scholarly journals A Forensic Engineering Investigation Of a Ladder Failure

2009 ◽  
Vol 26 (2) ◽  
Author(s):  
Nicholas A. Petrucci
Keyword(s):  
Load Capacity ◽  
National Standards ◽  
Shear Load ◽  
Improper Use ◽  
Forensic Engineering ◽  
Left Front ◽  
Engineering Investigation

A Worker (Plaintiff) Fell From A Step-Ladder And Was Injured. The Purpose Of The Forensic Engineering Investigation Was To Determine The Cause(S) Of The Incident, And In Particular, If The Incident Was Caused By A Ladder Defect. The Incident Ladder And A Representative Incident Scene Were Inspected. Various Discovery Documents And The Applicable American National Standards Institute (Ansi) Standard Were Reviewed. A Critique From The Opposing (Defendant) Expert Is Presented And Addressed. The Cause Of The Plaintiff Fall From The Ladder Was Determined To Be Its Sudden Instability Due To The Failure Of A Rivet That Secured The Top Cap To The Left-Front Rail. The Failed Rivet Was Not Recovered. Further Analysis Indicated That The Cause Of The Rivet Failure Was Its Defective Design Coupled With Its Reduction In Shear Load Capacity From Normal And Improper Use Of The Ladder. The Determination Of The Defective Design Of The Rivet Was Confirmed By Subsequent Design Improvements Of The Ladder. The Relevance Of The Analysis Performed Is Discussed. Various Noteworthy Points Are Presented For Consideration For Forensic Engineers Of Various Technical Disciplines.

scholarly journals Forensic Engineering Investigation - pumps And Motors Damaged in A Power Plant Explosion

2011 ◽  
Vol 28 (2) ◽  
Author(s):  
Richard W. Grounds
Keyword(s):  
Power Plant ◽  
Lead Times ◽  
Insurance Carrier ◽  
Secondary Damage ◽  
Plant Personnel ◽  
Forensic Engineering ◽  
The Difference ◽  
Serious Injury ◽  
Engineering Investigation

In Addition To Serious Injury Or Loss Of Life To Plant Personnel, Plant Explosions May Cause Significant direct Or Secondary Damage To Facility Machinery, Resulting In Lost Production Time, Costly Repairs, Or replacement Of The Damaged Equipment.  given The Long Procurement Lead Times And Higher Costs Typically Associated With Engineered Machinery (Machinery Not Available Off-The-Shelf), It Is Crucial To Make An Early Determination Of Whether or Not The Damaged Equipment Is Serviceable And Capable Of Providing Reliable Operation After Repairs, Or if The Machinery Must Be Replaced. The Difference In Cost Between The Two Alternatives Is Substantial To the Owner, Insurance Carrier, And All Invested Parties, Particularly When Production Losses Are Considered.  the Focus Of This Investigation Was Four New Machinery Trains Damaged In A Power Plant Natural Gas explosion That Occurred As Construction Of The Facility Neared Completion. Claims For Replacement Machinery were Filed By Various Risk Management Firms On Behalf Of The Builder And Facility Owners, And were Presented To A Claims Adjusting Firm Enlisted By The Insurance Carriers. Independent Consultants were Engaged By The Owners And Claims Adjuster To Examine The Damaged Machinery And Report Findings to The Engaging Parties, With The Findings Being Considered In The Evaluation Of Whether Or Not The machinery Would Be Serviceable Upon Refurbishment.

scholarly journals Forensic Engineering Investigation Of Leakage At Flanged Windows In Stucco

2004 ◽  
Vol 21 (1) ◽  
Author(s):  
Geoffrey Jillson
Keyword(s):  
Water Entry ◽  
Test Apparatus ◽  
Water Penetration ◽  
Framed Structures ◽  
Forensic Engineering ◽  
Quantitative Results ◽  
The Common ◽  
Wood Frame ◽  
Engineering Investigation

