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.

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.

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. 

Passive System Reliability Modeling of the Combination of Failure Modes

2016 ◽  
Author(s):  
Luciano Burgazzi
Keyword(s):  
Reliability Analysis ◽  
Failure Mode ◽  
System Reliability ◽  
Probabilistic Models ◽  
Failure Modes ◽  
Natural Circulation ◽  
Heat Transfer Process ◽  
Passive System ◽  
Modes Of Failure ◽  
Degradation Failure

Innovative probabilistic models to extend the reliability analysis of passive systems under different modes of failure are proposed. The prevailing failure mode on the system can be predicted through the failure probability assessment on each specific mode. A realistic case is presented to analyze a passive system with two kinds of major failure modes — natural circulation stoppage due to e.g., isolation valve closure (a catastrophic failure) and heat transfer process degradation due to e.g., deposit thickness on component surfaces (a degradation failure). Modeling of each individual failure mode together with system reliability analysis is presented and results are discussed.

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 An Investigation on the Ultimate Strength of Cold-Formed Steel Bolted Connections

2017 ◽  
Vol 7 (4) ◽  
pp. 1826-1832
Author(s):  
N. Konkong
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Ultimate Strength ◽  
Failure Mode ◽  
Failure Modes ◽  
Shear Loading ◽  
Bolted Connections ◽  
Element Analysis ◽  
Bolted Connection ◽  
Cold Formed Steel

This paper presents experimental results and finite element analysis of the cold-formed steel bolted connection under shear loading. Experiments are conducted to study the ultimate behaviors, such as ultimate strength and failure mode of connections. The samples were fabricated into three different groups, single bolted, double bolted and quadruple bolted connection. Material properties were determined by tensile coupon testing. Bearing failure modes were detected in the bolted connection tests. The ultimate capacities were compared with the nominal strengths calculated using the AISI (2012). The comparisons show that the nominal strength parameters predicted by this specification is conservative. The finite element analysis shell elements were used to model the cold-formed steel plate while solid elements were used to model the bolted fastenings for the purpose of studying the structural behavior of bolted connections. Material nonlinearities, contact problem and geometry nonlinearities analysis are carried out in order to predict ultimate strength and failure mode of connections. The results show that the proposed model accurately represents the failure mode and ultimate strength of bolted connection, as determined from experimental investigation. The new factor for type of bearing connection has a good agreement with the tested bearing strength of bolt connection.

Combine Nanoprobing Technique with Difference Analysis to Identify Nonvisual Failures

2006 ◽  
Author(s):  
Cha-Ming Shen ◽  
Tsan-Cheng Chuang ◽  
Jie-Fei Chang ◽  
Jin-Hong Chou
Keyword(s):  
Failure Mode ◽  
Failure Modes ◽  
Electrical Characteristic ◽  
The Novel ◽  
Difference Analysis ◽  
Original Idea ◽  
Deductive Method ◽  
Complete Measurement

Abstract This paper presents a novel deductive methodology, which is accomplished by applying difference analysis to nano-probing technique. In order to prove the novel methodology, the specimens with 90nm process and soft failures were chosen for the experiment. The objective is to overcome the difficulty in detecting non-visual, erratic, and complex failure modes. And the original idea of this deductive method is based on the complete measurement of electrical characteristic by nano-probing and difference analysis. The capability to distinguish erratic and invisible defect was proven, even when the compound and complicated failure mode resulted in a puzzling characteristic.

Case Study and Fault Modeling for Wrong Redundancy Evaluation on DRAM Devices

2007 ◽  
Author(s):  
Martin Versen ◽  
Dorina Diaconescu ◽  
Jerome Touzel
Keyword(s):  
Failure Mode ◽  
Failure Modes ◽  
Fault Modeling ◽  
Mode Analysis ◽  
Root Cause ◽  
Failure Mode Analysis

Abstract The characterization of failure modes of DRAM is often straight forward if array related hard failures with specific addresses for localization are concerned. The paper presents a case study of a bitline oriented failure mode connected to a redundancy evaluation in the DRAM periphery. The failure mode analysis and fault modeling focus both on the root-cause and on the test aspects of the problem.

