Shear behaviour of cold-formed stainless-steel beams with web openings: Numerical studies (original) (raw)
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Shear Capacity of Cold-Formed Stainless Steel Beam with Elliptical Web Openings: Numerical Analyses
2019
Cold-formed stainless-steel sections are increasingly being used in the construction industry, for both architectural and structural applications. The excellent combination of mechan-ical properties and corrosion resistance makes stainless steel a very good material for structural applications. Due to the lack of design rules for stainless steel, the design rules for carbon steel have been generally adopted in the stainless-steel design. However, the prominent non-linear be-haviour of stainless steel, which is the main difference with carbon steel, makes the standards for carbon steel not always accurate in the stainless-steel design. The provision of web openings at appropriate locations in such sections is also important to avoid cutting holes at an inappropriate location during the implementation stage. The type of section and the shape of opening were primarily chosen based on the application. The scope of this study is however limited to stainless steel Lipped Channel Beams (LC...
Finite Element Analyses of Cold-formed Stainless Steel Beam with Web Openings in Shear
ce/papers, 2019
In the recent years, an increase in the use of stainless steel in the construction industry has been witnessed, more specifically in exposed architectural applications and where total life economics, durability, improved resistance to aggressive environment etc. are prime deciding criteria. However, limited research has been undertaken on the shear behaviour and strength of cold-formed stainless steel beam with web openings. Hence a numerical study was undertaken to investigate the shear behaviour and strength of cold-formed stainless steel with web openings. Finite element models of simply supported cold-formed stainless steel Lipped Channel Beams with web openings were developed under a mid-span load. They were then validated with currently available shear test results and further used in a detailed parametric study. In this research, both stocky and slender cross-sections were considered. The ultimate shear capacities from finite element analyses confirmed that currently available design equations are inadequate to determine the shear capacities of stainless steel beams with web openings. Hence improved design equations were developed for the shear capacity of cold-formed stainless steel beams with web openings. This paper presents the details of this numerical study of cold-formed stainless steel beams with web openings, and the results..
Web Crippling Behaviour of Cold-formed Stainless Steel Beams with Non- Circular Web Opening
In recent years cold form stainless steels members are becoming the most popular and widely used structural steel member in the construction industry due to their notable corrosion resistance, recycling option, aesthetically pleasing, and the favourable material properties. However, web crippling behavior and the capacity of unlipped channel sections with non-circular web openings (Square, rectangular and elliptical) has not been investigated sufficiently. Hence, a numerical analyses was undertaken to investigate the web crippling behavior and strength of cold-form stainless steel unlipped channel beams with non-circular web openings. Finite element models of cold-form ferritic stainless steel unlipped channel with offset circular web openings were developed under the interiortwo-flange (ITF) and external-two-flanges (ETF) loading conditions. They were validated with currently available web crippling test results and a detailed parametric study was undertaken to develop an extensive web crippling strength database. Numerical results showed that the currently available reduction factor equations of circular web opening are either conservative or unsafe to use for the non-circular opening. Hence, numerical results were then used to develop a reduction factor to the web crippling capacities of cold-formed stainless steel beams with the solid web.
Numerical Prediction Of Bending Behavior Of Cold-Formed Steel Channels With Web Openings
Aswan University Journal of Sciences and Technology
Cold-formed steel (CFS) sections are popular in structural and architectural applications because of their lightweight properties and high strength. To reduce floor height, different types of openings are added to the web of CFS beams, facilitating the passage of building services through the beams. This study aims to investigate the effectiveness of circular web openings in CFS beams using numerical simulations with finite element analysis (FEA) software (ABAQUS). Nonlinear three-dimensional finite element models (FEMs) for two CFS lipped channels were created and validated against experimental test results to determine failure mode and ultimate load-vertical displacement relationships. The models were then used to predict the bending behavior of CFS beams with circular web openings by varying the diameter and location of holes. The results showed that the load capacity of the beams decreased slightly when the ratio of hole diameter to web height (d w /h w) increased up to 0.5. However, there was a more significant decrease in load capacity when (d w /h w) ranged from 0.5 to 0.7.
Shear Behaviour of Cold-Formed Stainless Steel Lipped Channels with Reduced Support Restraints
2020
Lipped channel beams are commonly used in buildings for load-bearing components such as floor joists and roof purlins. The typical practice is to use one-sided web side plates (WSPs) to attach beams from their webs to the supports at the connections, through bolts. In such realistic conditions, it is not practical to use WSPs over the full height of the webs, thus only a part of the web height is restrained at the supports. This controls the mobilising of diagonal tension field in the web and also provides less restraint to the lateral movement of the web. Therefore, realistic support conditions affect the shear capacity due to the lack of restraint of the web at the supports. On the other hand, the current shear design rules are based on ideal support conditions which do not represent the true scenario. Therefore, it is critical to investigate the effect of reduced support restraints on the shear capacity since it has been given less attention in the literature. This paper presents...
