Journal of the National Academy of Forensic Engineers

Investigating Effects of Imperfections on Aluminum Stepladder Using Finite Element Analysis

John Thomazin — 2026-07-11

Ladders are a valuable tool, but they can also be dangerous. In 2020, ladder-related falls resulted in more than 100 fatalities and thousands of injuries, particularly in the installation, maintenance, and repair industries [1]. The ANSI A14.2 standard governs the safe construction, design, testing, and use of portable metal ladders, outlining requirements for ladder rung spacing, connections, and angle of inclination. While 15 different load tests are performed to ensure a ladder meets the standard, it’s important to note that these tests use statistical tolerances and represent pass/fail criteria. Altering the cross-section of a shape can impact its stiffness, and imperfections can affect a structure’s collapse. Understanding the testing limitations is crucial. To reduce ladder-related injuries and fatalities, imperfection-sensitive ladders can be detected, evaluated, and identified using 3D modeling and nonlinear finite element analysis (FEA). This paper presents a technique for using linear-elastic buckling analysis to identify potential failure modes. It is followed by nonlinear static analysis with material plasticity to detect significant decreases in strength when dents or other imperfections are included in the geometry or when the applied load directions are changed.

Barrel Failure in an Over and Under Shotgun

Stephen Batzer — 2026-07-11

A 12-gauge over-and-under shotgun experienced a rupture in its lower barrel when firing standard factory ammunition. This incident marked the shotgun’s first use in the field, as it had only been test-fired at the factory with regular-pressure shells (not proof loads) prior to this event. The barrel steel split axially ahead of the reinforced chamber, under the polymer fore-end, causing hot gases and plastic debris to violently strike the shooter’s left hand, resulting in serious injury. A detailed metallurgical and geometric evaluation of the affected barrel was conducted at an independent third-party laboratory. Chemical analysis confirmed the steel matched SAE 1045 alloy with appropriate hardness for the barrel’s intended thickness. Performance testing on a new, identical shotgun using intentionally overloaded shells was also carried out, despite the spent hulls from the incident showing no signs of excessive pressure. The assessment uncovered a distinct manufacturing flaw in the lower barrel, creating a localized weak spot in the barrel wall.

The The Importance of Human Perception in Incident Reconstruction and Potential for Misleading Interactive Reconstructions

Henry Mowry — 2026-07-11

A common and key component of forensic engineering and incident investigations is the “reconstruction” component. Reconstructions allow the investigator to build and analyze the incident based upon objective information such as video cameras (including dash cameras, surveillance cameras, and more), post-incident photographs (such as from first responders, eyewitnesses, etc.), physical data (including evidence such as skid marks in a roadway, damage patterns to involved objects such as vehicles, buildings, etc.), and even physical injuries. As reconstructions, software, and technology advance over time, “interactive” reconstructions are becoming increasingly beneficial and prevalent in investigations, allowing the reconstructionist to control and adjust the reconstruction as it is shown. Interactive reconstructions allow the controlling individual to move cameras, start and stop the reconstruction, adjust parameters or variables, and allow analysis of the incident from static and omniscient perspectives. However, such interactive reconstructions can also be misleading. This paper will discuss the often disregarded or misrepresented portion of a reconstruction — what the individual(s) in question “saw” or “perceived” during the incident — as well as demonstrate the potential for misleading interactive reconstructions.

Wind Damage vs. Storm Surge Damage: Case Studies from Hurricane Helene

Manuel Matus — 2026-07-11

Between 1980 and 2024, natural hazards have resulted in approximately $2.9 trillion in economic losses across the United States. Tropical cyclones represent the most damaging hazard type, accounting for approximately 53% of total losses, and are classified as multi-hazard events due to the combined impacts of wind loading and storm surge inundation. In the contiguous United States, coastal regions comprise only 10% of the total land area yet contain approximately 40% of the population, making these communities particularly susceptible to damage from hurricane-induced wind as well as storm surge-related forces. Following major events, post-disaster damage assessments conducted by federal agencies (such as FEMA) and by private-sector entities (including insurance carriers) are tasked with distinguishing between wind-related and storm surge-related damage. This forensic differentiation is critical for structural failure analysis, accurate insurance claims adjudication, and equitable allocation of recovery resources. Misattribution can lead to substantial disputes and financial discrepancies. This paper presents a case study for both pre-event vulnerability assessments and post-event forensic evaluations aimed at identifying and differentiating wind-induced versus storm surge-induced damage to residential buildings. The methodology described in this document integrates civil engineering principles and forensic investigation techniques to provide guidance for improving damage attribution accuracy and post-disaster decision-making.

Forensic Engineering Analysis of Roadway Geometry and Traffic Control

Tim McClure — 2026-07-11

When evaluating evidence for causative factors contributing to a motor vehicle collision, consideration should be given to roadway geometric or traffic control factors. Roadway geometry, clear zone, safety features, visibility obstructions, and traffic control devices and their placement may influence drivers’ behavior. Are the roadways involved properly designed and signed? The geometric design and traffic control requirements for special circumstances, such as highway construction zones, mixed-use paths, railway crossings, or low traffic volumes, may also present the potential for roadway issues. An evaluation of these potential contributing factors can open a Pandora’s box of opportunities for errors when an improper engineering analysis follows. This paper explores the topics that guide proper engineering analysis of roadway geometry and traffic control, including determining which design standards, policies, or guidelines apply and the proper application of the semantics in these documents. Additionally, this paper addresses recommendations contained in research concepts or reports versus requirements for the designer, the constructor, or the roadway owner. The discussion includes examples from past cases addressing the topics presented, providing a systematic approach to evaluating permanent or temporary roadway geometric or traffic control design for factors contributing to a collision event.

Beyond the Building Code — Compliance and Forensic Failure Analysis of Retaining Walls

Brian Eubanks — 2026-07-11

Retaining walls are structural walls that serve to laterally restrain earth at a desired elevation in order to shape the topography of a site by managing slopes and creating usable spaces for development and construction of the built environment. Common types of retaining walls include mass/gravity walls, cantilevered walls, pile walls, and mechanically stabilized earth (MSE) walls. The design and construction of such walls are not well covered in the International Residential Code (IRC) and/or the International Building Code (IBC). As structural elements subjected to applied soil forces, retaining walls cross engineering disciplines, and a successful design often requires careful coordination between geotechnical engineers and structural engineers. In addition, successful construction often requires field verification of expected geotechnical parameters and construction oversight to ensure compliance with design specifications. This paper will explore the different stability checks (e.g., internal stability, local stability, and global stability), as well as different factors of safety, required for the proper design of a retaining wall. In addition, it will use real-world case studies to explore failures of various retaining walls, highlighting differences between compliance analysis and forensic failure analysis to identify the root cause of the failure and the responsible party.