Residual shear capacity of cold-formed steel-to-sheathing screwed connections at elevated temperatures

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kun Liu ◽  
Wei Chen ◽  
Jihong Ye ◽  
Jian Jiang ◽  
Wenwen Chen ◽  
...  
Keyword(s):  
Shear Strength ◽  
Elevated Temperatures ◽  
Input Parameter ◽  
Single Layer ◽  
Shear Capacity ◽  
Base Layer ◽  
Residual Shear Strength ◽  
Content Type ◽  
Cold Formed Steel ◽  
Fire Conditions

Purpose Most previous thermal-mechanical modeling of cold-formed steel (CFS) walls did not consider the failure of screwed connections under fire conditions because of the limited data of such connections at elevated temperatures. Design/methodology/approach In this study, 285 steady-state tests are conducted on CFS screwed connections with single-layer gypsum plasterboard (GPB) and Bolivian magnesium board (BMB) sheathing at ambient and elevated temperatures. The failure of these connections is described as the breaking of the loaded sheathing edge. Findings For the BMB sheathing screwed connections, hydrochloric acid gas is generated and released above 300°C, and the shear strength becomes much less than that of the GPB sheathing screwed connection above 370°C. Hence, BMB may not be suitable for use as the face-layer sheathing of CFS walls but is still recommended to replace GPB as the base-layer sheathing. The major influencing parameters on the shear strength of screwed connections are identified as the type of sheathing material and the loaded sheathing edge distance. Originality/value Based on the previous and present test results, a unified expression for the residual shear strength of screwed connections with GPB and BMB is proposed at ambient and elevated temperatures with acceptable accuracy. It can be used as the basic input parameter of the numerical simulation of the CFS structures under fire conditions.

Tensile and shear strength for a self-drilling screw and transition of failure-modes and shear-strengths for self-drilling screwed connections at elevated-temperatures

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Fuminobu Ozaki ◽  
Ying Liu ◽  
Kai Ye
Keyword(s):  
Shear Strength ◽  
Test Temperature ◽  
Failure Modes ◽  
Elevated Temperatures ◽  
High Strength ◽  
Shear Loading ◽  
The Self ◽  
Content Type ◽  
Steel Sheets ◽  
Loading Tests

PurposeThe purpose of this study is to clarify both tensile and shear strength for self-drilling screws, which are manufactured from high-strength, martensitic-stainless and austenitic stainless-steel bars, and the load-bearing capacity of single overlapped screwed connections using steel sheets and self-drilling screws at elevated temperatures.Design/methodology/approachTensile/shear loading tests for the self-drilling screw were conducted to obtain basic information on the tensile and shear strengths at elevated temperatures and examine the relationships between both. Shear loading tests for the screwed connections at elevated temperatures were conducted to examine the shear strength and transition of failure modes depending on the test temperature.FindingsThe tensile and shear strengths as well as the reduction factors at the elevated temperature for each steel grade of the self-drilling screw were quantified. Furthermore, either screw shear or sheet bearing failure mode depending on the test temperature was observed for the screwed connection.Originality/valueThe transition of the failure modes for the screwed connection could be explained using the calculation formulae for the shear strengths at elevated temperatures, which were proposed in this study.

Behaviour and resistance of cold-formed steel beams with lipped channel sections under fire conditions

2016 ◽  
Vol 7 (4) ◽  
pp. 365-387 ◽  
Author(s):  
Flávio Arrais ◽  
Nuno Lopes ◽  
Paulo Vila Real
Keyword(s):  
Cross Sections ◽  
Elevated Temperatures ◽  
Numerical Results ◽  
Steel Beams ◽  
Finite Element Program ◽  
Content Type ◽  
Current Design ◽  
Element Program ◽  
Steel Grades ◽  
Cold Formed Steel

Purpose Steel beams composed of cold-formed sections are common in buildings because of their lightness and ability to support large spans. However, the instability phenomena associated to these members are not completely understood in fire situation. Thus, the purpose of this study is to analyse the behaviour of beams composed of cold-formed lipped channel sections at elevated temperatures. Design/methodology/approach A numerical analysis is made, applying the finite element program SAFIR, on the behaviour of simply supported cold formed steel beams at elevated temperatures. A parametric study, considering several cross-sections with different slenderness’s values, steel grades and bending diagrams, is presented. The obtained numerical results are compared with the design bending resistances determined from Eurocode 3 Part 1-2 and its French National Annex (FN Annex). Findings The current design expressions revealed to be too conservative when compared with the obtained numerical results. It was possible to observe that the FN Annex is less conservative than the Annex E, the first having a better agreement with the numerical results. Originality/value Following the previous comparisons, new fire design formulae are tested. This new methodology, which introduces minimum changes in the existing formulae, provides safety and accuracy at the same time when compared to the numerical results, considering the occurrence of local, distortional and lateral torsional buckling phenomena in these members at elevated temperatures.