Flexural Behaviour of optimised cold-formed steel beams with sleeve stiffened web openings
2019
CFS beams are often provided with web openings to accommodate building services. However, the area reduction in the web affects their load-bearing capacities. The reduction of bending capacity can be regained through providing suitable stiffeners in the vicinity of the web openings and through providing the web openings to the optimised CFS beams. Many research studies have been conducted for the former but no research studies have been reported for the latter. This paper presents an investigation on providing reinforced web openings to optimised CFS beams to restore the original flexural capacity. A computational analysis was carried out. The Finite Element (FE) elements were validated against experimental data from the literature and then used in conducting detailed parametric studies (80 FE models). The influence of the rectangular openings with four different sizes (hole height-to-web depth ratios: 0.2, 0.4, 0.6 and 0.8) and four different sleeve stiffening lengths (5, 10, 15 an...
Performance Of Steel Beams With Circular Openings Under Static And Dynamic Loadings
IOP Conference Series: Materials Science and Engineering, 2020
In modern structural constructions and high rise buildings, the one of the most important consideration is the efficient design of long span floor composite system and girder beams with web opening. For minimizing the cross sectional of these members, reducing the dead load and cost wise of construction steel beams, web openings are necessary and the floor beams acts compositely with slabs. This study is focused on the performance of floor steel beam with circular web perforation subjected to line loading and on the evaluation of shear buckling capacity for such beams under the effects of static and dynamic loadings. The adopted parameters are web to thickness ratio and web perforation size. Numerical analysis method as finite elements approach by ANSYS software is taken to simulate all models and presented as three dimensional problems. The analysis results indicate that the presence of web perforations reduced the shear strength capacity and increased the deflection, and the configuration of tension field were changed. In case of dynamic loadings, the study showed that the magnitude of deflections is effected by the frequency of the applied external load and varied with respect to the magnitude of the frequency.
STEEL BEAMS WITH WEB OPENINGS STEEL BEAMS WITH WEB OPENINGS 1.0 INTRODUCTION
The responsibility of a Structural Engineer lies in not merely designing the structure based on safety and serviceability considerations but he also has to consider the functional requirements based on the use to which the structure is intended. While designing a power plant structure or a multi-storeyed building, the traditional structural steel framing consists of beams and girders with solid webs. These hinder the provision of pipelines and air conditioning ducts required for satisfactory functioning for which the structure is put up. Very often, the service engineer who is on the scene long after the structural erection has been completed is required to fix air conditioning ducts in place. T h e r e-r o u t i n g o f s e r v i c e s (o r i n c r e a s i n g t h e f l o o r h e i g h t a t t h e d e s i g n s t a g e f o r accommodating them) leads to additional cost and is generally unacceptable. The provision of beams with web openings has become an acceptable engineering practice, and eliminates the probability of a service engineer cutting holes subsequently in inappropriate locations. Beams with web openings can be competitive in such cases, even though other alternatives to solid web beams such as stub girders, trusses etc are available. This form of construction maintains a smaller construction depth with placement of services within the girder depth, at the most appropriate locations. The introduction of an opening in the web of the beam alters the stress distribution within the member and also influences its collapse behaviour. Thus, the efficient design of beams and plate girder sections with web openings has become one of the important considerations in modern structures. In this chapter, methods to evaluate the ultimate shear capacity of the beams and fabricated girders with circular or rectangular web openings are discussed. The methodology is based on the Von Mises yield criterion. 2.0 GUIDELINES FOR WEB OPENINGS AND STIFFENERS The shape of the web openings will depend upon the designer's choice and the purpose of the opening. There are no hard and fast rules to dictate the shapes of the openings. But, for designer's convenience, openings of regular shapes (such as circular or rectangular) are usually chosen. Introduction of openings in the web decreases stiffness of the beams resulting in larger deflections than the corresponding beams with solid webs. The strength of the beams with openings may be governed by the plastic deformations that occur due to both moment and shear at the openings.
2018
The introduction of openings into reinforced concrete (RC) elements leads to reductions in the element’s overall structural capacity and stiffness. These reductions attributed to stresses concentrations and local cracking at the openings region. This paper presents a study aimed at investigating the influence of web openings at shear span of RC beam on its shear behavior. A total of three beams with circular openings and one beam without opening were fabricated and tested. The opening location and size, and shear span-to-depth ratios, were considered as the main parameters. The FE model using ANSYS14.5 software was calibrated with the experimental results to ensure that the simulation process is correct. Furthermore, the specimens were analyzed using ANSYS14.5 with considering the above mentioned parameters. The results showed that the early collapse of the beam occurred when the openings located in a high shear region. Furthermore, by comparing the non-linear FE analysis results wi...
Advances in Structural Engineering
This paper presents a numerical investigation on the web crippling strength of cold-formed stainless steel lipped channel-sections with circular web openings under end-one-flange (EOF) loading condition. In order to take into account the influence of the circular web openings, a parametric study involving 1,992 finite element analyses was performed, covering duplex EN1.4462, austenitic EN1.4404 and ferretic EN1.4003 stainless steel grades; from the results of the parametric study, strength reduction factor equations are proposed. The web crippling strengths predicted by the reduction factor equations are first compared to the strengths calculated using the equations recently proposed for cold-formed carbon steel lipped channel-sections. It is demonstrated that the strength reduction factor equations proposed for cold-formed carbon steel are unconservative for the stainless steel grades by up to 7%. Unified strength reduction factor equations are then proposed that can be applied to all three stainless steel grades.