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"Analisa kegagalan adalah suatu metode atau usaha untuk menyelidiki sebab-sebab kegagalan suatu komponen peralatan. Suatu komponen dikatakan gagal apabila komponen tersebut tidak dapat berfungsi seperti yang dirancang. Sucker rod pump sebagai salah satu dari metode produksi artificial lift memiliki beberapa keuntungan, beberapa diantaranya yaitu efisien dan mudah dalam pengoperasian di lapangan, masih bisa digunakan untuk mengangkat fluida pada sumur yang mengandung pasir, dapat dipakai pada sumur bengkok (directional), dapat digunakan untuk sumur yang memiliki tekanan rendah, fleksibel karena kecepatan pompa dan stroke length dapat disesuaikan, dapat digunakan pada berfungsiukuran tubing. Namun tak jarang pula sucker rod pump ini mengalami masalah yang menyebabkan berkurangnya kemampuan berproduksi pada suatu sumur minyak, bahkan menyebabkan terhentinya produksi (off). "

"Analisa kegagalan adalah suatu metode atau usaha untuk menyelidiki sebab-sebab kegagalan suatu komponen peralatan. Suatu komponen dikatakan gagal apabila komponen tersebut tidak dapat berfungsi seperti yang dirancang. Sucker Rod Pump sebagai salah satu dari metode produksi artificial lift memiliki beberapa keuntungan, beberapa diantaranya yaitu efisien dan mudah dalam pengoperasian di lapangan, masih bisa digunakan untuk megangkat fluida pada sumur yang mengandung pasir, dapat dipakai pada sumur bengkok (directonal), dapat digunakan pada sumur yang memiliki tekanan rendah, fleksibel karena kecepatan pompa dan stroke length dapat disesuaikan, dapat digunakan pada berbagai ukuran tubing. Namun tak jarang pula Sucker Rod Pump ini mengalamai masalah yang menyebabkan berkurangnya kemampuan berproduksi suatu sumur minyak, bahkan menyebabkan terhentinya produksi (off). Masalah yang terjadi kebanyakan disebabkan oleh kerusakan yang dialami oleh ball, seat, and cage yang merupakan salah satu bagian vital dalam operasi stucker rod pump. Ball, seat, dan cage yang dipergunakan martensitic stainless steel. Dalam klasifikasi AISI termasuk dalam AISI 440. Banyak alternatif penanggulangan kerusakaan ball, seat, adn cage yang dapat dilakukan, namun perlu disesuaikan dengan kondisi sumur atau lapangan dimana sumur tersebut berada. Dari beberapa alternatif itulah akan dipih cara penanggulangan yang efisien baik secara pemilihan material maupun peralatan penunjang lainnya."

"Pengujian fatigue dilakukan pada material komposit fiber glass berjenis woven roving dengan epoxy sebagai matriksnya. Material yang diuji merupakan material yang lolos uji pada serangkaian uji mekanik statis sebelumnya, yaitu WR 200 asimetris epoxy dan WR 400 asimetris-epoxy. Material ini dibuat dengan metode Vacuum Assisted Resin Infusion (VARI) pada suhu ruang. Hasil pengujian fatigue dilanjutkan dengan ekstrapolasi data dari kurva S-N dengan Matlab 7.4 yang berisi curve fitting probabilitas kegagalan untuk memperkirakan masa pakai material. Hasil curve fitting menunjukkan material mempunyai daya tahan di atas siklus 108 untuk pemakaian sekitar 20 tahun. Hasil pengamatan dengan mikroskop optik dan Scanning Electron Microscope (SEM) menunjukkan mekanisme kegagalan material akibat uji fatigue, diawali dengan retaknya matriks, putusnya ikatan permukaan matriks-fiber, diikuti putusnya fiber yang menyebabkan patahnya material.

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Fatigue test was carried out on composite materials with the type of woven roving fiberglass with an epoxy as a matrix. The specification of the fatigue tested materials was selected from previous static mechanical tests, namely WR 200 asymmetric-epoxy and WR 400 asymmetric-epoxy. These materials were produced by using Vacuum Assisted Resin Infusion (VARI) at room temperature. The fatigue test result followed by extrapolation of data from the S-N curve with Matlab 7.4 curve fitting, which contains the probability of failure to estimate the lifetime of the materials.

