Studi Upaya Penghematan Energi Listrik pada Gedung Asthabrata PT Mekar Armada Jaya

Audit energi merupakan kegiatan untuk mengidentifikasi jenis energi dan mengidentifikasikan besarnya energi yang digunakan pada bagian-bagian operasi suatu industri/pabrik atau bangunan serta mencoba mengidentifikasi kemungkinan penghematan energi. Audit energi yang dilakukan pada yaitu fokus pada penggunaan sistem pencahayaan dan sistem pendinginan. Gedung Asthabrata merupakan gedung di PT Mekar Armada Jaya yang berada di tengah-tengah kawasan autobody manufacturing PT Mekar Armada Jaya. Gedung yang digunakan sebagai kantorBidang Engineering. Dari data yang didapat konsumsi energi Gedung Asthabrata untuk sistem pencahayaan yaitu sebesar 50,8 kWh perhari, untuk sistem pendinginan sebesar 143,48 kWh perhari. Tingkat pencahayaan semua ruangan di gedung Asthabrata belum memenuhi standar yang ditetapkan oleh Badan Standar Nasional Indonesia. Kapasitas AC untuk semua ruangan di gedung Asthabrata belum memenuhi standar menurut perhitungan rumus yang ditetapkan. Hasil dari simulasi penghematan dapat disimpulkan bahwa dengan menggunakan lampu jenis LED dapat mengurangi jumlah energy sebesar 55% dari lampu jenis flourence. Untuk sistem pendinginan dilakukan simulasi penghematan dapat diketahui bahwa dengan menggunakan AC jenis inverter dapat mengurangi jumlah energy sekitar 56% dari AC jenis biasa. Dilihat dari simulasinya dapat ditarik kesimpulan bahwa simulasi ketiga dengan AC merek B paling signifikan dalam mengurangi jumlah penggunaan energy sebesar to73,1 kWh/hari. Kata Kunci: Audit energi, Sistem pencahayaan, Sistem pendingina

Analisis Kegagalan Baut Exhausted Lokomotif Mesin Diesel Elektrik Ditinjau dari Struktur Mikro Material dan Distribusi Tegangan oleh Momen Puntir

Lokomotif merupakan bagian dari kereta api dimana terdapat mesin untuk menggerakkan kereta api. Salah satu jenis dari kereta api di Indonesia yaitu menggunakan mesin diesel. Pada mesin diesel terdapat exhaust yang berfungsi sebagai saluran pembuangan gas emisi. Perawatan lokomotif memungkinkan terjadinya patah pada baut exhaust. Penelitian ini bertujuan untuk mengetahui penyebab kegagalan dari baut yang dipakai pada exhaust lokomotif diesel dengan meninjau perubahan struktur mikroskopik yang terjadi pada baut dengan kondisi temperature tinggi dan mengetahui distribusi tegangan yang terjadi pada baut pada saat pelepasan. Kondisi pada daerah exhaust lokomotif kereta api dapat mencapai diatas 750°C menyebabkan perubahan struktur kristal dari material pada baut. Modulus kegagalan punter lebih rawan terjadi pada material ulet. Material baut SAE grade 5 ukuran 1 inch memiliki nilai torsi maksimum material 885,8 N.m dengan nilai standardnya yaitu 664 N.m. Dengan demikian menunjukkan bahwa pada saat temperature ruang torsi yang diberikan pada saat pelepasan baut memiliki nilai yang aman, namun dengan meningkatnya temperature menurunkan nilai tegangan maksimum material baut untuk terdeformasi puntir

Finite Element Analysis of Road Roughness Effect on Stress Distribution of Heavy Duty Truck Chassis

Finite Element Method is one of the most powerful methods in numerical analysis techniques. The time consuming tasks and high costs can be reduced by using this method in the early stages of machine component design. The truck chassis is a base component of vehicles and integrates many of the truck component systems such as the axles, suspension, power train, cab and trailer. The truck chassis has been loaded by static, dynamic and also cyclic loading. Static loading comes from the weight of cabin, its contents and passengers. The movement of truck affects a dynamic loading to the chassis. The vibration of engines and the roughness of roads give a cyclic loading. The chassis used in trucks has almost the same appearance since models were developed 20 or 30 years ago, denoting that they are a result of slow and stable evolution of these frames throughout the years. The manufacturers of these chassis, in the past, and some still today, solve their structural problems by trial and error. Conducting experimental tests in the early stage of design are time consuming and expensive. In order to reduce these costs, it is important to conduct simulations using numerical software methods to find the optimum design. Determination of static, dynamic and fatigue characteristics of a truck chassis before manufacturing is important for design improvement. This paper presents the finite element analysis (FEA) of road roughness effects on stress distribution of heavy duty truck chassis

Penggunaan metode Reliability-Centered Maintenance untuk menjaga keandalan material belt conveyor

