Research Papers - Department of Mechanical Engineering

Permanent URI for this collectionhttps://rda.sliit.lk/handle/123456789/604

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Author: search.filters.author.Perera, CStart date: 2022

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Now showing 1 - 3 of 3
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    Evaluating and prioritizing delay factors in naval ship maintenance using the analytic hierarchy process: a Sri Lanka navy shipyard case study
    (Taylor and Francis Ltd., 2026-02-18) Fernando, W. J; Silva, N; Perera, C
    Timely maintenance of ships and craft is critical for ensuring operational readiness, safety, and economic sustainability in the maritime sector. However, scheduled docking delays remain a persistent challenge globally, incurring significant financial losses and reducing fleet availability. This study presents a systematic, quantitative approach to identify and prioritize 22 critical factors causing delays in scheduled docking. Using the Analytic Hierarchy Process (AHP), the study evaluates the relative importance of these factors to support informed decision-making. A case study of the Sri Lanka Navy (SLN) demonstrates the application of the proposed framework, revealing that 97% of docking delays occur before vessels enter the dock, with 31.8% of these delays attributable to deficiencies in the procurement of materials and spare parts. While the findings are based on a single case study of the SLN shipyard, they offer context-specific insights into the unique challenges faced by naval maintenance operations in developing regions.
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    Evaluating and prioritizing quality culture elements in the tire manufacturing industry: A case-based DEMATEL approach
    (Taylor and Francis Ltd., 2026-01-16) Silva, N; Bandara, S; Perera, C
    In today’s competitive manufacturing environment, developing a robust quality culture that supports continuous improvement and defect prevention is critical for long-term operational excellence and customer satisfaction. This study applies the Decision-Making Trial and Evaluation Laboratory (DEMATEL) method to evaluate and prioritize the key elements shaping quality culture in a leading tire manufacturing company in Sri Lanka, offering a rare empirical application of DEMATEL in this context. Using a two-phase approach, Phase 1 involved a survey of 127 employees to identify seven critical elements, while Phase 2 analyzed expert evaluations from 16 professionals to establish causal relationships among them. The findings reveal that leadership (R + C = 14.40) and employee empowerment (R + C = 13.31) are the most influential drivers, followed by teamwork (R + C = 12.67), while focus on customer satisfaction, planning for quality, improvements and innovation, and standardized processes approach are primarily dependent elements. The built-in quality maturity framework and relative importance index were applied to assess the current implementation level of each element and identify performance gaps. The gap analysis highlights that leadership and employee empowerment are underperforming relative to expected levels, requiring immediate strategic enhancement. Managers should prioritize leadership and empowerment development to strengthen organizational quality culture and sustain competitiveness.
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    PublicationOpen Access
    Design and Fabrication of a Novel Hybrid Solar Dryer
    (SLIIT, 2022-02-11) Perera, C; Fernando, G; Liyanage, M
    A hybrid solar dryer was designed and tested for commercial dissemination of active and passive drying methods over traditional sun drying methods. The proposed dryer employs novel features such as user controllability of the drying parameters and includes sensors and controllers for active monitoring of drying parameters. The functionality of the dryer is broadened by using logic control whereby intermittent drying patterns are introduced to the system for more efficient operation. This paper documents the design calculations and fabrication process of the dryer as well as the results of drying obtained under a controlled environment. 10 experiments have been carried out to assess the limits and potential improvements to the system which yielded satisfactory conditions with a temperature fluctuation of ±1℃ and change in %RH of ±2% at any given temperature within the specified limits. The developed system has been used for drying apples which yielded dried products from an initial weight of 346 grams to a final weight of 55 grams in 5 hours in pure convection and the same initial weight was reduced to 52 grams in 3 hours when operating in solar hybrid mode. The average energy consumption of the dryer was obtained at 300 Watts at uninterrupted solar insolation operation and 224 Watts during pure convective operation, portraying the efficient operation of the system to be eligible to be powered by a solar-powered energy storage