scholarly journals Experimental investigation of typical connections for fabricated cold-formed steel structures

2018 ◽  
Vol 22 (1) ◽  
pp. 141-155
Author(s):  
Weiming Yan ◽  
Tingting Mu ◽  
Zhiqiang Xie ◽  
Cheng Yu
Keyword(s):  
Mechanical Behavior ◽  
Failure Modes ◽  
High Efficiency ◽  
Design Method ◽  
Sheet Thickness ◽  
Steel Structures ◽  
Comparative Investigation ◽  
Lap Shear ◽  
Cold Formed Steel ◽  
European Standards

This article presents a comparative investigation on mechanical behavior and construction characteristics of some typical connections in cold-formed thin-walled steel. The lap shear tests of 96 specimens considering four typical connections with a self-piercing rivet, clinching, self-drilling screw, and blind rivet were conducted. The effects of sheet thickness and thickness ratio on failure modes and mechanical behavior of the four types of connections were investigated. Through analyzing the feasibility of mechanic and construction, the applicability of the four types of connections in fabricated cold-formed steel structures was comprehensively evaluated. The result of the research shows that compared with the other three connections, self-piercing rivet connections are more suitable for modularly fabricated cold-formed steel structures because of its superior mechanical properties, well-formed quality, high efficiency, and potential industrialization. Based on the design methods of fasteners in North American (AISI S100-16) and European standards (prEN1999-1-4) on cold-formed steel structures, an appropriate design method is proposed for self-piercing riveting connections.

scholarly journals Dynamic Behavior of Self-Piercing Riveted and Mechanical Clinched Joints of Dissimilar Materials: An Experimental Comparative Investigation

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Yulong Ge ◽  
Yong Xia
Keyword(s):  
Mechanical Behavior ◽  
Failure Modes ◽  
Dissimilar Materials ◽  
Dynamic Effect ◽  
Comparative Investigation ◽  
Rate Dependent ◽  
Lap Shear ◽  
Baking Process ◽  
Before And After ◽  
Peel Tests

The present work compares the dynamic effect of a self-piercing riveted (SPR) joint with that of a mechanical clinched joint having the dissimilar materials combination. The substrates used in this investigation are aluminum alloy AA5182-O and deep drawing steel DX51D+Z. The static and dynamic behaviors and the failure modes of the SPR and clinching joints are characterized by lap-shear, cross-tension, and coach-peel tests. The influence of the strain-rate-dependent mechanical behavior of the substrates on the joints is examined; this can help improve prediction of the energy absorption of the joints under impact loading. Considering the realistic baking process in a painting shop, the deforming and hardening effects on the SPR and the clinched joints induced by baking are also studied. The specimens are heated to 180°C for 30 min in an oven and then cooled down in air. The SPR and the clinched joints before and after the baking process are compared in terms of the mechanical behavior.

STABILITY BEHAVIOR AND DESIGN OF NONCONVENTIONAL COLD-FORMED STEEL STRUCTURES — RESEARCH REVIEW

2011 ◽  
Vol 11 (05) ◽  
pp. 903-927 ◽  
Author(s):  
LÁSZLÓ DUNAI ◽  
GÁBOR JAKAB
Keyword(s):  
Laboratory Tests ◽  
Method Development ◽  
Failure Modes ◽  
Design Method ◽  
Numerical Models ◽  
Steel Structures ◽  
Product Line ◽  
Research Review ◽  
Cross Sectional ◽  
Cold Formed Steel

In the paper, the methodology and main results of two research projects on nonconventional cold-formed thin-walled steel structures are presented. Laboratory tests, standard-based calculations, numerical models, and the connection of these to design method development are summarized. The implementation of the methodology is presented on two areas in detail: CompressionC-section members and a truss made of C-section members. The studied CompressionC-section members are of various cross-sectional arrangement and end- and lateral-supporting conditions. They consist of single or double asymmetric C-section members; in the latter case, either a back-to-back arrangement is applied or two sections are stuck in each other, forming a box-like closed section. The applied load is in each case compression with different eccentricities. Test arrangement, program, and results are presented; measured load-bearing capacities are compared to resistances calculated according to Eurocode 3, Part 1–3 where applicable, design rules for the cases not covered by the code are proposed. Trusses made of C-sections from the same product line are analyzed in the light of full-scale laboratory tests. EC3-based design formulae are derived for the failure modes obtained in the tests either by modifying existing application rules or by deriving new ones from these. Advanced numerical models of both structures are presented with focus on modeling imperfections, bolted connections, and joint rigidities.

scholarly journals Inelastic Test and Design Method of Cold-formed Steel Lipped Channel Members in Bending

2016 ◽  
Vol 10 (1) ◽  
pp. 625-640
Author(s):  
Xingyou Yao ◽  
Yanli Guo
Keyword(s):  
Finite Element ◽  
Yield Stress ◽  
Failure Modes ◽  
Design Method ◽  
Steel Structures ◽  
Element Model ◽  
Effective Width ◽  
Test Results ◽  
Bending Capacity ◽  
Cold Formed Steel

