scholarly journals Forensic Engineering Analysis of Common Failures and Inspection Procedures for Residential and Commercial Chairs

2020 ◽  
Vol 36 (1) ◽  
Author(s):  
Anthony Sasso
Keyword(s):  
Paper Industry ◽  
Engineering Analysis ◽  
Safety Standards ◽  
Root Cause ◽  
Maintenance Program ◽  
Cause Of Failure ◽  
Forensic Engineering ◽  
Inspection And Maintenance ◽  
Materials Used ◽  
Mechanism Of Failure

Chairs have been designed, manufactured, and used by humans for thousands of years. Eventually, all chairs wear out and fail. When someone is injured due to this failure, costly litigation can ensue. Forensic engineers are consulted to investigate the root cause of failure, and whether the mechanism of failure could have been detected prior to the accident to avoid injury. Materials used in chair manufacturing and several examples of failures are discussed in this paper. Industry safety standards and manufacturers’ guidelines are used as a basis for a proposed inspection and maintenance program for chair owners.

scholarly journals Forensic Engineering Investigation Of Sectional Ladder Treestand Failures

2013 ◽  
Vol 30 (2) ◽  
Author(s):  
Jahan Rasty
Keyword(s):  
Structural Strength ◽  
Standard Requirement ◽  
Root Cause ◽  
Section Modulus ◽  
Minimum Requirements ◽  
Cause Of Failure ◽  
Forensic Engineering ◽  
Trade Names ◽  
Testing Standards ◽  
Engineering Investigation

The Purpose Of This Forensic Engineering Investigation Was To Determine The Root-Cause Of Failure Of Three 15-Foot Sectional Ladder Treestands That Caused Injury To Users. All Three Treestands Were Identical In Design And Manufactured By The Same Company Despite Differences In Trade Names. Within A Reason-Able Degree Of Scientific And Engineering Certainty, It Was Concluded That Failure Of The Treestands Was The Result Of Overstressing The Star-Crimped Area Of The Treestands At Adjoining Ladder Sections. Overstressing Was Caused By A Designed Reduction In Section Modulus Of The Rail At Adjoining Ladder Sections. Further, The Load-Bearing Ability Of The Ladder Treestands Was Evaluated In Accordance With Com-Monly Accepted Engineering Principles For Metal Ladder Design (Ansi A14.2-2007). Analysis Revealed That The Structural Strength Of The Rail Section And Testing Standards For The Treestand Industry Are Lack-Ing When Compared To Portable Metal Ladders Designed For Identical Load Ratings. In Fact, The Treestands Failed To Meet The Standard Requirement For A Portable Metal Ladder Rated At 170-Pounds Even When The Treestand Was Tested At ½ Of Its Spanning Length (2-Sections). Comparisons Between The Treestands And Portable Metal Ladder Standards Indicated That The Treestands Failed To Meet Minimum And Generally Accepted Standards For Ladder Design And Suggested The Treestands Do Not Meet Minimum Requirements For Merchantability.

scholarly journals Residual Stress Measurement Tools and Methods: Industrial View of Current Gaps and Opportunities

2021 ◽  
Author(s):  
Seung-Yub Lee ◽  
Iuliana Cernatescu ◽  
David U. Furrer
Keyword(s):  
Residual Stress ◽  
Stress Measurement ◽  
Model Development ◽  
Residual Stress Measurement ◽  
Safety Standards ◽  
Root Cause ◽  
Cause Of Failure ◽  
Pros And Cons ◽  
Development And Validation ◽  
Tools And Methods

Abstract Residual stress measurement is necessary in several aspects of product development and sustainment: structural analysis of components, process quality validation, model development and validation, and understanding the root-cause of failure events. Especially in the aerospace industry, accurate residual stress assessment is critical due to the higher safety standards. However, limited tools and methods are available for different components and applications. Goal of this presentation is to review pros and cons of the various methods, discuss the technical challenges in stress determination, and introduce potential solutions to overcome the current limits.

scholarly journals Forensic Engineering Analysis Of Vapor Transmission During Re-Roofing Project

2013 ◽  
Vol 30 (1) ◽  
Author(s):  
Paul Swanson
Keyword(s):  
Adverse Effects ◽  
Preventive Measures ◽  
Forensic Analysis ◽  
Building Construction ◽  
Construction Process ◽  
Engineering Analysis ◽  
Forensic Engineering ◽  
Building Environment ◽  
Materials Used

