Failure Modes of Bolted Steel-Wood-Steel Connections Loaded Parallel-to-Grain

2012 ◽  
Vol 256-259 ◽  
pp. 652-656
Author(s):  
Jun Wen Zhou ◽  
Dong Sheng Huang ◽  
Wen Hu Li ◽  
Ai Hua Liu ◽  
Wei Cheng Shi
Keyword(s):  
Brittle Failure ◽  
Failure Modes ◽  
Important Influence ◽  
Row Spacing ◽  
Bolted Connections ◽  
Steel Connections ◽  
Steel Connection ◽  
End Distance ◽  
Bolt Diameter ◽  
Bolt Spacing

Bolted steel-wood-steel connection is an important fashion of connections in timber structure, the manners of failure loaded parallel-to-grain include bearing, row shear-out, group tear-out and splitting, and the brittle failure modes are predominant in some tested results of bolted connections specimens. End distance, bolt spacing, row spacing and the thickness of wood have important influence on the failure modes, and meanwhile, the bolt diameter can not be neglected. Based on the different failure fashion, the equations of strength were given.

On the failure modes and strength of steel-wood-steel bolted timber connections loaded parallel-to-grain

2000 ◽  
Vol 27 (4) ◽  
pp. 761-773 ◽  
Author(s):  
J HP Quenneville ◽  
M Mohammad
Keyword(s):  
Failure Mode ◽  
Failure Modes ◽  
Longitudinal Shear ◽  
Row Spacing ◽  
Specimen Thickness ◽  
Bolted Connections ◽  
Yield Model ◽  
Modes Of Failure ◽  
End Distance ◽  
Bolt Spacing

The current Canadian code provisions for the design of timber bolted connections were essentially developed based on connections showing a ductile behavior and then further modified to account for situations where connections fail in a brittle way. An experimental study was undertaken to evaluate the strength of bolted connections specifically experiencing a brittle mode of failure. Specimens consisting of steel-wood-steel connections with either 19.1 mm or 12.7 mm bolts were tested in tension. Test variables included end distance, bolt spacing, row spacing, number of bolts per row, number of rows, thickness and species of wood member, glulam or sawn lumber members. Connections were tested to the ultimate to observe possible modes of failure as variables were changed. Results show that the current Canadian standard approach to evaluate the resistance of timber bolted connections is not optimal although conservative. Brittle modes of failure such as row shear-out, group tear-out, and splitting were observed. The resistances calculated using the O86.1 design provisions are as little as a third as compared to tested results. Also, the design equations do not allow the designer to take advantage of the increases in strength as a result of increases in row spacing, as observed in tests. Analysis of the results show that the longitudinal shear stress at failure is related to a parameter which is a function of the smaller distance (end distance or bolt spacing) and the specimen thickness. This relation was used to formulate design equations to predict the row shear-out and group tear-out strengths of glulam specimens using the specified strength values listed in O86.1. As well, it was found that Mode I of the European yield model is the only ductile ultimate failure mode and that other equations for bearing failure can be neglected. In this paper, the research program is described, results are presented, and an alternate design approach is proposed to predict the failure mode and the ultimate strength of steel-wood-steel bolted connection groups.Key words: bolt, connection, strength, failure, design, code, ductile, brittle.

An Experimental Study on Ultimate Behaviors of Double Shear Bolted Connections with Ferritic Stainless Steel

2013 ◽  
Vol 664 ◽  
pp. 976-979
Author(s):  
Tae Soo Kim ◽  
Min Seung Kim
Keyword(s):  
Stainless Steel ◽  
Ferritic Stainless Steel ◽  
Test Results ◽  
Bolted Connections ◽  
Bolted Connection ◽  
Double Shear ◽  
Loading Direction ◽  
Constant Dimension ◽  
End Distance ◽  
Bolt Diameter