The aim of this paper is to investigate the inelastic bending capacity and design method of cold-formed steel lipped channel bending members. The bending tests were conducted on 30 cold-formed steel lipped channel members. The nominal yield stress and the nominal thickness of the bending members were 235 MPa and 2mm. The theoretical global buckling stress was higher three times than the yield stress which can make sure the failure of members were in inelastic stage. For each specimen, an analytical analysis using Finite Element Method (FEM) was also conducted considering the influence of the boundary, the ultimate bending capacity, and the failure mode could also be captured. The test results show that the Chinese cold-formed steel specification Technical code of cold-formed thin-walled steel structures (GB50018-2002) is conservative for lipped channel bending sections in inelastic stage. The test results are used to put forward to a revised design method based on effective width method for the current Chinese cold-formed steel specification. The comparison on the bending capacity between the test results and the calculated results by using the proposed method, effective width method and direct strength method in North American cold-formed steel specification (AISI-S120-2016(draft)) shows that the proposed method can consider the inelastic reserve capacity of bending members well. The failure modes and bending capacity of bending members obtained using the idealized shell finite element model, which are close to the experimental results, shows that the idealized model is very well to model the buckling behavior and calculate capacity of bending members.

Effect of stirring time on the mechanical behavior of friction stir spot weld of Al 6061-T6 lap-shear configuration

2018 ◽  
Vol 233 (10) ◽  
pp. 3583-3591 ◽  
Author(s):  
Amirreza Shahani ◽  
Ali Farrahi
Keyword(s):  
Mechanical Behavior ◽  
Failure Modes ◽  
Static Strength ◽  
High Load ◽  
Welding Condition ◽  
Friction Stir ◽  
Al 6061 ◽  
Lap Shear ◽  
Low Load ◽  
Stirring Time

The effect of five different stirring times of friction stir spot welding on lap-shear specimens of Al 6061-T6 alloy has been experimentally analyzed. The welding condition with 2 s of stirring shows the optimum mechanical behavior in comparison to the others. The static strength and fatigue behavior of the joint are justified using the microhardness profiles. The static results prove that the increase of stirring time beyond the 2 s case has little effect on improving the static strength. The fatigue results reveal two different failure modes, which are shear fracture at high load levels and transverse crack growth at low load levels. At medium load levels, although the final failure is similar to high load levels, the transverse growth of the crack outside the welding zone, just like low load levels, is also observed.

Structural Performance of Cold-Formed Steel Structures with Bolted Connections

2005 ◽  
Vol 8 (3) ◽  
pp. 231-245 ◽  
Author(s):  
K. F. Chung
Keyword(s):  
Steel Structures ◽  
Internal Force ◽  
Structural Performance ◽  
Bolted Connections ◽  
Structural Behaviour ◽  
Moment Connections ◽  
Analysis And Design ◽  
Lap Shear ◽  
Numerical Predictions ◽  
Cold Formed Steel

This paper presents a number of experimental and theoretical investigations into the structural behaviour of cold-formed steel structures with bolted connections. Firstly, the basic deformation characteristics of bolted fastenings between cold-formed steel strips in lap shear tests is described, and advanced finite element modelling with solid elements as well as contact elements is carried out for comparison. Secondly, the structural behaviour of lapped Z sections with bolted moment connections is reported, and both analytical and numerical predictions on strength and stiffness of lapped Z sections are presented. Finally, the structural performance of double span lapped Z purlins is investigated numerically where the effects of lapped Z sections over internal supports on the internal force distributions along the purlin members are examined. The description is intended to provide both analysis and design methods as well as understandings to structural engineers, enabling them to design and build cold-formed steel structures rationally with improved structural performance.

Experimental Study on Mechanical Behavior of Serving Prestressed Concrete Poles

2011 ◽  
Vol 368-373 ◽  
pp. 1617-1620 ◽  
Author(s):  
Kai Quan Xia ◽  
Xiang Gang Zhang ◽  
Zong Ping Chen ◽  
Jiang Mei Wang
Keyword(s):  
Mechanical Behavior ◽  
Prestressed Concrete ◽  
Failure Modes ◽  
Ultimate Load ◽  
Design Method ◽  
Limit State ◽  
Safety Performance ◽  
Reinforced Beams ◽  
Loading Tests ◽  
Bending Loading

In order to assess accurately safety performance of prestressed concrete poles servicing 30 years, bending loading tests are carried out on 3 samples extracted randomly, these ones are studied on the mechanical behavior and failure mechanism, failure modes are revealed, and important experimental data including cracking load, the ultimate load of normal use, the ultimate load of carrying capacity is obtained. Furthermore, based on measured test data, the curves of load-crack width and moment-deflection are made among the whole force process. The results show that failure modes of specimens are similar to one of “rare-reinforced beams”. Moreover, based on design method of serviceability limit state, the average security surplus coefficient is 1.2 before collapse damage.