Roof Replacement Projects Are Routinely Conducted When A Building Is Occupied. Normal Safety Protocols That Control The Execution Of The Work And The Materials Used Are Specified In The Project Manual To Protect The Building Environment From Adverse Effects During The Course Of The Work. This Is A Case Where The Normal Protocols Were Insufficient To Protect The Building Occupants From Exposure To Vapors Present During The Construction Process. The Resulting Forensic Analysis Revealed That Elements Of The Building Construction Provided The Mechanism For Vapor Transmission That Together With Standard Preventive Measures Actually Created A Condition That Could Increase The Concentration Of Vapors Within The Building.

scholarly journals Forensic Engineering Analysis of Toilet Connector Failures in a Class-Action Lawsuit

2015 ◽  
Vol 32 (2) ◽  
Author(s):  
James William Jones
Keyword(s):  
Class Action ◽  
Finite Element Analyses ◽  
Engineering Analysis ◽  
Root Cause ◽  
Industry Standards ◽  
Creep Analysis ◽  
Strength Tests ◽  
Single Overload ◽  
Forensic Engineering ◽  
Injection Molded

A major manufacturer of water supply lines that connect flushable toilets to house water piping was the object of a class-action lawsuit. The author examined a large number of failed and exemplar connectors, complete fill lines, and similar injection-molded products as well as visited failure sites with the goal of ascertaining the root cause of the failures. Forensic work included strength tests and finite element analyses to determine the expected life of the nuts, including single overload failure strength and creep analysis to predict life. Tightening tests using random subjects were conducted. A statistical analysis of the failures was also performed. The products of competing manufacturers were evaluated for comparison of similar designs. After much investigation and analysis, it was concluded that the design of the connector was not defective and met relevant industry standards.

scholarly journals Forensic Engineering Use Of The Safety Hierarchy

2005 ◽  
Vol 22 (1) ◽  
Author(s):  
John N. Schwartzberg
Keyword(s):  
Forensic Analysis ◽  
Case Histories ◽  
Analytical Technique ◽  
Root Cause ◽  
Hazard Control ◽  
Hazard Avoidance ◽  
Cause Of Failure ◽  
Forensic Engineering ◽  
Process Failures

The Safety Hierarchy Is A Recognized Linear Logical Approach To Hazard Control Most Commonly Utilized By Safety Professionals In Hazard Avoidance. In This Paper, Use Of This Method Of Analysis Is Introduced As A Method Of Forensic Analysis Of Product Failures, Workplace And Premises Liability Accidents, And Process Failures To Help Identify The Root Cause Of Failure And The Role Of The Responsible Entity In Causation. Examples And Case Histories Will Be Used To Demonstrate The Effectiveness Of The Analytical Technique.

Identifying the Root Cause of Source-Drain Leakage Caused Soft Fail in Advanced Bulk FinFET Devices

2018 ◽  
Author(s):  
Liangshan Chen ◽  
Yuting Wei ◽  
Tanya Schaeffer ◽  
Chongkhiam Oh
Keyword(s):  
Careful Analysis ◽  
Physical Analysis ◽  
Device Structure ◽  
Tem Analysis ◽  
Root Cause ◽  
3D Architecture ◽  
Cause Of Failure ◽  
Electrical Analysis ◽  
Electrical Data

Abstract The paper reports the investigation on the root cause of source-drain leakage in bulk FinFET devices. While the failing device was readily isolated by nanoprobing technique and the electrical analysis pinpointed the potential defect location inside the Fin channel, the identification of physical root cause went through extreme challenges imposed by the tiny-sized device and the unique FinFET 3D architecture. The initial TEM analysis was misled by the projection of a species in the lamella surface and thus could not explain the electrical data. Careful analysis on the device structure was able to identify the origin of the species and led to the discovery of the actual root cause. This paper will provide the analysis details leading to the findings, and highlight the role of electrical understanding in not only providing guidance for physical analysis but also revealing the true root cause of failure in FinFET devices.

