Papers by Keyword: Structural Integrity

Abstract: This paper presents the constructive and functional optimization of a fuel tank designed for the supply system of a spark ignition engine. The study focuses on the use of high-density polyethylene (HDPE) as a lightweight and durable material, aiming to improve fuel efficiency and safety. The 3D model of the tank was developed using CATIA V5. Numerical simulations were performed in ANSYS to evaluate the structural behavior of the tank under pressure and vacuum conditions. Although not part of the formal validation process, these simulations provide valuable insights for improving the tank geometry. The results demonstrate the potential of plastic fuel tanks to meet operational requirements.

Abstract: This paper presents the design, modeling, and analysis of a solar-powered geared tricycle intended to provide an efficient, eco-friendly alternative for personal mobility. The work integrates mechanical, electrical, and structural engineering principles to ensure dynamic performance, structural integrity, and overall stability under varying operational conditions. A lightweight chassis, optimized using finite element analysis (FEA), is designed to withstand dynamic loads while maintaining low energy consumption. The drive system incorporates a multi-speed gear mechanism coupled with a high-efficiency brushless DC motor powered by a photovoltaic (PV) array and battery storage system, enabling hybrid propulsion. The dynamic behaviour of the tricycle, including acceleration, turning, and braking responses, is simulated using MATLAB/Simulink to evaluate performance across urban terrains. Stability is assessed through center-of-gravity analysis, roll-over threshold calculations, and tilt angle monitoring to prevent tipping during sharp maneuvers. The integration of solar technology not only extends operational range but also reduces environmental impact, making the design suitable for sustainable transportation in developing and urban regions.

Abstract: Penstock pipelines in hydroelectric power plants are critical components whose structural integrity is paramount for reliable operation. However, they are subjected to severe operational conditions generating complex stresses, favoring low-cycle fatigue crack initiation, particularly at critical weld zones. This is exacerbated by anomalous operational cycles like repetitive emptying and filling. This study presents a comprehensive methodology combining X-ray Diffraction (XRD) with other Non-Destructive Testing (NDT) techniques to assess residual stresses and their impact on pipeline integrity. XRD quantifies net stress under empty pipeline conditions, determining superposition between intrinsic residual stresses (manufacturing, welding, service-induced) and non-hydrostatic loads (self-weight, geomechanical forces). Diffraction pattern analysis yields crucial stress distribution data [1-5], identifying critical concentration zones prone to fatigue [6-10]. Complementary NDT techniques reveal morphological discontinuities influencing material mechanical behavior. Correlating XRD and morphological findings establishes cause-effect relationships between structural state and measured residual stresses. This integrated methodology offers significant predictive maintenance advantages, providing quantitative assessment of current pipeline state and projecting future performance.

Abstract: This study investigates the effectiveness of a commercially available two-part fiberglass patching kit for repairing steel plates with cracks of varying sizes. The kit, produced by DuraPower Product Inc., includes a fiberglass patch, resin, and an activator, which serve as the adhesive for the repair. Four steel plates were tested: one without a crack and three with small (5 mm), medium (13 mm), and large (20 mm) cracks machined at the center. The repair process involved applying a fiberglass patch to each plate, and Non-Destructive Evaluation (NDE) using PZT-SLDV Lamb waves employed to assess the repaired specimens. The NDE results showed that the patching material significantly influenced wave energy transmission, with wave energy being more confined within the patch on the repaired surfaces. The study demonstrated that the repair process was effective in restoring the structural integrity of plates with varying crack sizes, successfully addressing defects of different lengths, and achieving good adhesion with minimal air bubble formation. This research provides valuable insights into the real-world applicability of the patching kit for repairing cracked steel surfaces.

Abstract: This study analyzes the impact of high temperatures on the physico-chemical properties of concrete, highlighting a marked decrease in strength and material integrity. Among the mechanical non-destructive testing methods, the rebound hammer technique was selected for its accessibility, speed, and capacity to deliver preliminary on-site results. Field data obtained at fire-damaged sites reflect the extent of material degradation and enable the identification of critical heat-affected zones and potential fire origin points. By comparing the strength of concrete in damaged versus intact areas, the most severely affected zones can be identified.

