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Mitigating tornado damage remains a critical challenge for communities throughout much of the United States. Enhanced construction techniques typically used in hurricane-prone regions are often recommended as at least part of the solution, but the effectiveness of these techniques lacks empirical evaluation. This study investigates the performance of modern wood-frame residential structures in Arabi, LA, constructed to hurricane-resistant standards, that were impacted by a strong tornado on March 22, 2022. Field teams deployed beginning March 25, 2022, just three days after the tornado touched down, capturing perishable data on the building performance using vehicle-mounted surface-level panoramic cameras, forensic engineering investigations, and unmanned aerial systems. This paper describes the field deployments and identifies common failure mechanisms observed by the field teams. Analytical fragility functions are developed based on the load path observations and compared to empirical fragility functions generated from linking the building performance observations with wind speed estimates at each building derived from a parametric wind field model conditioned to tree-fall patterns. The study finds that despite the frequent use of hurricane-resistant hardware, such as hurricane straps and anchor bolts, key weak links elsewhere in the load path compromised the resistance and led to premature failures. The agreement between the empirically- and analytically-derived fragility functions was lacking, demonstrating the challenges that remain in understanding near-surface tornado wind loading and structural response. Nonetheless, the study provides a consensus framework for future tornado assessments that can help improve our understanding of tornado loading through the utilization of reconnaissance data. Further, the study findings on deficiencies in the load paths of homes in hurricane-prone regions have practical value to risk assessments and future construction practices. [ABSTRACT FROM AUTHOR]

This paper describes the structural aspects of the Wieselburg Bridge collapse in Austria. The original design and reinforcing details for this integral concrete bridge are discussed. The collapse of the bridge is re‐constructed based on forensic documentation of the failure. The results of structural analysis carried out using material properties obtained after failure are compared to the shear capacity obtained from various models and from test results from literature. The results are used to explain the cause of failure of the integral bridge under dead load. [ABSTRACT FROM AUTHOR]

Forensic engineers and crash safety researchers sometimes use the injuries of a seatbelted occupant to infer the injury risk of an unbelted occupant in the same crash, had they instead been wearing a seatbelt. It is unclear, however, whether this inference is valid or how often two occupants in the same collision have similar injuries. Here, we sought to compare the injury outcomes between drivers and front‐seat passengers in frontal collisions using real‐world collision data. We compared the injury severity, quantified using the Abbreviated Injury Scale (AIS), of 22 injury categories between front‐seat occupants with matching seatbelt use and airbag deployment in single‐event frontal collisions recorded in the publicly available National Automotive Sampling System, Crashworthiness Data System (years 1993–2015) database to assess whether they had similar severity injuries. We analyzed the four combinations of seatbelt use and airbag deployment and all seatbelt/airbag conditions combined. In only 3 of 88 combinations of injuries and seatbelt/airbag conditions did more than 50% of occupant pairs have the same AIS score, although the related confidence intervals showed these proportions were not significantly greater than 50%. In contrast, we found 19 combinations of injuries and seatbelt/airbag conditions where one occupant was consistently injured more severely than the other. Our findings show that injury outcome is not similar for both front‐seat occupants in the same frontal collision with similar seatbelt and airbag conditions; however, one may be able to predict that one occupant would be more severely injured than their fellow occupant. [ABSTRACT FROM AUTHOR]

The PowerPlex Fusion 6C PCR™ amplification kit provides a strong discriminatory power for human identification. We have validated the kit with a reduced volume (12.5 µL) and as part of the validation we compared the efficiency of the polymerase chain reaction (PCR) prepared manually and on Hamilton Microlab® Autolys STAR Biorobot. Three years of casework data has been also included in the validation. Optimisation was carried out on different types of samples (blood, saliva, semen) and DNA was extracted robotically. Tests were conducted at two different cycle numbers (30;32), followed by analysis on both the Applied BiosystemsTM 3500 and 3500 xL Genetic Analyzer instruments (Applied Biosystems®, Foster City, CA, USA). When the PCR was prepared manually, no allele dropout was observed over 0.15 ng input DNA. Whereas when the PCR was prepared robotically, dropout already appeared at the level of 0.15 ng input DNA. In cases when increased cycle number was utilised, an increasing number of dropouts started to arise from 0.075 ng total input DNA. Despite the fact that robotically prepared PCR produced more missing alleles than the manually prepared PCR, using the optimal 0.5 ng input DNA, both methods proved to be reliable. Based on the results, our half-volume protocol is robust, and after three years of application it has proven to be effective with respect to a large number of casework samples. [ABSTRACT FROM AUTHOR]

