s):  
Experimental Research ◽  
American Concrete Institute ◽  
Rc Structures ◽  
Moment Redistribution ◽  
Continuous Beams ◽  
Load Carrying ◽  
Current Design ◽  
Frp Reinforcement ◽  
Internal Forces ◽  
Gfrp Reinforcement

Continuous beams are often used within RC structures, which are exposed to aggressive environmental impact. The use of the fiber-reinforced polymer (FRP) reinforcement in these objects and environments has a big significance, taking into account tendency of steel reinforcement to corrode. The main aim of these research studies is to estimate ability of continuous beams with glass FRP (GFRP) reinforcement to redistribute internal forces, as a certain way of ductility and desirable behaviour of RC structures. This paper gives the results of experimental research of seven continuous beams, over two spans of 1850 mm length, cross-section of 150 × 250 mm, that are imposed to concentrated forces in the middle of spans until failure. Six beams were reinforced with different longitudinal GFRP and same transverse GFRP reinforcements, and one steel-reinforced beam was adopted as a control beam. The main varied parameters represent the type of GFRP reinforcement and ratio of longitudinal reinforcement at the midspan and at the middle support, i.e., design moment redistribution. The results of the research have shown that moment redistribution in continuous beams of GFRP reinforcement is possible, without decreasing the load-carrying capacity, compared to elastic analysis. The test results have also been compared to current code provisions, and they have shown that the American Concrete Institute (ACI) 440.1R-15 well predicted the failure load for continuous beams with GFRP reinforcement. On the contrary, current design codes underestimate deflection of continuous beams with GFRP reinforcement, especially for higher load levels. Consequently, a modified model for calculation of deflection is proposed.

Moment redistribution in cold-formed steel sleeved and overlapped two-span purlin systems

2018 ◽  
Vol 21 (16) ◽  
pp. 2534-2552 ◽  
Author(s):  
Pinelopi Kyvelou ◽  
Chi Hui ◽  
Leroy Gardner ◽  
David A Nethercot
Keyword(s):  
Carrying Capacity ◽  
Steel Beams ◽  
Finite Element Models ◽  
Load Carrying Capacity ◽  
Structural Behaviour ◽  
Moment Redistribution ◽  
Load Carrying ◽  
Parametric Studies ◽  
Physical Tests ◽  
Cold Formed Steel

Cold-formed steel purlin systems with overlapped or sleeved connections are alternatives to continuous two-span systems and exhibit different degrees of continuity. Both connection types are highly favourable in practice since they are both strategically placed over an interior support to provide additional moment resistance and rotational capacity where the corresponding demands are at their largest, thus improving the overall structural efficiency. Until recently, full-scale testing has been the most common way of investigating the structural behaviour of such systems. In this study, numerical modelling, capable of capturing the complex contact interactions and instability phenomena, is employed. The developed finite element models are first validated against data from physical tests on cold-formed steel beams featuring sleeved and overlapped connections that have been previously reported in the literature. Following their validation, the models are employed for parametric studies, based on which the structural behaviour of the examined systems is explored, while the applicability of conventional plastic design as well as of a previously proposed design approach is investigated. Finally, the efficiency of these systems in terms of load-carrying capacity is compared with their equivalent continuous two-span systems.

scholarly journals Flexural Behaviour and Internal Forces Redistribution in LWAC Double-Span Beams

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5614
Author(s):  
Ewelina Kołodziejczyk ◽  
Tomasz Waśniewski
Keyword(s):  
Research Study ◽  
Rectangular Cross Section ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Normal Concrete ◽  
Aggregate Concrete ◽  
Moment Redistribution ◽  
Continuous Beams ◽  
Internal Forces ◽  
Reinforcement Interaction

This research study aimed to investigate the effect of the lightweight aggregate concrete and steel reinforcement interaction on the behaviour of continuous beams compared to the normal concrete of the same strength. This paper presents six full-scale, double-span beams with a rectangular cross-section made of both lightweight and normal concrete. The study confirmed that beams made of lightweight aggregate concrete achieve comparable flexural capacities to those made of NWC but their deformability and ductility are lower. Although the redistribution of internal forces depends mainly on the longitudinal reinforcement ratio, the influence of ultimate compressive strains of concrete is also noticeable. The ultimate compressive strains in LWAC are generally lower than in NWC. The lower rotational capacity of LWAC results in smaller degrees of moment redistribution in beams made of this concrete compared to normal concrete beams.

scholarly journals Parametric Study on Moment Redistribution of Fiber Reinforced Concrete Continuous Beams with Basalt FRP Bars

2020 ◽  
Author(s):  
Abdelrahman Hamdi Abushanab ◽  
Wael I Alnahhal
Keyword(s):  
Reinforced Concrete ◽  
Parametric Study ◽  
Steel Reinforcement ◽  
Reinforcement Ratio ◽  
Fiber Reinforced Concrete ◽  
Elastic Behaviour ◽  
Fiber Reinforced ◽  
Moment Redistribution ◽  
Continuous Beams ◽  
Frp Bars

The state of Qatar is suffering from its harsh environment and coastal conditions, which stand for most of the year. As a result, steel-reinforced concrete structures are subjected to rapid corrosion and deterioration. Therefore, there is a necessity to replace the conventional steel reinforcement by fiber-reinforced polymers (FRP) bars. Apart from FRP bars corrosion resistance, their strength to weight ratio is higher than steel reinforcement, which made the FRP, bars a viable alternative to steel reinforcement. Continuous concrete beams are commonly used elements in structures such as parking garages and overpasses. In such structures, forces could be distributed between the critical sections after cracking. This phenomenon is called moment redistribution. It reduces the congested rebars in connections and enhances the ductility of the members. However, the linear-elastic behaviour of FRP materials makes the ability of continuous beams to redistribute loads and moments questionable. This study aims to investigate the capability of moment redistribution of basalt fiber reinforced concrete (BFRC) continuous beams reinforced with basalt FRP (BFRP) bars. Eleven reinforced concrete (RC) continuous beams of 200 x 300 x 4000 mm were tested up to failure under fivepoint loading. The main investigated parameters were the reinforcement ratio (0.6rb, 1.0rb, 1.8rb and 2.8rb; where rb is the balanced reinforcement ratio), stirrups spacing (80 and 120 mm) and volume fractions of Basalt-macro fibers (BMF) (0.75 and 1.5%). A parametric study was then conducted using a validated finite element (FE) model to extend the investigated parameters that may affect the moment redistribution of RC continuous beams. It was concluded that moment redistribution occurs in beams that have at least a ratio of bottom to top reinforcement of 0.3.

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