Cold-formed steel columns at both ambient and fire conditions

2018 ◽  
Vol 9 (3) ◽  
pp. 189-202 ◽  
Author(s):  
Hélder Craveiro ◽  
João Paulo Correia Rodrigues ◽  
Luis Laim
Keyword(s):  
Cross Section ◽  
Critical Temperatures ◽  
Content Type ◽  
Steel Columns ◽  
Channel One ◽  
Steel Members ◽  
Current Design ◽  
Cold Formed Steel ◽  
Support Conditions ◽  
Fire Conditions

Purpose The use of cold-formed steel members has increased significantly in the past few years; however, its design is only briefly addressed in the current design codes, such as the EN 1993-1-3. To evaluate the compressive behavior of single and built-up cold-formed steel members, at ambient and simulated fire conditions with restrained thermal elongation, experimental and numerical tests were undertaken. Design/methodology/approach Four cross-section shapes were tested, namely, one single (lipped channel), one open built-up (I) and two closed built-up (R and 2R), considering two end support conditions, pinned and fixed. Two test set-ups were specifically developed for these tests. Based on the experimental results finite element models were developed and calibrated to allow future parametric studies. Findings This paper showed that increasing the level of restraint to thermal elongation and the initially applied load led to lower critical temperatures. Increasing the level of restraint to thermal elongation, the failure is governed by the generated axial restraining forces, whereas for lower levels of restraint to thermal elongation, the failure is controlled by the temperature increasing. Originality/value This paper is a contribution to the knowledge on the behavior of cold-formed steel columns subjected to fire, especially on the ones with a built-up cross-section, where results on thermal restrained ones are still scarce. It presented a set of experimental and numerical results useful for the development of numerical and analytical analysis concerning the development of new simplified calculation methods.

RIO TINTO ALLOY 242.2

Alloy Digest ◽  
2020 ◽  
Vol 69 (4) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Shear Strength ◽  
Physical Properties ◽  
Elevated Temperatures ◽  
High Strength ◽  
Casting Alloy ◽  
Permanent Mold ◽  
Rio Tinto ◽  
Permanent Mold Castings ◽  
Río Tinto

Abstract Rio Tinto Alloy 242.2 is a heat-treatable, aluminum-copper-magnesium-nickel casting alloy. It is available in the form of ingots to be remelted for the manufacture of sand and permanent mold castings. Alloy 242.0 is used extensively for applications requiring high strength and hardness at elevated temperatures. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and shear strength as well as fatigue. It also includes information on corrosion resistance as well as casting, machining, and joining. Filing Code: Al-463. Producer or source: Rio Tinto Limited.

MST 8Mn

Alloy Digest ◽  
1958 ◽  
Vol 7 (8) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Shear Strength ◽  
High Temperature ◽  
Physical Properties ◽  
Surface Treatment ◽  
Tensile Properties ◽  
Elevated Temperatures ◽  
Heat Treating ◽  
Sheet Alloy ◽  
Temperature Performance

Abstract MST 8Mn is a heat treatable sheet alloy having good formability and recommended for use at moderately elevated temperatures. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive and shear strength as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ti-17. Producer or source: Mallory-Sharon Titanium Corporation.

Experimental assessment of the shear strength of an asymmetric steel composite beam with web openings

2005 ◽  
Vol 32 (2) ◽  
pp. 314-328 ◽  
Author(s):  
Young K Ju ◽  
Do-Hyun Kim ◽  
Sang-Dae Kim
Keyword(s):  
Shear Strength ◽  
Composite Beam ◽  
Residential Buildings ◽  
Shear Capacity ◽  
Structural System ◽  
Web Openings ◽  
Wide Beam ◽  
High Rise ◽  
Beam Shear ◽  
Steel Composite

The number of high-rise buildings has greatly increased in Korea, and storey height is a significant component of tall residential buildings due to the limited city area. To reduce storey height, the wide beam has been adopted in some projects in Seoul such as Trump World, Galleria Palace, and Richencia. The joints between the wide beam and the core wall were too narrow to place the reinforcement, however. This paper investigates a newly developed structural system called the innovative, technical, economical, and convenient hybrid system (iTECH system). The iTECH system has an asymmetric steel assembly with web openings, where the top plate is welded on top of inverted structural "tees" whose cut is referred to as a "honeycomb" type. Both sides of the web and the slab are filled with cast-in-place concrete. The shear capacity was experimentally evaluated and verified, with parameters determined by factors that shared the shear strength of the iTECH beam. The steel web, inner concrete panel, and outer concrete panel contributed to the shear strength of the iTECH beam. The shear stirrup did not contribute much to the shear strength, however, and therefore a design equation using the steel web and inner concrete panel was suggested.Key words: composite beam, shear capacity, monotonic test, high-rise building.