Based on the existing test results of single shear bolted connection fabricated with cold-formed ferritic stainless steel, in this study, the experiment for double shear bolted connections with bolt arrangements(1×2, 2×2) and end distance parallel to the loading direction as main variables has been performed. Specimens were planed with a constant dimension of edge distance perpendicular to the loading direction, bolt diameter, pitch and gauge. Ultimate strength and fracture mode obtained from test results were compared with those predicted by current American and Japan design codes such as AISI and AIJ.

scholarly journals Experimental investigation of two-bolt connections for high strength steel members

2018 ◽  
Author(s):  
Yan-Bo Wang ◽  
Yi-Fan Lyu ◽  
Guo-Qiang Li
Keyword(s):  
Failure Mode ◽  
Failure Modes ◽  
High Strength Steels ◽  
High Strength ◽  
Double Shear ◽  
Loading Direction ◽  
Steel Members ◽  
Edge Distance ◽  
End Distance ◽  
Bolt Spacing

This paper presents an experimental research on bearing-type bolted connections consisting of two bolts positioned perpendicular to the loading direction. A total of 24 connections in double shear fabricated from high strength steels with yield stresses of 677MPa and 825MPa are tested. Two failure modes as tearout failure and splitting failure are observed in experiments. The effect of end distance, edge distance, bolt spacing and steel grade on the failure mode and bearing behavior are discussed. For connection design with bolts positioned perpendicular to loading direction, it is further found that combination of edge distance and bolt spacing effectively determines the failure mode and ultimate load. The test results are compared with Eurocode3. An optimal combination of edge distance and bolt spacing as well as related design suggestion is thus recommended. 

The Study on Mechanical Properties of Single-Bolted Steel-Glulam-Steel Joints

2011 ◽  
Vol 255-260 ◽  
pp. 204-208 ◽  
Author(s):  
De Liang Xu ◽  
Wei Qing Liu ◽  
Ding Zhou ◽  
Jian Dong Ding ◽  
Ying Lei ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bearing Capacity ◽  
Failure Mechanism ◽  
Failure Mode ◽  
Mechanical Performance ◽  
Timber Structures ◽  
Bolted Connections ◽  
Steel Connections ◽  
Steel Connection ◽  
Steel Joints

Seven groups, total of 31 single-bolted steel-glulam-steel joints, were tested for their mechanical performance. The mechanical properties of single-bolted steel-glulam-steel connection subjected to a load parallel to the grain have been studied. The failure mode and failure mechanism of bolted connections were discussed in detail. It is shown that the failure mode, bearing capacity, stiffness and ductility of the joint are mainly relative to the thickness of the glulam and the diameter of the bolt. Due to the wide application of bolted steel-glulam-steel connections in engineering, the present work can be taken as a reference in manufacture, and design of modern timber structures.

DOUBLE SHEAR TEST BEHAVIOUR OF BALAU SPECIES FOR DIFFERENT END DISTANCE

2016 ◽  
Vol 78 (5-4) ◽  
Author(s):  
Nor Jihan Abd Malek ◽  
Rohana Hassan ◽  
Elamin Mohamed Ali ◽  
Mohd Nizam Shakimon
Keyword(s):  
Shear Test ◽  
Failure Modes ◽  
Failure Behavior ◽  
Timber Species ◽  
Yield Model ◽  
Timber Joint ◽  
Double Shear ◽  
End Distance ◽  
Double Shear Test ◽  
Bolt Diameter

Timber connection is the most important part in timber structural building. In design, it depends on parameter criteria such as bolt diameter, bolt spacing, edge and end distance. End distance is one of design criteria that will influence mechanical timber joint such in single and double shear. This study focuses for a single fastener joint loaded in double shear with 12mm and 16mm bolt diameters having 30mm and 40mm end distance respectively. Double shear test was conducted on Balau timber species and the finding also focuses on the pattern failure modes with reference to European Yield Model (EYM) theory according to National Design Specification (NDS) 2005. It shows that the joint ability to withstand load decreased when the bolt diameter and end distance smaller and conversely with larger bolt diameter. The failure behavior for 12mm diameter tends to fail into category IIIs which described two plastic hinges formed with crushing of wood fibres in the side members. While, 16mm diameter bolt tends to fail under categories of mode Is which dowel bearing failure or crushing of the side members. Eventually, 12mm bolt diameter produces lower shear strength compared to 16mm bolt diameter. 