Water Intrusion And Accumulation In The Exterior Envelope Of Wood Frame Structures With Stucco Siding And Flanged Windows Has Been Recognized As A Major Cause Of Damage Characterized By Deterioration Of Sheathing And Framing. Invasive Inspections Of Hundreds Of Wood Framed Structures Constructed In This Manner Have Clearly Shown That The Overwhelming Cause Of Deterioration Has Resulted From Chronic Water Entry Into The Envelope At Window And Door Locations. Substantial Deterioration Has Been Observed In Sheathing And Framing As Early As The Third Season Following Construction With Extensive Deterioration Observed In Many Structures By The Fifth Or Sixth Year Following Construction Manifesting Primarily At Window And Door Penetration Areas In The Envelope. This Study Was Undertaken To Quantitatively Ascertain The Causes Of The Water Entry At Flanged Windows In Stucco Siding Installations And Compare With Water Entry At Wood Windows In Stucco Siding Utilizing Astm E1105-00 Field Determination Of Water Penetration Of Installed Exterior Windows, Skylights, Doors, And Curtain Walls, By Uniform Or Cyclic Static Air Pressure Difference. Effects Of Sealing/Caulking Of The Perimeter Of The Window At The Stucco/Window Intersection Were Also Studied And Quantified Using The Test Apparatus. This Paper Provides A Description Of The Common Construction Conditions And Presents The Quantitative Results Of The Study Of Causes Of Leakage At Flanged Windows In Stucco And The Effect On Leakage Of Sealing/Caulking Of Perimeter Joint.

scholarly journals Experimentally Validated Nonlinear Analysis of Bridge Plate Girders with Deformations

2015 ◽  
Vol 37 (3) ◽  
pp. 53-61 ◽  
Author(s):  
Mieszko Kużawa ◽  
Jan Bień
Keyword(s):  
Nonlinear Analysis ◽  
Load Capacity ◽  
Shear Capacity ◽  
Shear Load ◽  
Structural Behaviour ◽  
Plate Girders ◽  
Bridge Plate ◽  
Experimental Laboratory ◽  
The University

Abstract Comprehensive methodology of numerical nonlinear analysis of the consecutive phases in the structural behaviour of bridge plate girders with deformations is presented. The analysis concerns all stages of structure loading until failure and especially determination of the ultimate shear load capacity. Verification and validation of the numerical procedures proposed is based on comparison of the calculated results with effects of experimental laboratory shear capacity tests of plate girders carried out at the University of Ljubljana.

Discussion on Determination of Non-Methane Hydrocarbons

2014 ◽  
Vol 1073-1076 ◽  
pp. 562-566
Author(s):  
Zhe Min Li
Keyword(s):  
International Standards ◽  
National Standards ◽  
National Standard ◽  
Measure Methods

This paper summarized the measure methods which include both Chinese national standards and international standards of how to determine the concentration of Non-methane Hydrocarbons (NMHC).Some problems and suggestions were discussed in this paper to improve the level of the measure methods and prompt the establishment of relative Chinese national standard.

scholarly journals Corrosion Resistance of Fiber-reinforced Geopolymer Structural Concrete in a Simulated Marine Environment

2021 ◽  
Author(s):  
Khaled Sobhan ◽  
Francisco Martinez ◽  
D.V. Reddy
Keyword(s):  
Corrosion Resistance ◽  
Marine Environment ◽  
Electrochemical Method ◽  
Ordinary Portland Cement ◽  
Load Capacity ◽  
Fiber Reinforced ◽  
Structural Concrete ◽  
Accelerated Corrosion ◽  
Damaged Beams

The corrosion resistance of fly ash-based geopolymer structural concrete (GPC), with or without fibers, was investigated in a simulated marine environment, and compared with that of ordinary Portland cement structural concrete. The corrosion behavior is studied through an electrochemical method for inducing accelerated corrosion. The fiber-reinforced specimens contained polyolefin fibers in the amounts of 0.1%, 0.3%, and 0.5% by volume. Several artificial corrosion conduits were introduced into the specimens reaching up to the rebars. This process enhanced the rate of laboratory corrosion in GPC. The corrosion-damaged beams were then analyzed through a method of crack scoring, and determination of steel mass loss and residual flexural load capacity. The fiber-reinforced corroded GPC beams showed a 24% reduction in crack scores, and a 109% increase in residual flexural load capacity, compared to unreinforced corroded GPC beams. This shows promise of fiber-reinforced GPC as a sustainable structural material in the marine environment.

scholarly journals Forensic Engineering Investigation Of Failure Of An Oil Pipeline

2012 ◽  
Vol 29 (1) ◽  
Author(s):  
William R. Broz
Keyword(s):  
Contaminated Soil ◽  
Fuel Oil ◽  
Weld Repair ◽  
Butt Weld ◽  
Oil Pipeline ◽  
Weld Joints ◽  
General Contractor ◽  
Forensic Engineering ◽  
Engineering Investigation ◽  
Surrounding Soil