DESIGN OF BOLTED CONNECTIONS SUBJECT TO TORSION AND SHEAR IN THE ULTIMATE LIMIT STRESS STATE

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Mohamed S. Abu-Yosef ◽  
Ezzeldin Y. Sayed-Ahmed ◽  
Emam A. Soliman
Keyword(s):  
Failure Modes ◽  
Focal Point ◽  
Design Method ◽  
Limit State ◽  
Bending Moment ◽  
Steel Structures ◽  
Ultimate Limit State ◽  
Shear Forces ◽  
Limit States ◽  
Ultimate Limit

Steel connections transferring axial and shear forces in addition to bending moment and/or torsional moment are widely used in steel structures. Thus, design of such eccentric connections has become the focal point of any researches. Nonetheless, behavior of eccentric connections subjected to shear forces and torsion in the ultimate limit state is still ambiguous. Most design codes of practice still conservatively use the common elastic analysis for design of the said connections even in the ultimate limit states. Yet, there are some exceptions such as the design method proposed by CAN/CSA-S16-14 which gives tabulated design aid for the ultimate limit state design of these connections based on an empirical equation that is derived for ¾ inch diameter A325 bearing type bolts and A36 steel plates. It was argued that results can also be used with a margin of error for other grade bolts of different sizes and steel of other grades. As such, in this paper, the performance of bolted connection subject to shear and torsion is experimentally investigated. The behavior, failure modes and factors affecting both are scrutinized. Twelve connections subject to shear and torsion with different bolts configurations and diameters are experimentally tested to failure. The accuracy of the currently available design equations proposed is compared to the outcomes of these tests.

Analysis of Mechanical Performance Considering Damage Accumulation of Intersecting Joints in Steel Structures

2011 ◽  
Vol 94-96 ◽  
pp. 583-586
Author(s):  
Bao Feng Fan ◽  
Na Yang ◽  
Qing Shan Yang ◽  
Leroy Gardner
Keyword(s):  
Plastic Deformation ◽  
Mechanical Behavior ◽  
Damage Accumulation ◽  
Failure Modes ◽  
Mechanical Performance ◽  
Local Buckling ◽  
Steel Structures ◽  
Steel Tube ◽  
Geometric Parameters ◽  
Mechanical Behaviors

The mechanical behaviors of intersecting joints considering damage accumulation in steel tube structures is analyzed through the FE-program ABAQUS. The stress characteristic and failure modes of these joints are concluded. Especially, it has been analyzed influence of the change of geometric parameters to mechanical behavior of joints. Finally, the results indicate the joints have a good mechanical performance and good plastic deformation as to excessive local buckling of chord under the loads.

Behaviour of partly stiffened cold-formed steel built-up beams: Experimental investigation and numerical validation

2018 ◽  
Vol 22 (1) ◽  
pp. 172-186 ◽  
Author(s):  
M Adil Dar ◽  
N Subramanian ◽  
A R Dar ◽  
M Anbarasu ◽  
James BP Lim ◽  
...  
Keyword(s):  
Failure Modes ◽  
Numerical Study ◽  
Local Buckling ◽  
Steel Structures ◽  
Vital Role ◽  
Steel Beams ◽  
Design Strength ◽  
Finite Element Software ◽  
Cold Formed Steel ◽  
Reserve Strength

To address the various instability problems in cold-formed steel members, many researchers have mainly focused on developing innovative sectional profiles wherein geometry of the section plays a vital role in enhancing the inherent resistance of such sections against premature buckling. However, the process of forming such innovative shapes is not only complex and time-consuming but sometimes such sections fail to mobilize their complete reserve strength. Hence, a stiffening arrangement of weaker zones for mobilizing the untapped reserve strength is suggested. The contribution of this simple, effective and partly stiffening arrangements, aimed at eliminating/delaying the premature local buckling, is studied both experimentally and numerically and also compared with existing codes. Experimental study was carried out on different simply supported cold-formed steel beams with judiciously proposed stiffening arrangements under four-point loading. An equivalent hot-rolled steel beam was also tested to compare the efficiency of the cold-formed steel beams. The cold-formed steel beams investigated had different width-to-thickness ratio, different geometries and different stiffening arrangements. The test strengths, failure modes, deformed shapes, load versus mid-span displacements and geometric imperfections were measured and reported. The test strengths of the beam models are also compared with the design strength predicted by North American Standards and Eurocode for cold-formed steel structures. To validate the test results further, a numerical study was carried out on such stiffened cold-formed steel beams using finite element software ABAQUS. All these results show that the proposed strengthening system is efficient and economical and allow cold-formed steel beams to reach greater load carrying capacity.

Sign in / Sign up

Export Citation Format

Share Document