Abstract: This paper presents findings from an ongoing study on the condition assessment and numerical modelling of a reinforced concrete bridge B0140 along C46 in Ongwediva, Namibia. An analysis of bending moments, stresses and deflections of the bridge under the prevailing abnormal loads on the bridge was undertaken using Autodesk Robot Structural Analysis Professional (RSAP) software. The aim of this study was to develop a numerical model of bridge B0140. The objectives of this study were twofold, namely, to use the developed model to predict bending moments, stresses and deflection of the bridge structural elements and to evaluate the adequacy of the existing reinforcement under the prevailing environmental conditions and abnormal loads according to BS 5400 requirements. Information pertaining to the geometry of the bridge and the mechanical properties of the materials used for construction were obtained from “as-built” engineering drawings from the Roads Authority (RA) of Namibia, physical measurements and non-destructive testing in situ. Preliminary results from the developed model indicate that the bending moments, stresses and deflections of the bridge under the prevailing environmental conditions and abnormal loads are satisfactory. The developed model, however, needs further refinement, calibration and validation to improve its accuracy.

Abstract: This study investigates the impact of high temperatures on the structural and physico-chemical properties of concrete, emphasizing the degradation of material strength under fire exposure. Through a review of reference data, it was confirmed that elevated temperatures significantly reduce concrete strength, potentially leading to structural failure. The rebound hammer method, a mechanical non-destructive testing technique, was selected for on-site evaluation due to its accessibility, speed, and ability to provide immediate preliminary results. Field measurements conducted at fire-affected sites allowed for the identification of temperature zones and heat flow directions based on variations in concrete strength. Comparative analysis between intact and damaged areas enabled the identification of critically affected zones and the estimation of structural degradation. The study demonstrates that using the Schmidt hammer, with proper calibration and error consideration, provides reliable data for determining the origin of the fire and for making informed decisions on structural repair or reinforcement.

Abstract: Welding operations are known for high safety risk which requires urgent identification and prevention before they result in huge negative impacts on the nations’ gross domestic product, organizations, workers and the environment. This research aimed at developing a human factor engineering model that support loss prevention in welding industry by assessing the impact of human factors on incident frequency and safety performance in Nigerian Oil and Gas industry. The study was carried out using coded skilled welders who had at least two years’ experience and above. Descriptive study design with structured questionnaire was used for data collection and Satistical Package for Social Sciences (SPSS) version 26 Structural equation modelling software for data analysis. The results revealed that Pearson’s correlation coefficient between human factors and safety performance were statistically significant with a p-values of -0.45, 0.72, -0.50, 0.77 and 0.32 for workplace, task, personal, organizational and design factors respectively. Pearson’s correlation coefficient between human factors and incident frequency and fatality rates were 0.64, -0.55, 0.71, -0.89, and -0.45 for workplace, task, personal, organizational and design factors respectively. The structural equation regression model showed that human factors and safety performance was statistically significant with a path coefficient of -0.733, 0.860, -0.615, 0.616 and 0.430 for personal, organizational, workplace, design and task factors respectively. The structural equation regression model showed that human factors and incident frequency was statistically significant with a path coefficient of 0.59, -0.79, 0.63, -0.60 and -0.31 for personal, organizational, workplace, design and task factors respectively.The research concluded that engineered human factors would lead to improved safety performance, structural integrity and reduction in incident frequency rate. The study recommended that national, international agencies, government, professional bodies and companies should focus on human factor engineering in delivering products with structural integrity, boost performance and reduce lost time injuries and occupational diseases.

Abstract: A construction building's structural integrity, material quality, workmanship, and conformity to design specifications were all assessed qualitatively. Potential problems like cracks, corrosion, or subpar construction techniques were found during the examination through visual inspections, material testing, and documentation analysis. Guidelines for upkeep, fixes, or structural improvements were offered to guarantee the building's longevity, security, and adherence to rules. The evaluation sought to improve the building's durability, functionality, and occupant safety while correcting any flaws to preserve structural integrity.

Abstract: Machine tool housing design is pivotal in optimizing manufacturing processes, focusing on functionality, ease of assembly, and alignment precision. Current materials face challenges in static, dynamic, and thermal behaviors, impacting machining quality. The properties of ultra high-performance concrete (UHPC) such as high strength, low porosity, and corrosion resistance make it ideal for machine tool applications, promising increased precision and efficiency while reducing material costs and labor. Its recyclability adds environmental benefits. Incorporating UHPC in machine tool structures, including hybrid materials like Carbon Fiber Reinforced Plastic (CFRP), achieves superior static, dynamic, and thermal stability. Experimental results demonstrate UHPC’s compressive strengths (17,000-22,000 psi), surpassing conventional materials, and its ability to enhance machine tool performance and sustainability. This research highlights UHPC as a transformative material for resilient, precise, and eco-friendly manufacturing solutions.