Abstract:Globally, earthmoving equipment is significant for the mine production system to ensure continuous flow of ground. This equipment is capital intensive and mining organizations face challenges in reducing operational cost, capital cost and maintaining high production capacities. As such, high equipment availability, safety of personnel and equipment, maintainability and controllable reliability become an important aspect. Several maintenance strategies have been developed, backed up by various models and frameworks to help minimize equipment failure as unplanned equipment downtime has a triple cost implication on the organization. These costs being, production cost in not meeting the output target, maintenance cost; the more breakdowns experienced, the more parts will be required to repair broken down equipment as well as maintenance labor cost which usually arises from unplanned work. Finally, fixed cost associated with mining operations such as power. To ensure that equipment downtime is minimized, routine equipment maintenance has been given priority, however, tyre performance has received less attention in comparison with other equipment components such as engines, transmissions, gearboxes and final drives. Tyres are one of the major cost drivers in a mining operation and at the same time a severe safety hazard due to their mass and stored energy. ABC Mine (not the real name) experienced a number of premature failure of Dump Truck tyres during the period January 2019 to April 2020 and the main cause of failure was not adequately established, though the failure modes data was collected and recorded through the Planning Section. Further, the Mine Management attributed these failures to poor operator practices and the harsh environmental conditions at the Mine. The aim of this study is therefore, to investigate the actual cause of the numerous tyre failures at ABC Mine. Reliability and Maintainability characteristics; Meantime Between Failure (MTBF) and Meantime To Repair (MTTR) associated with tyre performance were reviewed in order to show the effect of tyre downtime on productivity. Data collection was through document review from planning office, Vehicle Information Management System (VIMS), participant observation and through calculation of operating parameters such as TKPH. Tables and graphs were used to present data trends and their characteristics. The study concluded that, the numerous premature failure of the Truck tyres at ABC Mine during the stated period was as a result of the wrong specification of the tyre. The TKPH of the tyre used was lower than the real site TKPH, hence, failing the condition: Tyre TKPH ≥ Real Site TKPH. Though the maintenance side of the tyre management system and the load and haul management system contributed to the low tyre life due to their ineffectiveness, TKPH of the tyre had the greatest impact on tyre life.
Keywords:Tonne Kilometer Per Hour (TKPH), Pyrolysis, Lateral Acceleration, Tyre, Payload, Scuffing, Maintenance.

Title:Investigating the Cause of Premature Tyre Failure of Open Pit Mine Dump Trucks: A Case of ABC Mine, Northeast Africa
Author:Dr. Dyson Galatia, PhD
ISSN 2394-7349
International Journal of Novel Research in Engineering and Science
Novelty Journals

Abstract:The use of Shape Memory Alloys (SMA) as an actuator constitutes a major challenge in terms of their application in innovative products. The present work deals with the torsional characteristics and the modeling of NiTiCu SMA bars to ensure their mechanical performance as torsional actuator. The SMA bars was tested under quasi-static torsional loading and torsional fatigue conditions and their behavior was described using a torsional model based on the modification of Liang-Rogers constitutive relation. Further to torsional mechanical tests, a comprehensive experimental investigation on the torsional fatigue behavior of SMA bars, under the application of given external loading moment, with the temperature to vary from 25^oC (well below M_f) to 100^oC (over A_s) is provided.
Keywords:Shape Memory Alloys, Smart actuator, Smart materials, SMA fatigue, SMA driven mechanism.

Title:On the Torsional fatigue of NiTiCu SMA bars. Experimental results and modeling approach
Author:A. Kokkinos, V. Kostopoulos
ISSN 2394-7349
International Journal of Novel Research in Engineering and Science
Novelty Journals

Abstract: Surface roughness increases the pressure drop of the flow in a large pipe, as it has been established in literature, however, little is known about pipes with smaller diameters. This work studies the effect of the surface roughness on the pressure drop in pipes with smaller diameters. The pipe considered has ID of 2.3mm, OD of 5mm and a length of 135mm. The numerical analysis was performed using the ANSYS FLUENT software and the roughness on the pipe was modelled as a sphere with a size of 1μm. Two different cases were considered for the analysis; when the pipe was smooth and when the pipe was rough. The results showed there was a higher pressure drop in the rough pipe than in the smooth pipe. In addition, the size of the roughness was then increased for 1,5,10,50,100 and 200 microns, and the result shows that as the roughness size increased the pressure drop also increases.
Keywords: ANSYS, CFD, FLUENT, laminar flow, pipe, Pressure drop, surface roughness, small diameter.

Title: EFFECT OF INNER SURFACE ROUGHNESS ON PRESSURE DROP IN A SMALL DIAMETER PIPE
Author: Goziya W. Dzarma, Adekola B. Adeyemi, Abdulmalik A. Taj-Liad
ISSN 2394-7349
International Journal of Novel Research in Engineering and Science
Novelty Journals