Failure Localization in a Multistage S-Band Power Amplifier

2016 ◽  
Author(s):  
Clarence Rebello ◽  
Ted Kolasa ◽  
Parag Modi
Keyword(s):  
Output Power ◽  
Power Amplifier ◽  
Fault Tree ◽  
Root Cause ◽  
Failure Investigation ◽  
Band Power ◽  
Cause Of Failure ◽  
Design Materials ◽  
Board Level ◽  
Failure Localization

Abstract During the search for the root cause of a board level failure, all aspects of the product must be revisited and investigated. These aspects encompass design, materials, and workmanship. In this discussion, the failure investigation involved an S-Band Power Amplifier assembly exhibiting abnormally low RF output power where initial troubleshooting did not provide a clear cause of failure. A detailed fault tree drove investigations that narrowed the focus to a few possible root causes. However, as the investigation progressed, multiple contributors were eventually discovered, some that were not initially considered.

Case Study—Failure Analysis of a Multiplexer

2016 ◽  
Author(s):  
Michael Woo ◽  
Marcos Campos ◽  
Luigi Aranda
Keyword(s):  
Failure Analysis ◽  
High Reliability ◽  
Component Failure ◽  
Root Cause ◽  
Knowing That ◽  
Cause Of Failure ◽  
The Cost

Abstract A component failure has the potential to significantly impact the cost, manufacturing schedule, and/or the perceived reliability of a system, especially if the root cause of the failure is not known. A failure analysis is often key to mitigating the effects of a componentlevel failure to a customer or a system; minimizing schedule slips, minimizing related accrued costs to the customer, and allowing for the completion of the system with confidence that the reliability of the product had not been compromised. This case study will show how a detailed and systemic failure analysis was able to determine the exact cause of failure of a multiplexer in a high-reliability system, which allowed the manufacturer to confidently proceed with production knowing that the failure was not a systemic issue, but rather that it was a random “one time” event.

Troubleshooting Cable Deployed Thru Tubing Electrical Submersible Pumps: A Case Study from South East Asia

2021 ◽  
Author(s):  
Saurabh Anand ◽  
Eadie Azahar B Rosland ◽  
Elsayed Ouda Ghonim ◽  
Latief Riyanto ◽  
Khairul Azhar B Abu Bakar ◽  
...  
Keyword(s):  
Low Cost ◽  
Power Cable ◽  
Related Data ◽  
Root Cause ◽  
Artificial Lift ◽  
Electrical Submersible Pumps ◽  
Cause Of Failure ◽  
Water Cut ◽  
Discharge Pressure

Abstract PETRONAS had embarked on an ambitious thru tubing ESP journey in 2016 and had installed global first truly rig less offshore Thru Tubing ESP (TTESP) in 2017. To replicate the success of the first installation, TTESP's were installed in Field – T. However, all these three TTESP's failed to produce fluids to surface. This paper provides the complete details of the troubleshooting exercise that was done to find the cause of failure in these wells. The 3 TTESP's in Field – T were installed as per procedure and was ready to be commissioned. However, during the commissioning, it was noticed that the discharge pressure of the ESP did not build-up and the TTESP's tripped due to high temperature after 15 – 30 mins of operation. Hence none of the 3 TTESP's could be successfully commissioned. Considering the strategic importance of TTESP's in PETRONAS's artificial lift plans, detailed troubleshooting exercise was done to find the root cause of failure to produce in these three wells. This troubleshooting exercise included diesel bull heading which gave some key pump performance related data. The three TTESP's installed in Field – T were of size 2.72" and had the potential to produce an average 1500 BLPD at 80% water cut. The TTESP deployment was fully rigless and was installed using 0.8" ESP power cable. The ESP and the cable was hung-off from the surface using a hanger – spool system. The entire system is complex, and the installation procedure needs to be proper to ensure a successful installation. The vast amount of data gathered during the commissioning and troubleshooting exercise was used for determining the failure reason and included preparation of static and dynamic well ESP model. After detailed technical investigative work, the team believes to have found the root cause of the issue which explains the data obtained during commission and troubleshooting phase. The detailed troubleshooting workflow and actual data obtained will be presented in this paper. A comprehensive list of lessons learnt will also be presented which includes very important aspects that needs to be considered during the design and installation of TTESP. The remedial plan is finalized and will be executed during next available weather window. The key benefit of a TTESP installation is its low cost which is 20% – 30% of a rig-based ESP workover in offshore. Hence it is expected that TTESP installations will pick-up globally and it's important for any operator to fully understand the TTESP systems and the potential pain points. PETRONAS has been a pioneer in TTESP field, and this paper will provide details on the learning curve during the TTESP journey.

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