scholarly journals NUMERICAL ANALYSIS OF A DOUBLE SHEAR STANDARD BOLTED CONNECTION CONSIDERING MONOTONIC LOADINGS

2017 ◽  
Vol 9 (4) ◽  
pp. 183-194 ◽  
Author(s):  
Mariana Ferreira RODRIGUES ◽  
José CORREIA ◽  
Bruno PEDROSA ◽  
Abílio DE JESUS ◽  
Bruno CARVALHO ◽  
...  
Keyword(s):  
Numerical Models ◽  
Bolted Connections ◽  
Bolted Connection ◽  
Double Shear ◽  
Steel Connections ◽  
Research Activities ◽  
Linear Behaviour ◽  
Speed Up ◽  
Monotonic Loads ◽  
Globalized World

The behaviour of standard bolted steel connections submitted to monotonic loads, through the use of numerical models, is presented in the current paper. The bolted connections allow speed up constructive processes in an increasingly competitive and globalized world in which the costs are a decisive factor in the development of a project. The use of computational tools in the analysis of bolted connections becomes determinant, mainly for new solutions or solutions less explored in terms of design codes. Throughout the years, bolted connections have been suffering transformations resulting from research activities performed by many authors. Rivets have been replaced by bolts, the main achievement being the pre-stressed bolts. Methodologies based on finite element analyses were proposed for double shear bolted connection. The non-linear behaviour of these connections is investigated and their performances are compared. In the numerical modelling of the bolted connection, linear elastic and elastoplastic analyzes reveal that there are two slip levels associated with local non-linearities caused by the contact pairs, which vary with clamping stresses.

scholarly journals Evaluation of Seismic Demand for Substandard Reinforced Concrete Structures

2018 ◽  
Vol 12 (1) ◽  
pp. 9-33
Author(s):  
Nicholas Kyriakides ◽  
Ahmad Sohaib ◽  
Kypros Pilakoutas ◽  
Kyriakos Neocleous ◽  
Christis Chrysostomou ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Seismic Performance ◽  
Performance Prediction ◽  
Brittle Failure ◽  
Failure Modes ◽  
Shaking Table ◽  
Equivalent Linearization ◽  
Diagram Method ◽  
Capacity Curves ◽  
Non Linear

Background: Reinforced Concrete (RC) buildings with no seismic design exhibit degrading behaviour under severe seismic loading due to non-ductile brittle failure modes. The seismic performance of such substandard structures can be predicted using existing capacity demand diagram methods through the idealization of the non-linear capacity curve of the degrading system, and its comparison with a reduced earthquake demand spectrum. Objective: Modern non-linear static methods for derivation of capacity curves incorporate idealization assumptions that are too simplistic and do not apply for sub-standard buildings. The conventional idealisation procedures cannot maintain the true strength degradation behaviour of such structures in the post-peak part, and thus may lead to significant errors in seismic performance prediction especially in the cases of brittle failure modes dominating the response. Method: In order to increase the accuracy of the prediction, an alternative idealisation procedure using equivalent elastic perfectly plastic systems is proposed herein that can be used in conjunction with any capacity demand diagram method. Results: Moreover, the performance of this improved equivalent linearization procedure in predicting the response of an RC frame is assessed herein. Conclusion: This improved idealization procedure has been proven to reduce the error in the seismic performance prediction as compared to seismic shaking table test results [1] and will be further investigated probabilistically herein.

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