Copyright of REDER: Revista de Estudios Latinoamericanos sobre Reducción del Riesgo de Desastres is the property of Corporacion Gestion de Riesgos y Desastres (GRID-Chile) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The study of bite marks provides crucial elements that contribute towards identifying the biter. In many cases, it assumes importance when bite marks are detected on the body of a victim of violence, but it could also be relevant when the bite marks are seen on food substances at the crime scene. In both circumstances, comparing the bite marks with a suspect's dentition can be decisive in confirming or excluding the culpability. In this case report, a bun (bread roll) with the sign of a bite was found at the crime scene. We report a pilot study using 3D reproduction of the bite mark on the bun and dental models of the alleged biter and the victim. A reverse engineering process was used to obtain digital 3D models of the bitten bun and the dental models by taking numerous photographs and stitching them together using a software called Metashape by Agisoft. The last step was to compare the bitemark to the two dental models, evaluating the spatial distance, the degree of overlap, and the degree of interpenetration. The results confirmed the usefulness of reverse engineering in forensic investigations showing the compatibility between the victim's teeth and the bite mark on the bun. [ABSTRACT FROM AUTHOR]

OSHA regulations and industry-accepted standards are intended to be used in conjunction to help prevent worker injury. Despite the aforementioned intention, a point of operation injury occurred to an employee while he was operating a hydraulic rotary bending machine. The machine had been retrofitted with a two-hand control device that was intended to act as a means of point of operation safeguarding. A forensic engineering analysis of both the electromechanical design and programmable logic code -- combined with a performance and prescriptive requirement analysis -- ultimately revealed flaws in the design of the electromechanical system and software design. It also demonstrated a lack of adherence to the applicable industryaccepted standards related to machine guarding. These factors led to the point of operation injury. [ABSTRACT FROM AUTHOR]

The American Society of Civil Engineers/Structural Engineering Institute (ASCE/SEI) 7 standard is utilized to determine design wind loading on buildings and other structures. However, it can also be utilized in a forensic capacity to approximate a wind speed that would cause specific conditions to occur, such as the overturning of a structure. This paper provides a brief overview of the ASCE/SEI 7 method for wind loading and discusses the use of various adjustment factors used to determine the wind on structures, including wind directionality factor, velocity pressure coefficient, topographic factor, and the ground elevation factor. A clear understanding of these factors -- and how to apply them -- is crucial to estimating a wind speed and resulting force to cause a particular event or condition to occur. [ABSTRACT FROM AUTHOR]

During the coating of a natural gas pipeline, all 14 bolts securing the pedestal of a crane boom to a truck bed failed, causing the boom to fall and strike a worker in the head. The bolts exhibited excessive corrosion indicative of exposure to a harsh corrosive environment prior to the failure. Review of provided documents revealed that the crane was kept in an uncovered yard for two years. Afterward, it was rented to petrochemical companies for use in heavy oil and gas industrial environments. The fracture surfaces of the bolts revealed signs of excessive fatigue, which were determined to be caused by loadings that the previous renters of the crane had subjected it to. Bolt fatigue drastically reduced their strength, allowing them to fail under loads well below the recommended load capacity of the crane. Maintenance records indicated that the lessor failed to perform adequate inspection of the crane, allowing bolt corrosion and fatigue to go unnoticed. Had proper inspections and maintenance instructions been provided and performed, the incident would not have occurred. [ABSTRACT FROM AUTHOR]

