THE INFLUENCE OF PROBLEM BASED LEARNING MODEL AND LEARNING MOTIVATION ON LEARNING OUTCOMES OF LIGHT VEHICLE ENGINE MAINTENANCE LESSONS

Abstract:. The purpose of this study is to test 1) The existence of learning outcomes of Light Vehicle Engine Maintenance (PMKR) between students who get the Problem Based Learning (PBL) learning model and learning motivation on sent learning outcomes with conventional learning models, 2) There is an interaction between the PBL learning model and learning motivation on learning outcomes in PMKR lessons. 3) There are differences in the PMKR learning outcomes of students who have high learning motivation who receive the PBL learning model treatment. 4) There are differences in learning outcomes of light vehicle engine maintenance students who have low learning motivation who get the PBL learning model. This study used an experimental method with a 2 x 2 factorial design. The population was 80 students, the sample to be used was 66 students taken using smple random sampling technique. Then from the 66 students into 2 groups where Group 1 gathered 33 students into the Experiment Class which was taught with the PBL learning model and Group 2 returned 33 students from the Control class who were taught by the conventional model. The results showed that there were differences in learning outcomes between students who received treatment Problem Based Learning learning model and students who received conventional learning model treatment. There is an interaction between the learning model and learning motivation. Students who have learning motivation are more suited to the PBL model, while students who have low learning motivation are more suited to using the conventional model.

Comparison of Visual and Visual–Tactile Inspection of Aircraft Engine Blades

Background—In aircraft engine maintenance, the majority of parts, including engine blades, are inspected visually for any damage to ensure a safe operation. While this process is called visual inspection, there are other human senses encompassed in this process such as tactile perception. Thus, there is a need to better understand the effect of the tactile component on visual inspection performance and whether this effect is consistent for different defect types and expertise groups. Method—This study comprised three experiments, each designed to test different levels of visual and tactile abilities. In each experiment, six industry practitioners of three expertise groups inspected the same sample of N = 26 blades. A two-week interval was allowed between the experiments. Inspection performance was measured in terms of inspection accuracy, inspection time, and defect classification accuracy. Results—The results showed that unrestrained vision and the addition of tactile perception led to higher inspection accuracies of 76.9% and 84.0%, respectively, compared to screen-based inspection with 70.5% accuracy. An improvement was also noted in classification accuracy, as 39.1%, 67.5%, and 79.4% of defects were correctly classified in screen-based, full vision and visual–tactile inspection, respectively. The shortest inspection time was measured for screen-based inspection (18.134 s) followed by visual–tactile (22.140 s) and full vision (25.064 s). Dents benefited the most from the tactile sense, while the false positive rate remained unchanged across all experiments. Nicks and dents were the most difficult to detect and classify and were often confused by operators. Conclusions—Visual inspection in combination with tactile perception led to better performance in inspecting engine blades than visual inspection alone. This has implications for industrial training programmes for fault detection.

Numerical and Experimental Assessment of the Effect of Residual Stresses on the Fatigue Strength of an Aircraft Blade

The work presents the results of numerical fatigue analysis of a turbine engine compressor blade, taking into account the values of initial stresses resulting from surface treatment-shot-peening. The values of the residual stresses were estimated experimentally using X-ray diffraction. The paper specifies the values of the residual stresses on both sides of the blade and their reduction due to cutting through the blade-relaxation. The obtained values of the residual stresses were used as initial stresses in the numerical fatigue analysis of the damaged compressor blade, which was subjected to resonant vibrations of known amplitude. Numerical fatigue ε-N life analysis was based on several fatigue material models: Manson’s, Mitchell’s, Baumel-Seeger’s, Muralidharan-Manson’s, Ong’s, Roessle-Fatemi’s, and Median’s, and also on the three models of cyclic hardening: Manson’s, Xianxin’s, and Fatemi’s. Because of this approach, it was possible to determine the relationship between the selection of the fatigue material ε-N model and the cyclic hardening model on the results of the numerical fatigue analysis. Additionally, the calculated results were compared with the results of experimental research, which allowed for a substantive evaluation of the obtained results. These results are of great scientific and practical importance. The problem of determining the fatigue life of blades with defects operating under resonance vibrations is one of the original tasks in the field of fracture mechanics and experimental mechanics. The results obtained are of great importance in the aviation industry and can be used during engine maintenance and inspections to assess the suitability of blades with defects in terms of the needs of further work. This aspect of engineering maintenance is of great importance from the aircraft safety point of view.