Lubricant compatibility of FKM seals in synthetic oils

2019 ◽  
Vol 72 (5) ◽  
pp. 557-565
Author(s):  
Dilek Bulut ◽  
Tatjana Krups ◽  
Gerhard Poll ◽  
Ulrich Giese
Keyword(s):  
Polyethylene Glycol ◽  
Design Methodology ◽  
Elevated Temperatures ◽  
Failure Mechanisms ◽  
Standard Test ◽  
New Method ◽  
Static Tests ◽  
Content Type ◽  
Lip Seals ◽  
First Results

Purpose Elastomer seals are used in many applications. They are exposed to lubricants and additives at elevated temperatures, as well as mechanical stresses. They can only provide good sealing function when they have resistance to those factors. There are many elastomer-lubricant compatibility tests based on DIN ISO 1817 in industry. However, they are insufficient and costly. Correlations between the tests and the applications are inadequate. The purpose of this study is investigating lubricant compatibility of fluoroelastomers (FKM) seals in polyethylene-glycol (PG)- and polyalphaolefin (PAO)- based synthetic oils and developing a methodology to predict seal service life. Design/methodology/approach A new compatibility test which is more sufficient in terms of time and cost was developed and compared with a standard test, currently used in industry. Compatibility of FKM radial lip seals with PG- and PAO-based synthetic oils with different additives was investigated chemically and dynamically. Failure mechanisms were examined. Findings The new method and the Freudenberg Flender Test FB 73 11 008 showed similar results concerning damages and similar tendencies regarding wear. The additive imidazole derivative was the most critical. Static tests give indications of possible chemically active additives, but alone they are insufficient to simulate the dynamic applications. Originality/value The paper describes a new method to investigate elastomer-lubricant compatibility and gives first results with a variety of lubricants.

Numerical analysis of the shear strength of circular reinforced concrete columns subjected to cyclic lateral loads using linear genetic programming

2020 ◽  
Vol 37 (7) ◽  
pp. 2517-2537
Author(s):  
Mostafa Rezvani Sharif ◽  
Seyed Mohammad Reza Sadri Tabaei Zavareh
Keyword(s):  
Numerical Modeling ◽  
Shear Strength ◽  
Reinforced Concrete ◽  
Numerical Analysis ◽  
Genetic Programming ◽  
Linear Genetic Programming ◽  
Rc Columns ◽  
Content Type ◽  
Alternative Approach ◽  
Engineering Problems

Purpose The shear strength of reinforced concrete (RC) columns under cyclic lateral loading is a crucial concern, particularly, in the seismic design of RC structures. Considering the costly procedure of testing methods for measuring the real value of the shear strength factor and the existence of several parameters impacting the system behavior, numerical modeling techniques have been very much appreciated by engineers and researchers. This study aims to propose a new model for estimation of the shear strength of cyclically loaded circular RC columns through a robust computational intelligence approach, namely, linear genetic programming (LGP). Design/methodology/approach LGP is a data-driven self-adaptive algorithm recently used for classification, pattern recognition and numerical modeling of engineering problems. A reliable database consisting of 64 experimental data is collected for the development of shear strength LGP models here. The obtained models are evaluated from both engineering and accuracy perspectives by means of several indicators and supplementary studies and the optimal model is presented for further purposes. Additionally, the capability of LGP is examined to be used as an alternative approach for the numerical analysis of engineering problems. Findings A new predictive model is proposed for the estimation of the shear strength of cyclically loaded circular RC columns using the LGP approach. To demonstrate the capability of the proposed model, the analysis results are compared to those obtained by some well-known models recommended in the existing literature. The results confirm the potential of the LGP approach for numerical analysis of engineering problems in addition to the fact that the obtained LGP model outperforms existing models in estimation and predictability. Originality/value This paper mainly represents the capability of the LGP approach as a robust alternative approach among existing analytical and numerical methods for modeling and analysis of relevant engineering approximation and estimation problems. The authors are confident that the shear strength model proposed can be used for design and pre-design aims. The authors also declare that they have no conflict of interest.

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