High levels of cobalt and chromium ions were detected in the bodies of multiple recipients of modular cobalt chrome molybdenum metal-on-metal hip implants, necessitating the revision of their implants. A forensic engineering investigation of provided discovery documents and existing literature regarding the design, manufacturing, and clinical testing of these modular hip implants was performed. The investigation revealed that the modular interfaces of the implant allowed for micromotion to induce mechanically assisted crevice corrosion at these surfaces. The debris from this corrosion resulted in the release of metal ions into the bodies of the users, forming pseudotumors and compromising the user's health and wellbeing. The effect of this corrosion was enhanced by the galvanic couple that existed between the modular components of the implant. In addition, scanning electron microscopy (SEM) and electron dispersive spectroscopy (EDS) analysis identified silicon carbide (SiC) and aluminum oxide (AL2O3) particles left behind from polishing, which were embedded in the ball and liners. These particles accelerated the wear of the hip implant and further exacerbated the release of metal ions. The designers of future hip implants should take care in preventing the occurrence of the above-stated factors. [ABSTRACT FROM AUTHOR]

Forensic engineers are commonly asked to develop conceptual scopes of repair as part of their work. Many factors impact these recommendations, including building codes, construction feasibility, manufacturer assessment, and installation requirements. In addition, the conditions present on and within the existing roof surfaces can limit the repairability of a commercial roof assembly such that removal and replacement of the entire roof section is the appropriate or only feasible repair option. This paper will focus on common limitations to be considered when developing a conceptual scope of repair for common commercial roof systems, including single-ply membranes, built-up roofing, metal panel roofing, spray polyurethane foam roofing, and the application/maintenance of roof coatings. It will also discuss an assessment methodology that can assist in developing a broader understanding of the condition of the roof surfaces. [ABSTRACT FROM AUTHOR]

An arc flash and fire in the secondary compartment of an industrial facility utility transformer resulted in destruction of newly installed electrical metering equipment. Inherent to this type of event are two loss-ofevidence challenges: extremely high heat burns or melts everything nearby, and urgency to restore normal operation may prevent comprehensive examination of the scene. The facility contractor's operations staff conducted an initial root cause analysis. The contractor's management called on an external forensic team to provide an independent assessment. Having an established investigation methodology allows the forensic examiner to better understand what was, and was not, evaluated by facility staff and prevents confirmation biases. This paper examines the facility's report, addresses shortcomings in its conclusions, and goes on to detail the methods and reasoning behind the forensic team's findings. The methodology presented in this paper is applicable to a wide range of industrial electrical fires. [ABSTRACT FROM AUTHOR]

The aim of the paper is to verify the applicability of the T2GO skiddometer for measuring the coefficient of friction for forensic practice in accordance with the legislative framework of the Czech Republic. In the introduction, the article discusses the problem of friction coefficient measurement. The results of the comparison with dynamic measuring devices used in the Czech Republic and the determination of the mutual compliance rate with these devices, based on data obtained within the National Comparative Measurement Action, are presented. The article concludes with an interpretation and discussion of the results. In cases where no sufficient mutual compliance was found, an analysis and reasoning of these results is provided. Last but not least, based on the results, a procedure is proposed for future use of the T2GO skiddometer in practice within the legislative conditions of the Czech Republic.

Forum papers are thought-provoking opinion pieces or essays founded in fact, sometimes containing speculation, on a civil engineering topic of general interest and relevance to the readership of the journal. The views expressed in this Forum article do not necessarily reflect the views of ASCE or the Editorial Board of the journal. [ABSTRACT FROM AUTHOR]

The aim of the paper is to verify the applicability of the T2GO skiddometer for measuring the coefficient of friction for forensic practice in accordance with the legislative framework of the Czech Republic. In the introduction, the article discusses the problem of friction coefficient measurement. The results of the comparison with dynamic measuring devices used in the Czech Republic and the determination of the mutual compliance rate with these devices, based on data obtained within the National Comparative Measurement Action, are presented. The article concludes with an interpretation and discussion of the results. In cases where no sufficient mutual compliance was found, an analysis and reasoning of these results is provided. Last but not least, based on the results, a procedure is proposed for future use of the T2GO skiddometer in practice within the legislative conditions of the Czech Republic. [ABSTRACT FROM AUTHOR]

