Journal of the National Academy of Forensic Engineers

Discerning Wind-Related Damage to Residential Roofs

Ziad Azzi, Krishna Sai Vutukuru, Manuel Matus — Sun, 04 Jan 2026 00:00:00 +0000

Hurricane season brings a significant rise in wind-related insurance claims, as powerful storms lead to property damage (particularly to roofs). Distinguishing between wind- and nonwind-related damage, as well as pre-existing issues with roofing components, is critical to ensuring fair, efficient, and timely resolutions. This study presents an in-depth analysis of wind-related damage to two common roof covering materials: asphalt composition shingles and clay/concrete tiles. A series of detailed studies coupled with data from field inspections is utilized to differentiate wind-induced damage to roofs from issues stemming from wear and tear, material aging, installation deficiencies, and simulated wind damage (among other environmental and mechanical factors). Damage patterns, damage location, and material behavior from field observations coupled with wind flow around bluff-bodies (such as residential structures) are examined to highlight how the unique properties of each roof (including its location, height, shape, and slope) influence its response to wind-induced pressures during extreme wind events. These insights enhance damage identification, including cause, origin, and duration of roof covering failures, as well as support informed decision-making for roof inspectors.

Inside 40 Years of Advances in Failure Analysis of Polymeric Composite Materials

Geoffrey Clarkson, Daniel P. Couture — Sun, 04 Jan 2026 00:00:00 +0000

Use of polymeric composite materials is becoming increasingly widespread. Diverse applications include fixed infrastructure, industrial chemical processing, power generation, and aeronautics. Engineers have codified design principles and manufacturing practices so they are accessible to practitioners with general engineering education. In almost all cases, when polymeric composites enter service, none of the design codes, approaches, or construction standards apply, and they cannot be used to determine Fitness For Service. When failures occur, approaches that are normally followed in investigation yield inconclusive results, which often creates a conclusion that: “There was an undetected manufacturing defect.” All polymeric composites are non-crystalline, non-linear viscoelastic materials, and their mechanical properties change continuously while in service. This paper describes how damage occurs in these materials, demonstrates how it can be detected, and provides a methodology for addressing these failures.

Analysis of a UTV Axle Fracture Associated with Rollover

Stephen Batzer — Sun, 04 Jan 2026 00:00:00 +0000

An analysis of the fracture mechanism of a rear axle shaft of an off-road side-by-side utility vehicle (UTV) is presented in this paper. Two minors were recreating; they were riding a UTV within the fenced confines of the family farm. While driving on a dirt trail at a substantial velocity, the UTV yawed hard to the left, just before the turn in the trail. The leading side passenger’s side tires dug into the soft soil, and the UTV overturned for three-quarters of a revolution. The belted driver was partially ejected during the overturn and fatally pinned underneath the vehicle’s tubular rollover protective structure. After the event, the vehicle could not be driven as the left rear axle was fractured nearest the inner race of the outboard constant velocity (CV) joint, and the wheel hub and disc brake system were damaged. The investigation answered the question: “Did the overturn cause the axle fracture, or did the axle fracture cause a braking action and initiate the overturn?”

Forensic Analysis of Construction Variances Associated with Cement Plaster (Stucco) Veneer Installed Over Wood Framing

Brian Eubanks, Garrett T. Ryan, Derek Patoskie — Sun, 04 Jan 2026 00:00:00 +0000

The International Residential Code (IRC) provides prescriptive specifications for the installation of cement plaster (stucco) veneer on wood framing. Since 2006, the IRC has also referenced ASTM C926 (Standard Specification for Application of Portland Cement-Based Plaster) and ASTM C1063 (Standard Specification for Installation of Lathing and Furring to Receive Interior and Exterior Portland Cement-Based Plaster) as applicable standards that provide additional specifications associated with the installation of cement plaster veneer. The IRC and the applicable code-referenced standards do not consider all available materials, designs, and/or methods of construction — nor do they consider possible alternatives or construction variances. Since there is more than one way to accomplish a goal, a forensic investigation should consider the intent and purpose of a specification (i.e., the desired performance) to determine whether an as-built alternative or construction variance is capable of accomplishing the same without adversely affecting a structure. This paper explores common construction alternatives and variances associated with the installation of cement plaster veneer (including control joints, attachment, thickness, and clearance) using methodologies for evaluating whether an alternative or variance can still achieve the intent and purpose of the specifications provided in the IRC and/or applicable code-referenced standards.

Unreliable at the Boundary: Analysis of Two Sub-Optimum Crossbow Trigger Designs

Stephen Batzer — Sun, 04 Jan 2026 00:00:00 +0000

It is a fundamental principle that any weapon activated by a trigger — whether a crossbow, pistol, rifle, or shotgun — should only fire when the safety is set to the FIRE position, and the trigger is pulled. This study examines two distinct crossbow trigger designs associated with injuries. In the first crossbow, the trigger safety can be unintentionally or intentionally moved to an “intermediate” position (a point on the edge between SAFE and FIRE). This setting creates uncertainty, leading to instances where the crossbow discharges unexpectedly, either during arrow handling or even after sitting idle with no user action. In the second crossbow design, if the bowstring is not drawn with enough force, the safety fails to fully lock in place, resulting in the sear providing inadequate support to the corresponding release component. This creates a hazardous situation, observed to cause unintended discharge and injury to the user without any trigger activation. In both cases, the injuries did not stem from deliberate misuse; instead, the archer was operating the crossbow in a reasonable way that slightly deviated from the manufacturer’s intent.

Beyond the Building Code: Expansive Soils

Brian Eubanks, Lauren Kelly, Rebecca Bowman, Joseph P. Roberts — Sun, 04 Jan 2026 00:00:00 +0000

As defined by ASTM, soils that are susceptible to significant volumetric changes from the addition and/or removal of external elements are deemed “expansive.” Expansive soils associated with clay soil compositions are predominantly encountered throughout the central portion of the United States as well as portions of the southeast and west regions. Although it is not well documented, expansive soils are also encountered adjacent to coal deposits throughout the Appalachian coal region in the eastern United States. Depending on the mineralogy, clay soils comprised of expansive minerals can bond with moisture, causing the volume of the soil to increase with the addition of moisture and decrease with the withdrawal of moisture. This paper will explore tools for identifying expansive soils and factors to consider in the design and construction of ground-supported structures to mitigate the risk of post-construction differential foundation movement caused by expansive soils. It will also explore consequences to ground-supported structures not adequately designed and/or constructed for expansive soils as well as potential remedial measures to address adverse foundation performance.