Alat transportasi berperan penting dalam mengangkut material konsentrat untuk diolah dalam pabrik smelter secara kontinyu. Peralatan tersebut dijaga agar selalu beroperasi tanpa ada kerusakan. Kerusakan alat dapat mengakibatkan terhentinya proses produksi. Oleh karena itu manajemen peralatan pabrik sangat penting, dengan melakukan maintenance secara berkala untuk menghindari kejadian yang tidak diinginkan. Permasalahan yang sering terjadi pada salah satu alat yaitu belt conveyor adalah adanya tumpahan material ketika beroperasi. Penelitian ini menerapkan metode Reliability Centered Maintenance untuk mengetahui solusi yang tepat atas permasalahan sehingga material belt conveyor memiliki kehandalan yang tinggi dan umur pakainya meningkat. Hasil penelitian menunjukkan bahwa failure mode yang terjadi pada belt conveyor merupakan kategori C dan memiliki persentase terbesar sehingga dampak kerugian ekonominya relatif kecil. Namun tetap demikian kemungkinan terjadinya outage pada plant tetap harus diperhatikan

Tresca stress study of CoCrMo-on-CoCrMo bearings based on body mass index using 2D computational model

Many investigations for developing total hip arthroplasty performance presented in previous literature show focusing on implant users' external factors. Although this is important, assessing loading based on implant user’s weight also needs to be examined as it contributes to overall performance of this prosthesis. Our study attempted to evaluate Tresca stress in CoCrMo-on-CoCrMo hip implant based on body mass index from patient. 2D computational model in this paper has been establishing to reach this objective. Loading variation is also considered with different body mass index categories from underweight, normal, overweight, obese class I, obese class II, and obese class III under normal walking condition. We found that Tresca stress rises with higher body mass index category

Minimizing Risk of Failure from Ceramic-on-Ceramic Total Hip Prosthesis by Selecting Ceramic Materials Based on Tresca Stress

The choice of ceramic-on-ceramic coupling in total hip prosthesis has advantages over couplings with other combinations of materials that use polyethylene and metal materials in terms of high hardness, scratch resistance, low wear rate, and increased lubrication performance. To reduce the risk of primary postoperative failure, the selection of ceramic materials for ceramicon-ceramic coupling is a strategic step that needs to be taken. The current study aims to analyze ceramic-on-ceramic coupling with commonly used ceramic materials, namely zirconium dioxide (ZrO2), silicon nitride (Si3N4), and aluminium oxide (Al2O3), according to Tressa failure criterion for the investigation of the stress distribution. A two-dimensional axisymmetric finite element-based computational model has been used to evaluate the Tresca stress on ceramic-on-ceramic coupling under gait cycle. The results show that the use of ZrO2-on-ZrO2 couplings can reduce Tresca stress by about 17.34% and 27.23% for Si3N4-on-Si3N4 and Al2O3-on-Al2O3 couplings, respectively

The Optimization of Production Zeolite Synthesis Y From Rice Husk Ash

Rice husk is the milling byproduct of rice and is a major waste product of the agriculture industry. Amorphous silica, commonly referred to as rice husk ash, was extracted from rice husk by acid leaching, pyrolysis, and carbon-removing processes. On the other hand, the pure silica with a high specific surface area, high melting point and high porosity can be obtained from rice husks. These properties make the ash a valuable raw material for many industries. This paper is study of synthesized of zeolite Y from rice husk ash. Zeolite Y synthesis is used for petroleum industry as expensive catalyst. Rice husk was calcined at temperature 700oC for two hours using furnace to produce pure silica . The composition of synthesized of zeolite Y from rice husk was 2.24 Na2O : Al2O3 : 8 SiO2 : 112 H2O. The gel solution was mixed at room temperature for 24 hours using autoclave. Then, the gel solution was heated with variable temperature and time crystallization. The product zeolite synthesis Y was filtered and washed with distilled water until pH lower than ten, than dried at oven. This product was analyzed with X-Ray Diffraction (XRD). From XRD analyze result indicated that from rice husk ash can produced zeolite synthesis Y which high structure and crystallization degree. The optimum condition for synthesized zeolite Y from rice husk ash was temperature 100oC for 48 hours

Stress analysis of heavy duty truck chassis using finite element method

One of the most important steps in development of a new truck chassis is the prediction of fatigue life span and durability loading of the chassis frame. The age of many truck chassis in Malaysia are of more than 20 years and there is always a question arising whether the chassis is still safe to use. Thus, fatigue study and life prediction on the chassis is necessary in order to verify the safety of this chassis during its operation. Stress analysis using Finite Element Method (FEM) can be used to locate the critical point which has the highest stress. This critical point is one of the factors that may cause the fatigue failure. The magnitude of the stress can used to predict the life span of the truck chassis. In this study, the stress analysis is accomplished by the commercial finite element packaged ABAQUS

Stress analysis of heavy duty truck chasis as a preliminary data for its fatigue life prediction using FEM

This paper presents the stress analysis of heavy duty truck chassis. The stress analysis is important in fatigue study and life prediction of components to determine the critical point which has the highest stress. The analysis was done for a truck model by utilizing a commercial finite element packaged ABAQUS. The model has a length of 12.35 m and width of 2.45 m. The material of chassis is ASTM Low Alloy Steel A 710 C (Class 3) with 552 MPa of yield strength and 620 MPa of tensile strength. The result shows that the critical point of stress occurred at the opening of chassis which is in contact with the bolt. The stress magnitude of critical point is 386.9 MPa. This critical point is an initial to probable failure since fatigue failure started from the highest stress point