The near ubiquitous presence of numerical simulation has made case‐specific calculations of body temperatures following death possible so that accurate calculations of body temperatures can provide valuable information for estimating the time of death and can aid in forensic investigations. Here, a computational approach is described that has been validated against multiple, independent, and experimental investigations. The approach only requires one subjective input parameter (the heat transfer coefficient). A simple algorithm serves as a guidepost to the selection of this parameter. The algorithm incorporates clothing and the space in which the body is housed. Heat transfer coefficients that range from h = 2 W/m2/°C for bodies that are heavily clothed to h = 9 W/m2/°C for bodies that are nude (in air). The method also requires setting of ambient temperature conditions (ambient temperature)—however, that input is often available. The paucity of inputs makes this technique remarkably easy to employ. The new method is also able to calculate cadaver cooling rates for situations where the cadaver is in a timewise or spatially changing thermal environment (diurnal temperature variations, bodies partially submerged in water, changes to weather, insolation, etc.). Results from the present calculations are compared with a large body of measurements from the literature; it was found that the predictions and measurements were in excellent agreement, regardless of the ambient temperature conditions and the nature of the clothing of the body. This new calculation approach can be used with reasonable accuracy for determining cadaver cooling and time since death. [ABSTRACT FROM AUTHOR]

Since comics are known as an increasingly popular modern educational strategy which have not been common in university classes so far, this paper represents a creative attempt to change this practice. Namely, we believe that a good comic, or more precisely an educational-scientific comic, could be a useful tool for teaching, bringing about change and inventiveness, and connecting topics and narratives in a multitude of registers. Additionally, we believe that the potential of university teaching can be increased by combining comics and foreign language teaching, not only due to the already mentioned interest in comics as a language method but also due to its multidisciplinarity and the possibility of interfaculty cooperation as a completely new language practice, hitherto unexamined or insufficiently tested in language learning. The paper first discusses the arguments for and against the use of comics in teaching foreign languages, and then offers a practical overview on how to create a comic. Finally, we present our experiences in achieving interfaculty cooperation. In other words, this paper intends to shed light on three aspects: (1) promoting the idea of the teacher as a creator of innovative materials and strategies in education; (2) using comics as a language activity; and (3) the intellectual flexibility of students and lecturers in using comics at two different faculties. The research was conducted with the students of the Department of Geology of the Faculty of Mining and Geology of the University of Belgrade, and with the students of the Department of Forensic Engineering of the Belgrade University of Criminal Investigation and Police Studies. [ABSTRACT FROM AUTHOR]

In 1975, a manufacturer was awarded a contract to produce modular air-traffic control towers for the U.S. Navy. The specifications called for painted steel siding, but the manufacturer convinced the Navy to substitute aluminum-bonded-to-plywood panels that were provided by a supplier. In less than one year, the panels began to delaminate, and the aluminum began to crack. It was found that the failure was the result of chloride-induced intergranular corrosion caused by chemicals in the adhesive and excessive moisture in the wood introduced during manufacturing. [ABSTRACT FROM AUTHOR]

A review of forensic structural engineering, which is a strategy that follows after bridge failure, is presented in the paper. A detailed statistical analysis, and worldwide systematisation of available bridge failure data for the 1966-2020 period, are given. More than six hundred cases of partial or full collapse of bridges are analysed in detail, and causes that have led to their failure are examined. Failure of each of these bridges was in most cases not caused by a single factor, i.e. the main cause was most often just a trigger in the cause-and-effect sequence of events that contributed to such failure. Consequently, in addition to main causes, the influence of human factor, as a precondition leading to failure, is considered in each of the analysed cases. Types of progressive collapse, being a critical structural failure mechanism, are described in the second part of the paper, with an emphasis on bridges. An overview of the theory of structural robustness is also given. Design guidelines and approaches, aimed at preventing catastrophic failure and creating more robust structures, are presented. Methods for achieving robustness in the design of new bridges and in the strengthening of the existing ones are also described, and practical real-life examples are provided.