Increasing Wells Lifetime by Using PAR VALVE to Overcome Sand Settling Problems at Pertamina EP Asset 1 Field Jambi

In the Jambi oil field, sand production can create unattainable production targets and short-lived well lifetime. One function of the Jambi Engineering and Planning Field is to look for solutions to these problems, such as the installation of progressive cavity pumps (PCP) into wells. Although successful, a problem that often arises in PCP wells is sand settling when the PCP is off, for example during electric trips, engine maintenance and repair of flowlines. This settling can lead to a stuck PCP. A recent solution has been to install a Pressure Actuated Relief (PAR) valve, where the tool directs sand deposits out of the tubing to the annulus so that it does not enter the pump. Installation of this tool has increased the average lifetime of sandy wells from 2 months to 6 months, and has increased oil production in these wells by up to 47%.This paper will discuss the successful installation of a PAR Valve into well KTT-08 in the Jambi Field.

Numerical and Experimental Assessment of the Effect of Residual Stresses on the Fatigue Strength of an Aircraft Blade

The work presents the results of numerical fatigue analysis of a turbine engine compressor blade, taking into account the values of initial stresses resulting from surface treatment - shot-peening. The values of the residual stresses were estimated experimentally using X-ray diffraction. The paper specifies the values of the residual stresses on both sides of the blade and their reduction due to the cutting through the blade - relaxation. The obtained values of the residual stresses were used as initial stresses in the numerical fatigue analysis of the damaged compressor blade, which is subjected to resonant vibrations of known amplitude. Numerical fatigue ε-N life analysis was based on the several fatigue material models: Manson’s, Mitchell’s, Baumel-Seeger’s, Muralidharan-Manson’s, Ong’s, Roessle-Fatemi’s and Median’s, and also on the three models of cyclic hardening: Manson’s, Xianxin’s, and Fatemi’s. Because of this approach, it was possible to determine the relationship between the selection of the fatigue material ε-N model and the cyclic hardening model on the results of the numerical fatigue analysis. Additionally, the calculated results were compared with the results of experimental research, which allowed for a substantive evaluation of the obtained results. These results are of great scientific and practical importance. The problem of determining the fatigue life of blades with defects operating under resonance vibrations is one of the original tasks in the field of fracture mechanics and experimental mechanics. The results obtained are of great importance in the aviation industry and can be used during engine maintenance and inspections to assess the suitability of blades with defects in terms of the needs of further work. This aspect of engineering maintenance is of great importance from the aircraft safety point of view.

Analisis Pemeliharaan Mesin Conveyor Menggunakan Metode Preventive dan Breakdown Maintenance untuk Meminimumkan Biaya Pemeliharaan Mesin pada PT X

This research aims to know how the implementation of maintenance conducted by PT X and how maintenance by PT X used the preventive and breakdown maintenance methods to minimize engine maintenance cost. The research method used in this study is care study whereas this type of research is quantitative descriptive research. Technique of collecting data in this research by obsererving, interviewing and collecting documents related to research. Data analysis used by using preventive and breakdown maintenance methods. The result of this research is PT X performs maintenance of the engine by using preventive maintenance such as routine maintenance, semi-overhaul forecast maintenance and annual maintenance and breakdown maintenance are usually performed when the machine is fully damaged or dead. PT X should implement preventive maintenance because it is more efficient at 13,2% than the company’s maintenance. Abstrak. Penelitian ini bertujuan untuk mengetahui bagaimana pelaksanaan pemeliharaan mesin yang dilakukan PT X dan bagaimana pemeliharaan mesin yang yang dilakukan PT X dengan menggunakan metode preventive dan breakdown maintenance untuk meminimumkan biaya pemeliharaan mesin. Metode penelitian yang dilakukan dalam penelitian ini studi kasus sedangkan jenis penelitian ini adalah penelitian deskriptif kuantitatif. Teknik pengumpulan data dalam penelitian ini dengan melakukan observasi, wawancara dan pengumpulan dokumen-dokumen yang berkaitan dengan penelitian. Analisis data yang digunakan dengan menggunakan metode preventive dan breakdown maintenance. Hasil dari penelitian ini adalah PT X hendaknya melakukan pemeliharaan mesin dengan menggunakan preventive maintenance seperti perawatan rutin, perawatan semi overhaul dan perawatan tahunan dan breakdown maintenance biasa dilakukan saat mesin mengalami kerusakan atau mati total. PT X hendaknya melaksanakan preventive maintenance karena lebih efisien sebesar 13,2% dibandingkan pemeliharaan yang dilakukan perusahaan.