A Below-Grade, Nps 12 Pipeline Serving A Major Commercial Marine Terminal Failed At A Flanged Joint, Causing A Major Leak And Contamination Of The Surrounding Soil. The Gasket At The Failed Joint Showed Evidence Of Localized, Radial Through-Leakage. At The Terminal, The Initial Excavation Of Contaminated Soil Caused Minor Damage To Several Non-Leaking Segments Of Pipe And The Author Was First Tasked To Oversee The Related Inspection, Weld Repair And Corrosion Protection Work. The Author Subsequently Performed A Forensic Pipe Stress Analysis Of The Affected Portion Of The Fuel Oil System Per The Governing Pressure Piping Code. The Results Indicated That The Leaking Joint Failed With Respect To The Code Criterion Of Equivalent Pressure. Further Investigation Revealed That The System As Originally Designed Was Entirely Of Butt Weld Construction With No Flanged Joints, And Would Have Complied With All Code Requirements. The Investigation Determined That The General Contractor Had Made An Unauthorized Substitution Of Flanged Joints For Butt Weld Joints, Without Informing The Owner Or Design Engineer Of Record.

scholarly journals Forensic Engineering Investigation Of Dezincification In A Major Corrosion Litigation

2013 ◽  
Vol 30 (1) ◽  
Author(s):  
Robert N. Anderson
Keyword(s):  
Zinc Content ◽  
Building Code ◽  
Insurance Companies ◽  
Urban Location ◽  
Home Owner ◽  
Plumbing Systems ◽  
Forensic Engineering ◽  
Low Strength ◽  
Engineering Investigation

Zinc-Rich Brasses With The Zinc Content Above 30% Can Be Involved In Corrosion Processes With Catastrophic Results. The Dezincification Results In A Low Strength Copper With A Porous Sponge Like Structure. The Case, Where Dezincification Occurred With Massive Impact, Involved 34,000 New Homes In An Urban Location In Nevada. These Homes Were Constructed Using Building Code Approved Plastic Pex Tubing For Plumbing With Brass Fittings. Leaks Developed In The Home Plumbing Systems After Approximately 3-6 Years. This Failure Resulted In Lawsuits Involving Home Owner Associations, Insurance Companies, Contractors, Plumbers, Architects, Manufacturers, And Suppliers.

scholarly journals Forensic Engineering Investigation of Above-Ground Pool Submersion Accidents

2015 ◽  
Vol 32 (2) ◽  
Author(s):  
Richard Ziernicki ◽  
William H. Pierce
Keyword(s):  
United States ◽  
The United States ◽  
Swimming Pool ◽  
Consumer Product Safety Commission ◽  
Adult Supervision ◽  
Forensic Engineering ◽  
Product Defect ◽  
Engineering Investigation ◽  
Alternative Designs

In the United States, approximately 35 children under the age of five years old drown each year after access-ing above-ground pools via pool ladders. Consumer Product Safety Commission (CPSC) data also shows that approximately 486 additional children sustain submersion-related injuries after accessing above-ground pools via pool ladders. In many cases, these events occurred during brief lapses of adult supervision. This paper fo-cuses on potential product defect issues related to child submersion accidents, including the role of user manuals, alternative designs, warnings, instructions, and child behavior testing. The authors examine the issues related to the investigation of above-ground swimming pool submersion accidents. In addition, procedures and steps are outlined that may be useful in analyzing whether the swimming pool is defective and unreasonably dangerous.

scholarly journals Forensic Engineering Analysis of a Fatal Trailer Wheel-Separation Failure

2017 ◽  
Vol 34 (2) ◽  
Author(s):  
Stephen A. Batzer
Keyword(s):  
Forensic Analysis ◽  
Front Wheel ◽  
Engineering Analysis ◽  
Passenger Compartment ◽  
Traffic Lane ◽  
Forensic Engineering ◽  
Cantilever Bending ◽  
Winter Time ◽  
Separation Failure ◽  
Left Front

A forensic analysis of a fatal trailer wheel-separation failure is presented in this paper. An older three-axle trailer carrying snowmobiles was being driven at highway speed during winter time in Michigan. The left front wheel detached due to the catastrophic failure of all six lug studs. The wheel traveled into the on-coming traffic lane and struck the roof of a sedan driven by a local student. The driver of this vehicle was killed instantly due to passenger compartment intrusion. One possibility was that the lug nuts were improp-erly tightened during a recently performed service — and that this looseness diminished clamping forces and led to cantilever bending of the studs and fatigue fracture. An analysis of the defendant’s narrative and of the failure were performed.

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