Computer models are useful for both structural design and forensic analysis. In the process of design, loads and materials must be assumed. In contrast, when investigating a failure, it is possible to know the materials and structural configuration and the loads applied at the time of collapse. The necessary modeling is thus very different from the design process. Nonlinear models provide a powerful tool for forensic investigation, if they are used correctly. Many examples have been published in the American Society of Civil Engineers Journal of Performance of Constructed Facilities (ASCE JPCF) or presented at the eight ASCE Forensics Congresses, held approximately every three years since 1997. This overview paper will review case studies of modeling applied to forensic investigations and examine some of the issues associated with the use of such models. [ABSTRACT FROM AUTHOR]

i b Our Task Group 5.1 (TG5.1) "Forensic Structural Engineering" (FSE) is part of Commission 5 "Existing Structure" of IABSE Technical Committees. B I Please introduce yourselves to our SEI readers. i b A personal introduction by Karel Terwel My name is Karel Terwel, and I am from the Netherlands. [Extracted from the article]

The structural fire analysis of bridges is crucial for ensuring transportation infrastructure safety since bridges, due to their unique characteristics and exposure to environmental hazards, are particularly susceptible to fire-induced damage. Despite this vulnerability, there is a lack of both experimental research and design guidelines for ensuring fire safety in bridges. This underscores the importance of studying actual bridge fire incidents. This article presents a comprehensive examination of the numerical and experimental investigations carried out to evaluate the structural condition of a composite box-girder bridge located in Valencia, Spain, following a significant fire incident. In addition, the paper details the repair works carried out to fully restore the operational capacity of the bridge, along with the key lessons learnt from the incident. Therefore, the article highlights the vital synergy between advanced numerical models and experimental investigations to strengthen rehabilitation action plans and gain valuable insights for making informed decisions regarding post-fire structural integrity. By doing so, the study enhances understanding of bridge safety under fire and provides actionable recommendations for researchers, practitioners, and transportation authorities. • There is a lack of guidelines on the assessment of bridges vis-à-vis fire hazards. • Effects of a real fire on a bridge examined with numerical and experimental methods. • Repair works and lessons learned from the incident are detailed. • Synergies of numerical models and experiments strengthens rehabilitation planning. • Fire safety insights and informed decision-making for bridge resilience enhanced. [ABSTRACT FROM AUTHOR]

A fatal collision involving a pedestrian struck by a public train at a rail station located in a major U.S. metropolitan city was investigated. The train was equipped with an event data recorder that recorded valuable empirical data related to the collision, such as the train speed, braking, and acceleration inputs. However, the original digital version of the data was not available to analyze, and only a single screenshot of the data in an analog graph format was available. The subject train was equipped with multiple video cameras at various vantage points that recorded video footage of the collision. Using the process of “matchmoving” — and with the assistance of three-dimensional LiDAR scanning of the station and train — video footage was analyzed to spatially determine the location of the train in three-dimensional space. The process of matchmoving is an established scientific process used to calibrate a virtual camera to “match” the movement and optic properties of the real-world camera that captured the video. Further analysis was performed to determine the train’s kinematics (such as its speed and deceleration rates) leading up to the collision. The accuracy of the matchmoving analysis was then verified with the available event data. [ABSTRACT FROM AUTHOR]

After a worker was found fatally pinned between the top rail of a scissor lift and an overhead beam, rescue attempts were frustrated by unresponsive lift controls. In the investigation of this fatal accident, certain lift controls did not function or functioned intermittently. The intermittent nature of the malfunction indicated that the evidence was sensitive — likely to be disturbed if the device was disassembled using typical destructive techniques. Therefore, nondestructive techniques were required. This study discusses how X-ray imaging, computed tomography (CT), electrical testing, and engineering analysis of the lift and control system were used to investigate the causes and contributing factors of this fatal accident without disturbing sensitive evidence. [ABSTRACT FROM AUTHOR]

An analysis of an industrial lathe accident is presented in this paper. During operation, the rotating chuck lost its grip upon the cylindrical workpiece. The detached workpiece impacted the inside of the lathe cabinet, rebounded, struck the composite viewing window, and penetrated it. While observing the machining process through the window, the machinist was struck in the chest by the workpiece. He fell backward, suffering a severe traumatic brain injury when the back of his head impacted the concrete floor. The forensic analysis incorporated an event reconstruction to include an estimate of the ejection angle, velocity, and kinetic energy of the workpiece, the impact energy capacity of the window, and a failure analysis of the window and its frame. A kinetic energy analysis was performed by destructive testing of door/window replicas and high-speed videography. Impact testing of exemplar workpieces against alternative design highly impact-resistant windows was also performed [ABSTRACT FROM AUTHOR]