Methodology for Analysis of Schottky Diode Failures

2010 ◽  
Author(s):  
Bhanu P. Sood ◽  
Michael Pecht ◽  
John Miker ◽  
Tom Wanek
Keyword(s):  
Failure Mode ◽  
Schottky Diode ◽  
Failure Modes ◽  
Schottky Diodes ◽  
Failure Mechanisms ◽  
Forward Voltage ◽  
Fast Switching ◽  
Voltage Drops ◽  
The Common

Abstract Schottky diodes are semiconductor switching devices with low forward voltage drops and very fast switching speeds. This paper provides an overview of the common failure modes in Schottky diodes and corresponding failure mechanisms associated with each failure mode. Results of material level evaluation on diodes and packages as well as manufacturing and assembly processes are analyzed to identify a set of possible failure sites with associated failure modes, mechanisms, and causes. A case study is then presented to illustrate the application of a systematic FMMEA methodology to the analysis of a specific failure in a Schottky diode package.

Failure mode and effect analysis (FMEA) to improve collaborative project-based learning: Case study of a Study and Research Path in mechanical engineering

2021 ◽  
pp. 030641902199904
Author(s):  
Elena Bartolomé ◽  
Paula Benítez
Keyword(s):  
Active Learning ◽  
Failure Mode ◽  
Mechanical Engineering ◽  
Failure Modes ◽  
Collaborative Study ◽  
Project Based Learning ◽  
Educational Process ◽  
Effect Analysis ◽  
Questions And Answers

Failure Mode and Effect Analysis (FMEA) is a powerful quality tool, widely used in industry, for the identification of failure modes, their effects and causes. In this work, we investigated the utility of FMEA in the education field to improve active learning processes. In our case study, the FMEA principles were adapted to assess the risk of failures in a Mechanical Engineering course on “Theory of Machines and Mechanisms” conducted through a project-based, collaborative “Study and Research Path (SRP)” methodology. The SRP is an active learning instruction format which is initiated by a generating question that leads to a sequence of derived questions and answers, and combines moments of study and inquiry. By applying the FMEA, the teaching team was able to identify the most critical failures of the process, and implement corrective actions to improve the SRP in the subsequent year. Thus, our work shows that FMEA represents a simple tool of risk assesment which can serve to identify criticality in educational process, and improve the quality of active learning.

Fuzzy risk assessment for electro-optical target tracker

2016 ◽  
Vol 33 (6) ◽  
pp. 830-851 ◽  
Author(s):  
Soumen Kumar Roy ◽  
A K Sarkar ◽  
Biswajit Mahanty
Keyword(s):  
Failure Mode ◽  
Failure Modes ◽  
Linear Equations ◽  
Mode Analysis ◽  
Failure Behavior ◽  
Membership Functions ◽  
Design And Development ◽  
Effect Analysis ◽  
Content Type ◽  
Criticality Analysis

Purpose – The purpose of this paper is to evolve a guideline for scientists and development engineers to the failure behavior of electro-optical target tracker system (EOTTS) using fuzzy methodology leading to success of short-range homing guided missile (SRHGM) in which this critical subsystems is exploited. Design/methodology/approach – Technology index (TI) and fuzzy failure mode effect analysis (FMEA) are used to build an integrated framework to facilitate the system technology assessment and failure modes. Failure mode analysis is carried out for the system using data gathered from technical experts involved in design and realization of the EOTTS. In order to circumvent the limitations of the traditional failure mode effects and criticality analysis (FMECA), fuzzy FMCEA is adopted for the prioritization of the risks. FMEA parameters – severity, occurrence and detection are fuzzifed with suitable membership functions. These membership functions are used to define failure modes. Open source linear programming solver is used to solve linear equations. Findings – It is found that EOTTS has the highest TI among the major technologies used in the SRHGM. Fuzzy risk priority numbers (FRPN) for all important failure modes of the EOTTS are calculated and the failure modes are ranked to arrive at important monitoring points during design and development of the weapon system. Originality/value – This paper integrates the use of TI, fuzzy logic and experts’ database with FMEA toward assisting the scientists and engineers while conducting failure mode and effect analysis to prioritize failures toward taking corrective measure during the design and development of EOTTS.

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