Perforation Modes of Double-Layered Plates With Air Gap Struck by a Blunt Rigid Projectile

2016 ◽  
Author(s):  
Chen Xiaowei ◽  
Liu Bing
Keyword(s):  
Failure Mode ◽  
Failure Modes ◽  
Adiabatic Shear ◽  
Air Gap ◽  
Steel Plates ◽  
Layered Plates ◽  
Final Failure ◽  
Rigid Projectile ◽  
Experimental Analyses ◽  
Shear Plugging

The failure modes of the perforation of double-layered or multi-layered plates may be quite different. Further experimental analyses are conducted on the perforations of single and double-layered Weldox E steel plates with air gap to discuss the different perforation modes. It indicates that, in case of higher initial striking velocity, the failure mode of the first layer plate is adiabatic shear plugging, whilst the failure mode of the second layer plate is adiabatic shear plugging or shear plugging as the striking velocity of the projectile slows down. It concludes that the final failure mode of the double-layered plates is the hybrid of shear plugging and adiabatic shear plugging.

scholarly journals Bending behavior of single hat-shaped composite T-joints under out-of-plane loading for lightweight automobile structures

2018 ◽  
Vol 37 (12) ◽  
pp. 808-823 ◽  
Author(s):  
Wenbin Hou ◽  
Xianzhe Xu ◽  
Haifeng Wang ◽  
Liyong Tong
Keyword(s):  
Failure Mode ◽  
Failure Modes ◽  
Flexural Modulus ◽  
Peak Load ◽  
Failure Criteria ◽  
Failure Behavior ◽  
Molding Process ◽  
T Joints ◽  
Final Failure ◽  
Out Of Plane

This paper presents an analytical, numerical, and experimental study on the failure behavior of single hat-shaped T-joints made of plain woven carbon fiber polymer (T300/epoxy 618) and subjected to out-of-plane bending. The T-joint is manufactured by vacuum bag molding process at room temperature. An analytical model is developed to analyze the experimental results and to establish the associated failure criteria. Two failure modes: (a) laminate buckling and (b) laminate crushing are considered, and the theoretical relationships for predicting the failure load associated with each of the two modes were developed. The experimental data correlate closely with the analytically predicted behavior, including failure mode and bending stiffness. In particular, both laminate buckling and laminate crushing are observed during the experiment with laminate crushing being the final failure mode, which can be considered to be the most important failure mode of the fabricated T-joint. In addition, numerical simulations based on the finite element method and the Hashin damage criteria also accurately predict the flexural modulus, the peak load, and failure locations of the T-joint obtained in the test.

Numerical Simulations of the Perforation in Metal Plates with Different Conical-Nosed Projectiles

2014 ◽  
Vol 518 ◽  
pp. 47-52
Author(s):  
Wei Hai Sun ◽  
Gui Ling Ju ◽  
Ban Quan Yang
Keyword(s):  
Numerical Simulations ◽  
Constitutive Relation ◽  
Test Data ◽  
Failure Modes ◽  
Cone Angle ◽  
Steel Plates ◽  
Metal Plates ◽  
Protective Structures ◽  
Shear Plugging ◽  
Good Agreement

Numerical simulations with ABAQUS/Explicit into which Johnson-Cook constitutive relation is incorporated, are performed to study the perforation of Weldox 460E steel plates struck normally by conical-nosed projectiles with different cone angles. Different failure modes and perforation process are obtained. Numerical results are found to be in good agreement with available test data. It is revealed that with increasing cone angle, the failure modes of metal plates become to shear plugging from ductile hole enlargement, and the ballistic limits decrease with that. The conclusions are helpful for the design of protective structures.

Can the Internet Survive Democracy?

2018 ◽  
Author(s):  
Yochai Benkler ◽  
Robert Faris ◽  
Hal Roberts
Keyword(s):  
Failure Mode ◽  
Political Institutions ◽  
Failure Modes ◽  
Political Organization ◽  
The Internet ◽  
The Third ◽  
Final Failure ◽  
Sustained Effort ◽  
Data Informed ◽  
Over Time

This chapter examines whether the internet can—or cannot—contribute to democratization, and under what conditions. This chapter discusses five major failure modes that limit the benefits of decentralized digitally-mediated collective action. The first is the failure to convert from a moment’s surge of decentralized passion into a longer-term, sustained effort with competence to engage political institutions systematically over time. The second is the failure to sustain the decentralized openness in the transition to more structured political organization. The third failure mode of the internet and democracy refers to the power of well-organized, data-informed central powers to move millions of people from the center out, instead of the other way around. The fourth failure mode is that precisely what makes decentralized networks so effective at circumventing established forms of control can also make them the vehicles of repressive mobs. The final failure mode is the susceptibility to disinformation and propaganda.

scholarly journals An Experimental Investigation on the Failure Behavior of a Notched Concrete Beam Strengthened with Carbon Fiber-Reinforced Polymer

2015 ◽  
Vol 2015 ◽  
pp. 1-17 ◽  
Author(s):  
Xia Huang ◽  
Jian Wang ◽  
Feng Zhang ◽  
Song-shan Niu ◽  
Jun Ding
Keyword(s):  
Bearing Capacity ◽  
Failure Mode ◽  
Concrete Beam ◽  
Failure Modes ◽  
Shear Failure ◽  
Interfacial Shear Stress ◽  
Failure Behavior ◽  
Cfrp Laminate ◽  
Final Failure ◽  
Parametric Analyses

This paper presents an experiment investigation on the failure behavior of a notched concrete beam reinforced with CFRP, by exploring the influences of the length, thickness, and CFRP bonding methods on the ultimate bearing capacity and failure mode. The interfacial shear stress has first been analytically derived and parametric analyses are then made to predict the failure mode. The experiment observation finds that failure mode significantly depends on CFRP length. The brittle fracture occurs only for nonstrengthened beams; the shear failure I mode mainly occurs when CFRP laminate is 100 mm long; the shear failure II mode mainly occurs when CFRP laminate is 200 mm long; and the delamination failure mode mainly occurs when CFRP laminate is 350 mm long. Meanwhile, the thickness and the bonding methods of CFRP also influence the final failure modes in terms of CFRP length. The measurement on ultimate load shows that an increase in the length of CFRP up to 200 mm significantly improves the bearing capacity of the reinforced beam. A comparison between a theoretical analysis and the experimental observation shows a good agreement in terms of failure modes indicating the accuracy and the validity of the experiment.

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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