Structural fires globally have a catastrophic impact on loss of life, property damage, and socioeconomic factors. Forensic scientists, engineers, and/or fire investigators — often working together as fire investigation practitioners — are commonly tasked with determining both the area of fire origin and its cause. During the course of a fire investigation, a fire investigation practitioner may implement an origin determination methodology termed “arc mapping” or an “arc survey.” The correct application of an arc survey as a fire origin determination method is dependent on the fire investigation practitioner’s ability to distinguish and characterize features observed on post-fire damage electrical wiring and equipment. Experiments were conducted to generate a dataset of post-fire damaged electrical conductor artifacts. Generated artifacts were visually examined, compared, and characterized by X-ray examination. The research results produced a validated, novel, non-destructive methodology for utilizing X-ray imagery to reliably distinguish and characterize electrical conductor damage features for forensic investigations. [ABSTRACT FROM AUTHOR]

Forensic engineering analyses (FEA) of electrical shock incidents are challenging because many factors need to be considered to understand how and why the incident happened. The goal is to determine how and why the victim’s body became part of an electrical circuit that caused the shock injury. To do this, the engineer needs to determine, if possible, all of the connected portions that combined to make the complete circuit at the time of the shock, including the energized and non-energized conductors. Then, failures (defects) of components and violations from standards by parties involved with manufacturing, installing, inspecting, operating, and servicing the electrical circuits/systems involved need to be determined and their relation to the cause (failure-modes) evaluated1 . There will often be multiple circuits in the vicinity of the shock victim, some of which are pertinent to the shock and others that are not. These circuits need to be analyzed and non-pertinent circuits ruled out. When the pertinent circuit is determined, all the conductive elements and connections that form the (often three-dimensional) circuit should be identified. This includes service conductors, branch conductors, cords, portable devices, victims with their specific circumstances and conditions, their clothes, any moisture, tools, vehicles, and nearby materials, such as soil and vegetation. This paper outlines the scientific methodology and tools, logical decision analyses, and procedures for performing a shock analysis and provides specific examples based on actual investigations. [ABSTRACT FROM AUTHOR]

During their course of work, forensic engineers and electricians may apply electrical engineering and scientific principles to forensic investigations by performing electrical surveys and electrical fault evaluations. When undertaking a fire investigation, an investigator may implement a similar electrical fault methodology called “arc mapping” or more recently termed an “arc survey.” The correct application of either of these methodologies is dependent, in part, on the forensic investigator’s ability to distinguish features observed on damaged electrical wiring and equipment. Experiments were conducted to generate a post-fire damaged electrical artifact dataset for this engineering analysis. Generated artifacts of arc melting, fire melting, and mechanical damage features were examined, measured, and quantified by applying metallurgical analyses, such as visual examination, measurement, light microscopy, SEM/EDS, X-ray, and/or metallographic examination. The results produced a novel proof of concept method of quantifying and reliably identifying electrical conductor damage features for forensic electrical fault (short circuit) and/or arc survey evaluations. [ABSTRACT FROM AUTHOR]

Four students had staggered departures from their electrically heated third-floor shared residence apartment to travel home for the winter holiday break. Two pipe bursts and two frozen toilets were discovered a week after the last resident had left. The property management group gathered scene evidence and analyzed the cause of the water escape. The investigation revealed that some electric heaters had been turned off, and some bedroom and living room windows were open. A forensic engineering analysis was conducted to qualitatively determine the effects of heater disengagement and open window positions on the apartment temperature drop and to estimate the likely start date of sub-zero Celsius conditions. Heat flow and balance equations for different sets of factors were used to quantitatively assess the instantaneous heat flow trends as the basis for understanding whether certain students carried more burden of liability. The analysis revealed that the open windows were the dominant factor for the freeze-up condition development that led to the bursts. [ABSTRACT FROM AUTHOR]

A car flipping device is a special effects aid used to flip cars in the production of movies and television shows. The device uses a pivoting arm that moves under the stroke of a cylinder powered by compressed nitrogen. In a trial run of the device, the cylinder's piston broke through the cylinder cap. A kinematic analysis developed a parametric mathematical model of the motion of the cylinder arm and piston, which formed the basis for a finite difference analysis to determine the speed of the cylinder's piston at the end of its stroke. Metallurgical testing was conducted on the broken cylinder to determine the stress-strain characteristics, impact resistance, and Scanning Electron Microscopy (SEM) used to examine the fracture surface. The analysis determined that the kinetic energy of the piston was adequate to cause yielding of the cylinder but not rupture. Continued usage degraded the impact resistance available until rupture occurred. [ABSTRACT FROM AUTHOR]

