Journal of Applied Mechanical Engineering Technology and Innovation

ANALYSIS OF DAMAGE TO RDT POWERROC T50 USING FOULT TREE ANALYSIS (FTA) METHOD

2025-08-01T15:56:15+01:00

RDT (Rock Drill Tools) Powerroc T50 is a heavy equipment widely used in the mining industry for drilling operations. Damage to this tool reduces productivity and increases maintenance costs, making a systematic analysis essential to pinpoint root causes and devise preventive measures. This study employs the Fault Tree Analysis (FTA) method to evaluate damage in the RDT Powerroc T50. The FTA facilitates hierarchical mapping of cause‐effect relationships leading to system failure. Data were gathered through direct observation, technician interviews, and review of maintenance reports and damage records. The analysis reveals 14 distinct causes for damage in the rod drill section and 7 causes in the shank adapter. Common forms of damage—fractures, wear, and cracks—are largely attributed to factors such as tool fatigue and inadequate monitoring of the machine’s life limit during maintenance. Insights from the FTA-based approach provide a systematic framework for identifying damage origins and implementing targeted mitigation strategies, thereby enhancing tool performance, reducing downtime, and lowering long-term maintenance expenses.

THE EFFECT OF THE NUMBER OF FIBER SHEETS AND NAOH CONCENTRATION ON THE IMPACT STRENGTH OF ALKALI-TREATED ARTHOCARPUS ELASTICUS PEELED FIBER COMPOSITESTITLE

2025-08-01T15:57:24+01:00

The focus of this study is the effect of NaOH alkali treatment and the number of fiber sheets on the impact strength of Artocarpus elasticus (lantung bark) fiber as a sustainable reinforcing material in natural fiber composites. However, lignin and hemicellulose can prevent the fibers from adhering to the resin. NaOH treatment improves fiber quality by removing these barriers, enhancing their mechanical properties. This study examines how differences in the number of fiber sheets and NaOH concentration affect the impact strength of the composite. The objective of this research is to determine how the number of fiber sheets, NaOH concentration, and combinations of these factors affect the impact strength of Artocarpus elasticus fiber composites subjected to impact testing. The study found that NaOH treatment significantly enhances the impact strength of lantung wood composites, with results continuing to improve. However, for the number of wood fiber sheets, the impact strength was highest after treatment with 4 wood fiber sheets. The optimal combination yielding the highest impact test results was the combination of 9% NaOH alkalization treatment with 4 fiber sheets, resulting in an impact value of 0.08 J/mm².

THE INFLUENCE OF TEMPERATURE AND SCREW ROTATION SPEED ON DIAMETER IRREGULARITY IN PLASTIC EXTRUSION USING RECYCLED PLA

2025-08-01T15:57:48+01:00

This research investigates the effect of extrusion temperature and screw rotation speed on the diameter irregularity of filaments produced from recycled polylactic acid (PLA) using a single screw plastic extruder. The study addresses the growing demand for sustainable 3D printing materials by reprocessing failed or unused PLA prints into usable filament. Experimental variables included three temperature settings (150°C, 160°C, and 170°C) and three screw rotation speeds (20 rpm, 30 rpm, and 40 rpm), producing a total of 360 diameter measurements. The results show that both temperature and screw rotation speed significantly influence diameter consistency, with screw speed having a more dominant effect. The optimal condition for achieving the target filament diameter of 1.75 mm was found at 170°C and 40 rpm, yielding a predicted diameter of 1.7378 mm with a desirability score of 0.97888. These findings confirm the potential of recycled PLA as a viable material for consistent filament production when proper extrusion parameters are applied. The test was done by using minitab software to aid the research analysis.

FAILURE ANALYSIS OF PIPES IN A CONSTRUCTION

2025-08-01T15:57:00+01:00

The high working pressure, temperature, and corrosivity of the fluid flowing in the pipe cause problems in pipe failure in operation. The purpose of the analysis is to obtain information related to working conditions at pressure, temperature, and fluid corrosivity, causes of failure, initial cracking of materials, and types of materials used in a construction. The analysis method includes tracing the results of previous pipe research, studying mechanical properties, composition, hardness, stress concentration, fluid corrosivity, heat treatment, comparison between results, discussion and conclusions. Application of pipe analysis in a construction of production facilities, and factories. The conclusions obtained include: rupture of coal boiler pipes at 1100°C, tensile strength of 48.2 MPa with fluid at 730°C; dezincification and deposits with sulfur content of ~0.60 wt%, and Cl ~9.45 wt% which are corrosive; exposure to hydrogen sulfide concentrations up to 1000 ppm, the presence of localized pitting corrosion due to chloride attack up to 88 °C; erosion rate of 26.77 mm/year and corrosion rate of 1.107 mm/year causing thinning of the elbow wall of 20# steel pipe, diameter 600 mm, thickness 10 mm; working pressure of diesel engine fuel pipe at 637.5 MPa or 63.8 Bar; and so on.

FAILURE ANALYSIS OF MECHANICAL SHAFT

2025-08-01T15:56:39+01:00

Cases of component failure from previous researchers encourage the analysis of the causes of shaft failure according to the operational conditions of production machining as an urgent matter to find the problem. The purpose of the analysis is to obtain the causes of shaft failure in production facility applications. The analysis method includes tracing the results of previous shaft research, studying the methods of testing mechanical properties, composition, hardness, simulation, stress concentration, torsional stress, bending stress, defects, cracks, scratches, inclusions, voids, corrosion, wear, heat treatment, comparison between the results, discussion and conclusions. Implementation of shaft analysis in machining, production facility construction, and research/test equipment. The conclusions obtained include: the crankshaft of the wheel loader diesel engine after operating for 4800 hours, broke at the fifth crankshaft with diameter 82 mm, the actual tensile strength of the shaft 832.3 MPa is still < DIN 1.7225 standard (42CrMo4) worth 900-1100 MPa; diameter 55.5 mm condensate pump shaft of SS 416 was broken, due to torsional fatigue from the sharp edge of the outer surface of the shaft where MnS inclusions were as a design error and MnS inclusions near the shaft surface as a metallurgical error; and so on.

OPTIMIZATION OF INJECTION MOLDING PARAMETERS IN MOLD SM20 USING THE TAGUCHI-GREY RELATIONAL ANALYSIS (GRA) METHOD FOR REDUCING SHORT-SHOT DEFECTS AND CYCLE TIME

2025-08-01T15:58:15+01:00

Injection molding has become a favorite technique of manufacturing high quality of specific plastic components. Nevertheless, typical flaws like short-shot flaws and long cycle times may jeopardize the quality of a product and decrease the productivity. This project is aimed at the optimization of three major process parameters; that is, the nozzle temperature, injection pressure, and injection time, which will be the three set at four levels to achieve an improvement in the performance of Mold SM20. The Taguchi experimental design used is an L16 orthogonal array and this makes the experimental design to be successfully reducing the number of trial required. As part of dealing with the two-fold goals of QED reduction and cycle time, Grey Relational Analysis (GRA) would be used in multi-response optimization. Gra means normalization, calculating of grey relational coefficients and the calculation of grey relational grades (GRG). The outcomes show that injection pressure can play an important role in combined response, whereas nozzle temperature and injection time present a less important role. The best combination of parameters (temperature of the nozzle 225o C, injection pressure 55 bar and injection time 2.0 sec) gave the best value of GRG, 0.841278 which indicates better performance of the process, both quality-wise as well as efficiency-wise.