Evolutionary Algorithm for Enhanced Gas Path Analysis in Turbofan Engines

Adaptive modelling (AM) based Gas Path Analysis (GPA) is a powerful diagnostic and prognostic technique for turbofan engine maintenance. This involves the assessment of turbofan component condition using thermodynamic models that can iteratively adapt to measurements values in the gas path by changing component condition parameters. The problem with this approach is that newer turbofan engines such as the General Electric GEnx-1B have fewer gas path sensors installed causing the AM equation systems to become underdetermined. To overcome this problem, a novel approach has been developed that combines the AM model with an Evolutionary Algorithm (EA) optimization scheme and applies it to multiple operating points. Additionally, these newer turbofan engines provide performance data continuously during flight. Information on variable geometry and bleed valve position, active clearance control state and power off-take is included and can be accounted for to further enhance AM model accuracy. A procedure is proposed where the selection of operating points is based on steady-state stability requirements, cycle model operating point uncertainty and parameter outlier filtering. The Gas turbine Simulation Program (GSP) is used as the non-linear GPA modelling environment. A Multiple Operating Point Analysis (MOPA) is chosen to overcome the problem of underdetermination by utilizing multiple data sets at different operating points. The EA finds the best fit of health parameter deviations by minimizing the multi-point objective function using the GSP AM model. A sub-form of the EA class named Differential Evolution (DE) has been chosen as the optimizer. Like all EAs, DE is a parallel direct search method in which a population of parameter vectors evolves following genetic operations towards an optimum output candidate. The resulting hybrid GPA tool has been verified by solving for different simulated deterioration cases of a GSP model. The tool can identify the direction and magnitude of condition deviation of 10 health parameters using 6 gas path sensors. It has subsequently been validated using historical in-flight data of the GEnx-1B engine. It has demonstrated successful tracking of engine component condition for all 10 health parameters and identification of events such as turbine blade failure and water washes. The authors conclude that the tool has proven significant potential to enhance turbofan engine condition monitoring accuracy for minimizing maintenance costs and increasing safety and reliability.

Analisis Sistem Pengelolaan Limbah B3 Di Industri Tekstil Kabupaten Bandung

ABSTRAKPenelitian ini bertujuan untuk mengetahui pengelolaan LB3 yang telah dilakukan di indsutri tekstil. Metode penelitian menggunakan metode perbandingan antara kondisi di lapangan dengan peraturan yang berlaku. Berdasarkan hasil evaluasi mengenai pengelolaan LB3 yang dilakukan oleh PT X dapat disimpulkan beberapa hal yaitu sumber LB3 berasal dari proses produksi, lumpur IPAL, boiler, labolatorium, pemeliharaan mesin, dan klinik. Jenis LB3 yang dihasilkan berasal dari sumber spesifik umum yaitu lumpur IPAL dan limbah medis, sumber spesifik khusus yaitu hanya fly ash dan sumber tidak spesifik yang meliputi lampu TL, drum bekas LB3, oli bekas dan reagen. Karakteristik LB3 terdiri dari beracun, mudah menyala, korosif dan infeksius. PT X telah melakukan pengelolaan LB3 yang meliputi aspek pengemasan dan pewadahan, pengumpulan, penyimpanan, pengangkutan dokumen pengelolaan LB3, dan pelabelan LB3. Untuk kegiatan pengangkutan PT X bekerja sama dengan pihak ketiga diantaranya adalah PT Hijau Lestari, PT PPLI, PT Khalda, dan WGI. Berdasarkan hasil analisis pengelolaan LB3 di perusahaan ini termasuk kategori baik. Upaya pengelolaan LB3 yang harus ditingkatkan yaitu pada proses pelekatan simbol dan label, pengemasan, dan penyimpanan LB3.Kata Kunci: Kabupaten Bandung, Industri Tekstil, Limbah B3,ABSTRACTThis study aims to determine the management of LB3 that has been carried out in the textile industry. The research method uses a comparison between conditions in the field and applicable regulations Based on the evaluation results on the management of hazardous materials carried out by PT X, it can be concluded several things, namely the source of hazardous materials originating from the production process, sludge from the wastewater treatment plant, boilers, laboratory, engine maintenance, and clinics. The types of hazardous materials produced come from general specific sources such are sludge from the wastewater treatment plant and medical waste, specific sources which are fly ash and non-specific sources which include lamps, drums used in hazardous materials, used oil and reagents. The characteristics of hazardous materials consist of toxic, flammable, corrosive, and infectious. PT X has managed the management of hazardous materials which includes aspects of packaging, storage, collection, storage, transportation of documents on the management of hazardous materials, and labeling of hazardous materials. For transportation activities, PT X cooperates with third parties including PT Hijau Lestari, PT PPLI, PT Khalda, and WGI. Based on the analysis the achievement of the management of dangerous substances in this company including the good category. Efforts to manage toxic and hazardous materials must be improved in the process of sticking symbols and labels, packaging, and storing toxic and hazardous materials.Keywords: Bandung Regency, Testile iIndustry, hazardous waste materials