Following the explosion of a natural gas pipeline that resulted in extensive property damage, personal injury, and loss of life, a forensic engineering investigation was performed to determine factors that significantly contributed to the failure. Metallurgical analysis of the failure region resulted in the conclusion that the pipeline rupture was caused by hydrogen embrittlement acting on hard spots created during manufacturing. The next phase of this investigation involved root cause analysis of factors contributing to the pipeline rupture as well as evaluation of missed risk-reduction opportunities of the nondestructive analyses employed. It was ultimately determined that hydrogen embrittlement, caused by improper operation and maintenance procedures, resulted in an overabundance of hydrogen from excessive cathodic protection. Additionally, excessive operating pressure exceeded the resulting degraded ultimate capacity of the pipeline, which then manifested in the rupture of the natural gas pipeline and the ensuing explosion. It is recommended that operators exercise due diligence by considering the age of a pipeline when determining appropriate operating, monitoring, and maintenance procedures. [ABSTRACT FROM AUTHOR]

When borax gets wet, it clumps. In this case, 76,000 pounds of previously wetted borax clumped on the inside of a rail car. The unbalanced load caused the rail car to fall on a yard worker, killing him. Tracking meteorological conditions in transit from Turkey to a port in Deleware, truck transit to a warehouse, handling at the warehouse, and rail transit to an interim transfer station was key to developing the origin and cause for the rail car derailing. There was evidence that clumping had rendered the product unusable by the end-user. However, this event occurred at the interim transfer station where the rail car product was transferred to trucks. This paper describes the process of determining how and where the borax absorbed moisture and shows physics that determined derailing was the result of an unbalanced load. This demonstrates the cause and effect of this event. [ABSTRACT FROM AUTHOR]

Stand-up forklift collisions with storage racks are a known hazard in the material-handling industry. When the height of the first rack beam from the floor is close to or above the height of the forklift's operator compartment -- and is at a height that is lower than the forklift's overhead guard -- the rack beam can intrude into the forklift's operator compartment. These collisions are typically referred to as "horizontal intrusion incidents," also known as "underride" incidents. When the forklift is not equipped with horizontal intrusion guarding, these occurrences often lead to serious (if not fatal) injuries. This paper presents physical testing and analysis of one major forklift manufacturer's accident database records, which show rear-mounted posts are effective guards in reducing or preventing the consequences of horizontal intrusion incidents. Further, this paper shows these rear post guards met and exceeded design requirements of the material-handling industry standards. [ABSTRACT FROM AUTHOR]

The proliferation of propane-fueled food trucks and concession trailers over the last decade has led to a fast-growing industry. As with many nascent industries, accidents accompany the surge in growth, and the food truck industry is no exception. Numerous propane-related fires, flash fires, and explosions have resulted in property damage, business interruption, injury, and death. Conducting a proper investigation of a food truck incident is essential in determining the origin/cause and ultimately assigning liability and preventing recurrences. This paper discusses the food truck industry as well as the design, construction, and layout of the trucks. It provides an overview of the gas systems installed in the vehicles -- from the cylinder or tank to the appliances, properties of propane, and relevant codes and standards applicable to food trucks that utilize propane. Finally, an outline of the proper methodology to use when investigating a food truck incident is provided, and a food truck explosion case study is presented. [ABSTRACT FROM AUTHOR]

The foot platform of a climbing treestand fractured while a user was standing on it in the process of securing his harness to a tree. Analysis of the frame's fracture surface revealed a manufacturing defect in the form of a ¼-inch diameter hole next to the fracture area, likely created during the welding process. To prove that this defect was the proximate cause of the treestand's failure (under reasonably expected and foreseeable use conditions), a series of tests on exemplar treestands as well as finite element analysis were performed. It was concluded that the defect reduced the fracture toughness of the treestand by 40%. In addition, it was found that the manufacturer failed to account for additional stress caused by dynamic loading experienced during normal use. The authors opined that both the reduced strength and the omission of dynamic loading in the design resulted in the treestand's frame failure. Appropriateness of the manufacturer's reliance on users always wearing their full body harness is also discussed. This paper examines the contribution of the drilled hole to the integrity and suitability of the ASTM-required Factor of Safety (FOS) of 2. [ABSTRACT FROM AUTHOR]

