Research Article
Dynamic Analysis of the Influence of Railway Vehicle Speed on Passenger Ride Comfort When Wheels Undergo Polygonization Defects
Issue:
Volume 13, Issue 2, April 2025
Pages:
53-62
Received:
24 January 2025
Accepted:
11 February 2025
Published:
7 March 2025
DOI:
10.11648/j.ijmea.20251302.11
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Abstract: The railway transportation system is currently undergoing a significant expansion. As a result, train lines are upgraded, and the technical condition of the rail vehicles that use them is also taken into consideration. However, under certain circumstances, wheels on rail vehicles may sustain damage while in use. Then, depending on the kind and degree of flaws, the profile of the wheels is no longer circular but rather changes. The quality of a passenger's ride comfort is diminished when a rail vehicle with a damaged wheel is in operation. The research considered one type of railway wheel untrueness wheel polygonization and focused on the evaluation of ride comfort for passengers based on results obtained from numerical and dynamic analyses. Simulations and calculations were carried out in numerical and dynamic multibody software. The results show that with increasing vehicle speed, the ride index also increases, which means that at high speeds, the ride comfort will be diminished. Furthermore, it found that the orders of wheel polygonization have an effect on ride comfort. With the increasing order of polygonization, the ride index also increases. According to the findings, this study has a significant impact on the maintenance planning for wheels and rails as well as operation management.
Abstract: The railway transportation system is currently undergoing a significant expansion. As a result, train lines are upgraded, and the technical condition of the rail vehicles that use them is also taken into consideration. However, under certain circumstances, wheels on rail vehicles may sustain damage while in use. Then, depending on the kind and degr...
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Research Article
Performance, Emissions, and Suitability for Mass Production of an Updraft Biomass Gasifier Cookstove: An Experimental Study
Issue:
Volume 13, Issue 2, April 2025
Pages:
63-72
Received:
11 February 2025
Accepted:
26 February 2025
Published:
7 March 2025
DOI:
10.11648/j.ijmea.20251302.12
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Abstract: In Cameroon, renewable energy promotion is a key strategy for improving energy security and fostering employment opportunities. This study evaluates the performance, emission levels, and suitability for promotion for mass production of a novel updraft gasifier biomass cookstove. The assessment, conducted using WBT 4.2.3 protocol, focused on thermal efficiency, carbon monoxide (CO) emissions, particulate matter (PM2.5) emissions, and safety, in accordance with ISO/IWA Tier 4 standards. PM2.5 emissions were prioritised due to their significant health impacts. A Multiple Criteria Decision Analysis (MCDA) was used to assess the cookstove's potential for mass production, considering criteria such as manufacturability, scalability, fuel savings, usability, durability, maintainability, portability, cost/affordability, safety, weight, space, and cultural acceptability. The Results showed that the stove achieved Tier 2 thermal efficiency (≈25%). Indoor air quality tests revealed Tier 2 CO emissions at both low and high power, while PM2.5 emissions met Tier 3 at high power and Tier 2 at low power. The safety score was 59/100, corresponding to Tier 1. Compared to the traditional 3-stone fire, the stove demonstrated superior efficiency, indoor air quality, specific fuel consumption, and safety. In the MCDA evaluation, the stove ranked second among five models, confirming its suitability for commercial-scale production, although continuous improvement is required. This study highlights the potential of the first updraft gasifier biomass cookstove tested in Cameroon to contribute to sustainable energy solutions.
Abstract: In Cameroon, renewable energy promotion is a key strategy for improving energy security and fostering employment opportunities. This study evaluates the performance, emission levels, and suitability for promotion for mass production of a novel updraft gasifier biomass cookstove. The assessment, conducted using WBT 4.2.3 protocol, focused on thermal...
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Research Article
Mechanical Performance of SLM-Manufactured Bolts Under Varying Torque Conditions for Aerospace Applications
Mudda Nirish*
,
Koganti Rajendra Prasad,
Koganti Lavanya
Issue:
Volume 13, Issue 2, April 2025
Pages:
73-85
Received:
26 February 2025
Accepted:
14 March 2025
Published:
31 March 2025
DOI:
10.11648/j.ijmea.20251302.13
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Abstract: This research study examines the mechanical performance of bolts fabricated using Selective Laser Melting (SLM), a Laser Powder Bed Fusion (LPBF) technique widely utilized in the aerospace and automotive industries for producing lightweight, high-performance components. To improve mechanical properties through SLM, building orientation plays a crucial role, particularly in enhancing fatigue strength. This study examines the bolts mechanical properties by using SLM optimal process parameters, including laser power of 225 W, scan speed of 500 mm/s, and hatching distance of 100 µm. This study investigates the mechanical performance of M5, M6, and M8 hexagonal bolts with a focus on tensile strength, creep resistance and effects of torque tightening on fatigue life. Tensile testing demonstrated the bolts’ high strength, achieving an ultimate tensile strength (UTS) of 1189.32 MPa and a yield strength (YS) of 967.61 MPa at room temperature with a crosshead speed of 1 mm/min. Fatigue testing, conducted under pre-load and torque-applied conditions, revealed that proper torque application significantly enhanced fatigue life, extending it from 21,000–25,000 cycles in pre-load conditions to 135,000 cycles under a torque of 12 N-mm. Additionally, creep testing confirmed the material’s long-term stability, showing no deformation or failure when subjected to a sustained load of 660 MPa over a 24-hour period. These results emphasize the critical role of torque tightening in improving fatigue performance and highlight the reliability of the bolts under prolonged stress, making them suitable for high-performance applications in the automotive and aerospace industries.
Abstract: This research study examines the mechanical performance of bolts fabricated using Selective Laser Melting (SLM), a Laser Powder Bed Fusion (LPBF) technique widely utilized in the aerospace and automotive industries for producing lightweight, high-performance components. To improve mechanical properties through SLM, building orientation plays a cruc...
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