-
Research/Technical Note
Structural Performance of an Articulating Aluminum Stair System Under Variable Inclination Angles
Nikhilkumar Patel*
Issue:
Volume 11, Issue 5, October 2026
Pages:
104-112
Received:
12 August 2026
Accepted:
21 August 2026
Published:
9 September 2026
Abstract: Articulating stair systems provide temporary access across changing elevations by allowing the stair frame to rotate while the walking treads remain approximately level. The resulting structure is not geometrically fixed: deployment angle changes effective member length, load path, bending demand, and stability. This study develops an angle-aware structural verification framework for an 18-step, 36 in wide aluminum stair system and compares two documented finite-element design states at 55° and 30°. The baseline structure uses 6061-T6 aluminum and was evaluated in SAP2000 using the load framework and member resistance procedures documented in the source structural calculation package, including ASCE/SEI 7-16, the 2022 California Building Code, and the 2020 Aluminum Design Manual. The governing side beam/stringer combined demand-to-capacity ratio increased from 0.731 at 55° to 0.948 at 30°, corresponding to a 29.7% increase in critical utilization and a reduction in remaining unity margin from 26.9% to 5.2%. Decomposition of the interaction check showed that major-axis bending governed the change: the major bending demand-to-capacity contribution increased from 0.661 to 0.892, while major bending demand increased from 1.353 to 1.785 ft-kip. At the same time, the reported axial-compression capacity of the side member decreased from 1.756 to 0.673 kip because of the longer effective member length and associated buckling response in the shallow configuration. Tread-member utilization remained low, decreasing from 0.034 to 0.017. The results demonstrate that the shallow-angle configuration, rather than the steep-angle configuration, controls the baseline unbraced system. The scientific contribution is a configuration-dependent interpretation of articulating stair behavior in which inclination is treated as an explicit structural design variable. The proposed framework can be extended to full-angle parametric analysis, reinforced configurations, connection assessment, fatigue studies, and experimental validation.
Abstract: Articulating stair systems provide temporary access across changing elevations by allowing the stair frame to rotate while the walking treads remain approximately level. The resulting structure is not geometrically fixed: deployment angle changes effective member length, load path, bending demand, and stability. This study develops an angle-aware s...
Show More
-
Research Article
Low-Cost Laser Decapsulation of Wire-Bonded Memory Packages with Dual Thermal Gating for Forensic Data Preservation
George Lloyd*
Issue:
Volume 11, Issue 5, October 2026
Pages:
113-123
Received:
14 August 2026
Accepted:
24 August 2026
Published:
15 September 2026
Abstract: Chip-off examination remains the method of last resort in digital forensics, applied when a device is locked, damaged or non-responsive, and it is the only route to data on many embedded targets such as vehicle event recorders and dashcams. The dominant removal technique is thermal reflow at approximately 360°C, and this is destructive to the evidence it recovers: charge leakage from flash memory is Arrhenius in temperature, so two minutes at 250°C consumes retention equivalent to centuries of room-temperature storage. This work develops a lower-temperature alternative using a consumer-grade 455 nm diode laser costing a small fraction of industrial equipment, together with an open-source browser-based tool that predicts thermal behaviour and gates recipes against two independent safety limits: wire-bond intermetallic damage and charge-retention loss. A finite element campaign in COMSOL Multiphysics characterised an eMMC package under a six-pass recipe. Two structural findings emerged. The bond-plane bulk temperature proved independent of remaining encapsulant thickness, because in quasi-steady state all absorbed power crosses the bond plane at fixed loop height regardless of the cap above it, which places the entire pass-to-pass risk in the per-pulse transient. Resolving finite spot size rather than assuming a one-dimensional heat source changed the predicted bond temperature from 181 to 272°C, which would condemn the process, to 94 to 139°C, which clears it. The campaign also identified two compensating errors in the tool's own analytical gate, which was corrected against the simulation. A single bench measurement, of laser spot size, returned 0.08 mm and satisfied a criterion recorded in advance. The wider bench validation programme is specified in full but was not executed, so the thermal model retains unverified status and all thermal figures reported are predictions rather than measurements. The claim advanced is one of data preservation, which is independent of encryption because charge leakage flips physical cells regardless of their contents.
Abstract: Chip-off examination remains the method of last resort in digital forensics, applied when a device is locked, damaged or non-responsive, and it is the only route to data on many embedded targets such as vehicle event recorders and dashcams. The dominant removal technique is thermal reflow at approximately 360°C, and this is destructive to the evide...
Show More
-
Research Article
Modelling and Simulation for Engineering Design: A Case Study of Second Order Differential Equations
Issue:
Volume 11, Issue 5, October 2026
Pages:
124-131
Received:
4 April 2026
Accepted:
14 April 2026
Published:
22 September 2026
DOI:
10.11648/j.ajmie.20261105.13
Downloads:
Views:
Abstract: This study investigates the application of second-order differential equations in the modelling and simulation of engineering systems, with a mass–spring system adopted as a representative case study for vibration-based design problems. The aim is to demonstrate how analytical and numerical approaches can be integrated to accurately predict system dynamics and support engineering design decisions. The governing equations are derived from Newton’s second law and solved analytically using characteristic equation methods, while numerical solutions are obtained using the fourth-order Runge–Kutta technique. Key system parameters, including mass, damping coefficient, and spring stiffness, are defined and used to simulate system response under dynamic conditions. The results show strong agreement between analytical and numerical solutions, validating the accuracy of the computational approach. Furthermore, the simulations reveal that system performance is highly sensitive to damping and stiffness variations, which directly influence oscillation amplitude, settling time, and stability. The findings demonstrate that second-order differential equation models provide a robust framework for predicting system behaviour and optimizing engineering design. It is concluded that integrating modelling and simulation techniques into computer-aided design (CAD) environments can significantly enhance design efficiency and performance evaluation. The study recommends the incorporation of advanced simulation-driven tools and intelligent control strategies to further improve the reliability and adaptability of engineering systems.
Abstract: This study investigates the application of second-order differential equations in the modelling and simulation of engineering systems, with a mass–spring system adopted as a representative case study for vibration-based design problems. The aim is to demonstrate how analytical and numerical approaches can be integrated to accurately predict system ...
Show More