Infrastructure monitoring can facilitate the evaluation of capacity and functionality loss and therefore provide valuable data and evidence for reliable, lifetime and automated risk assessments. Terrestrial monitoring systems can provide information about assets and their condition. Yet, they fall short of engineering requirements related to the history of the asset loading, deterioration and potential damage, which is of paramount importance in risk-based decision-making by infrastructure operators. This capability gap can be filled by Persistent Scatterer Interferometry (PSI) Monitoring in conjunction with engineering forensics and judgment. This paper puts forward this hybrid approach to assess the structural condition of a landmark bridge by coupling advanced Differential SAR Tomography (D-TomoSAR) techniques with an adaptive deformation model, environmental measurements and engineering evidence and evaluations. A dataset of 360 Sentinel A &B images covering the period between 10/2014 and 2/2020 and temperature records to account for seasonal deformation were deployed. Displacement products, such as the development of annual displacement and time series were calculated demonstrating a strong correlation with temperature variation and resulting deformations of the asset. The spatiotemporally evolving deformation trends of the bridge superstructure were derived, and vulnerable deck locations were identified on the basis of engineering forensics, judgment and progressive displacements calculated from the D-TomoSAR technique. The vertical displacement profile at the critical deck location was developed reaching a displacement velocity of 1.8 mm/year and potential deterioration issues are manifested as potential causes of the observed geometric alterations. Based on the D-TomoSAR results matched with engineering evidence and on-site visual inspections and judgment, this study contributed to the decision-making process. This research is a pilot showcase of D-TomoSAR for the bridge monitoring, not only providing mm-level quantitative measurements of the bridge in a 6-year observation span using medium resolution Sentinel-1 SAR images alone but also indirectly identifying potential structural defects in the north section of the bridge. This research is a primer example of how we can deploy diverse evidence to facilitate targeted adaptation measures and prioritize restoration strategies to facilitate asset owners in better decision making. [ABSTRACT FROM AUTHOR]

This paper will present the results of a case study carried out with the students of Forensic Engineering at the University of Criminal Investigation and Police Studies in Belgrade for two consecutive academic years. The goal of the study was to determine if and to what extent the receptive vocabulary size acquired during previous education will influence the acquision of semi-technical vocabulary covered by two one-semester English courses. The data have been gathered using both a questionnare and relevant tests. The statistical processing of data has enabled better intepretation of the results obtained. [ABSTRACT FROM AUTHOR]

The interest in producing biodegradable polymers by chemical treatment, microorganisms and enzymes has increased to make it easier to dispose after the end of its use without harming the environment. Biodegradable polymers reported a set of issues on their way to becoming effective materials. In this article, biodegradable polymers, treatment, composites, blending and modeling are studied. Environmental fate and assessment of biodegradable polymers are discussed in detail. The forensic engineering of biodegradable polymers and understanding of the relationships between their structure, properties, and behavior before, during, and after practical applications are investigated. [ABSTRACT FROM AUTHOR]

An expressway interchange bridge was completed in 2016 in China. In 2019, disease phenomenon, including pier inclination, excessive support slip, and expansion joint damage, were found in the ramp bridge, which influenced the bridge safety and operation. This article conducts a forensic engineering field investigation and uses finite element modeling, revealing the process of disease occurrence according to the displacement cooperation relations in the pier–support–girder region. This research concludes that the main technical causes of the bridge's disease include: (1) eccentric compression on the pier during construction and operation due to an improper design change and the asynchronous construction process; (2) asymmetric foundation settlement caused by the temporary load during construction and the weight of the filling soil during operation. Finally, the ethical factors leading to the disease are summarized based on technical causes, which can alert professional engineers to problems that should be considered in the design and construction of high-pier bridges with a soft foundation. [ABSTRACT FROM AUTHOR]