Laboratory tests of ice interaction with steel booms

1996 ◽  
Vol 23 (2) ◽  
pp. 560-566 ◽  
Author(s):  
G. W. Timco ◽  
A. M. Cornett
Keyword(s):  
Failure Mode ◽  
Laboratory Tests ◽  
Failure Modes ◽  
Quantitative Information ◽  
Ice Thickness ◽  
Test Program ◽  
Buckling Failure ◽  
River Loads ◽  
St Lawrence River ◽  
Ice Control

A test program was carried out to study the interaction of ice with sections of ice-control booms. Two different boom shapes and four different boom sizes were tested. The results indicate that there can be several different failure modes for the ice during the interaction. Particularly high loads were obtained when the ice failed in a buckling failure mode. To minimize the ice-induced loads, the boom must be designed to prevent this failure mode and induce flexural failures in the ice. This note presents quantitative information on the loads measured for different boom shapes and sizes, and for different ice thickness. The results can be used to help optimize the design of a suitable boom for ice control. Key words: ice, ice control, ice booms, St. Lawrence River, loads, forces, design.

Buckling analyses of double-shell octagonal lattice truss composite structures

2017 ◽  
Vol 52 (9) ◽  
pp. 1227-1237 ◽  
Author(s):  
Qianqian Sui ◽  
Changliang Lai ◽  
Hualin Fan
Keyword(s):  
Failure Mode ◽  
Composite Structures ◽  
Failure Modes ◽  
Local Buckling ◽  
Buckling Mode ◽  
One Dimensional ◽  
Load Carrying ◽  
Global Buckling ◽  
Buckling Failure ◽  
Equivalent Continuum

To reveal the compression failure modes of one-dimensional hierarchical double-shell octagonal lattice truss composite structures (DLTCSs), finite element modeling and equivalent continuum models were developed. DLTCS has three typical failure modes: (a) fracture of the strut, (b) global buckling, and (c) local buckling. Failure mode maps were constructed. It is found that column of long enough length will collapse at global buckling. When the column length decreases, the failure mode will turn to local buckling and strut fracture successively. Bay length greatly influences the buckling mode. Longer bay length could change the buckling mode from global buckling to local buckling. Compared with single-shell lattice truss composite structure, DLTCS has advantage in load carrying when the column fails at strut fracture or global buckling, while local buckling tolerance of DLTCS is smaller.

scholarly journals Comparative Investigation on the Failure Modes of Natural Kenaf/Epoxy Reinforced Composite Hexagonal Tubes

2016 ◽  
Vol 709 ◽  
pp. 7-10 ◽  
Author(s):  
M.F.M. Alkbir ◽  
S.M. Sapuan ◽  
A.A. Nuraini ◽  
Mohamad Ridzwan Ishak
Keyword(s):  
Failure Mode ◽  
Transverse Crack ◽  
Failure Modes ◽  
Epoxy Composite ◽  
Local Buckling ◽  
Comparative Investigation ◽  
Composite Tubes ◽  
Reinforced Composite ◽  
Buckling Failure ◽  
Mode Response

This study aims to investigate failure mode response of woven natural kenaf/epoxy composite hexagonal tubes subjected to an axial and lateral quasi-static crushing test. The hexagonal composite tubes were prepared by the hand lay-up technique using a variety of hexagonal angles 40ο, 50 ο, and 60 ο. The result showed that hexagonal composite tubes under an axial compression test exhibited few failure modes such as, the transverse crack failure mode . Splaying failure mode and local buckling failure mode respectively, whereas the tubes under lateral test only exhibited longitudinal fracture.

The Effect of Fiber Content on the Crashworthiness Parameters of Natural Kenaf Fiber-Reinforced Hexagonal Composite Tubes

2016 ◽  
Vol 11 (1) ◽  
pp. 155892501601100
Author(s):  
M. F. M. Alkbir ◽  
S. M. Sapuan ◽  
A. A. Nuraini ◽  
M. R. Ishak
Keyword(s):  
Failure Mode ◽  
Transverse Crack ◽  
Failure Modes ◽  
Progressive Failure ◽  
Fiber Content ◽  
Fiber Reinforced ◽  
Kenaf Fiber ◽  
Buckling Failure ◽  
The Mean ◽  
Woven Kenaf

The aim of this paper is to study the effect of fiber content on the crashworthiness parameters (i.e., energy absorption and stroke efficiency) and the failure modes of a non-woven kenaf (mat) fiber-reinforced hexagonal composite tube. The composite was prepared and fabricated using the hand-lay-up method; fabrication was followed by axial compression testing using an Instron 3382 machine. Various fiber contents were considered, including 25%, 30%, 35% and 40%. A fiber content of 25% to 30% (mass percent) resulted in the best crashworthiness parameters. Furthermore, the amount of energy absorbed decreased as the fiber content increased, as did the mean crash load and the stroke efficiency. A few distinct failure modes were identified during the experiments, including the progressive failure mode, in which failure begins at the top end of the tube, and the transverse crack failure mode, which is associated with the buckling failure mode; after the crash occurs, the top or bottom end of the hexagonal tube begins to break and is fragmented into small pieces.

Reliability Analysis of Structure System Considering Failure Modes of Strength, Fatigue and Buckling

2008 ◽  
Vol 385-387 ◽  
pp. 257-260 ◽  
Author(s):  
Wei Guang An ◽  
Hai An ◽  
Yong Yi Zhang
Keyword(s):  
Failure Mode ◽  
Damage Mechanics ◽  
Failure Modes ◽  
Structural System ◽  
Structural Element ◽  
Structure System ◽  
Residual Structure ◽  
Calculating Method ◽  
Strength Failure ◽  
Buckling Failure

There could be multi-failure modes in the course of working of the structure system including slender bar members. For example, strength failure, fatigue failure and buckling failure, especially sudden buckling failure would bring large disaster to structure. In this paper, according to Fatigue and Damage Mechanics theory, safe margin expression of the different failure mode of structure (static strength, fatigue and buckling) is given firstly, then by analyzing different failure mode of structural element under static and fatigue loads, and failure mode of the calculating element is confirmed by comparing the failure probability value of different failure mode. In the course of searching for significant failure paths, not only is failure mode that stiffness matrix of structure is zero considered, but also buckling failure mode of compressed residual structure is considered too, so that failure analysis is more reasonable. In the end, the reliability calculating method of the structural system is given, and the validity of the method proposed in this paper is explained combining an example.

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.

Seismic assessment of reinforced concrete columns with short lap splices

2021 ◽  
pp. 875529302199483
Author(s):  
Eyitayo A Opabola ◽  
Kenneth J Elwood
Keyword(s):  
Reinforced Concrete ◽  
Failure Mode ◽  
Failure Modes ◽  
Concrete Columns ◽  
Seismic Assessment ◽  
Rc Columns ◽  
Lap Splices ◽  
Displacement Response ◽  
Force Displacement ◽  
Probable Failure

Existing reinforced concrete (RC) columns with short splices in older-type frame structures are prone to either a shear or bond mechanism. Experimental results have shown that the force–displacement response of columns exhibiting these failure modes are different from flexure-critical columns and typically have lower deformation capacity. This article presents a failure mode-based approach for seismic assessment of RC columns with short splices. In this approach, first, the probable failure mode of the component is evaluated. Subsequently, based on the failure mode, the force–displacement response of the component can be predicted. In this article, recommendations are proposed for evaluating the probable failure mode, elastic rotation, drift at lateral failure, and drift at axial failure for columns with short splices experiencing shear, flexure, or bond failures.

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