Curve fitting results indicate the materials have a resistance above 108 cycles for the use of about 20 years. The observation with optical microscope and Scanning Electron Microscope (SEM) shows the mechanism of failure due to fatigue test, begins from a matrix cracking, followed by a fiber-matrix interfacial debonding, then a fiber breakage that caused the final fracture."

"[ABSTRAKMaterial Bake Hardening merupakan material yang memiliki sifat mudah dideformasi sebelum diberi perlakuan panas dan sulit dideformasi setelah diberi perlakuan panas. Material ini merupakan material baru yang digunakan pada industri otomotif untuk digunakan pada kerangka mobil dan badan mobil. Material ini akan disambungkan menggunakan mesin Resistance Spot Welding. Resistance Spot Welding merupakan salah satu jenis pengelasan yang banyak digunakan di industri otomotif. Penelitian ini bertujuan untuk mengetahui pengaruh dari parameter kuat arus dari mesin resistance spot welding pada material bake hardening. Penyambungan material bake hardening ini dilakukan dengan menggunakan mesin resistance spot welding dengan pemberian kuat arus 8kA, 9kA, 10kA, 11kA dan 12kA. Pengujian yang dilakukan antara lain pengujian kekerasan, geser, pengamatan SEM, dan metalografi. Hasil penelitian menunjukkan bahwa kekuatan optimum yaitu 5,68kN dan kekerasan optimum yaitu 237,34 VHN didapat pada sampel yang diberi kuat arus sebesar 11kA. Pemberian kuat arus diatas 11kA akan menyebabkan penurunan pada kekuatan dan kekerasan. Pola penjejakan kekerasan menunjukkan bahwa daerah nugget memiliki kekerasan yang lebih tinggi dibandingkan base metal. Struktur mikro juga menunjukkan bahwa semakin ke daerah nugget, butir semakin membesar dan fasa bainite bertambah banyak.

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ABSTRACT

Bake Hardening material is a material that is easily deformed before being given a heat treatment and become a hard deformed after being heat-treated. This material is a new material used in the automotive industry for car frame and car body. This material will be welded using Resistance Spot Welding machine. Resistance Spot Welding is one type of welding that is widely used in the automotive industry. This study aims to determine the effect of the current welding parameters of resistance spot welding to bake hardening material. The joining of bake hardening material is performed using resistance spot welding machine with current 8kA, 9kA, 10kA, 11kA and 12kA. Tests performed include hardness testing, shear, SEM and metallography. The results showed that the optimum tensile strength is 5,68kN and optimum Vickers hardness is 237.34 VHN samples were obtained at a current of 11kA. Giving current 11kA above will cause a decrease in tensile strength and Vickers hardness. Hardness distribution of Vickers hardness shows that nugget area has a higher hardness than the base metal. Microstructure also shows that the area to the nugget, grain growing and increasing bainite phase.;Bake Hardening material is a material that is easily deformed before being given a heat treatment and become a hard deformed after being heat-treated. This material is a new material used in the automotive industry for car frame and car body. This material will be welded using Resistance Spot Welding machine. Resistance Spot Welding is one type of welding that is widely used in the automotive industry. This study aims to determine the effect of the current welding parameters of resistance spot welding to bake hardening material. The joining of bake hardening material is performed using resistance spot welding machine with current 8kA, 9kA, 10kA, 11kA and 12kA. Tests performed include hardness testing, shear, SEM and metallography. The results showed that the optimum tensile strength is 5,68kN and optimum Vickers hardness is 237.34 VHN samples were obtained at a current of 11kA. Giving current 11kA above will cause a decrease in tensile strength and Vickers hardness. Hardness distribution of Vickers hardness shows that nugget area has a higher hardness than the base metal. Microstructure also shows that the area to the nugget, grain growing and increasing bainite phase., Bake Hardening material is a material that is easily deformed before being given a heat treatment and become a hard deformed after being heat-treated. This material is a new material used in the automotive industry for car frame and car body. This material will be welded using Resistance Spot Welding machine. Resistance Spot Welding is one type of welding that is widely used in the automotive industry. This study aims to determine the effect of the current welding parameters of resistance spot welding to bake hardening material. The joining of bake hardening material is performed using resistance spot welding machine with current 8kA, 9kA, 10kA, 11kA and 12kA. Tests performed include hardness testing, shear, SEM and metallography. The results showed that the optimum tensile strength is 5,68kN and optimum Vickers hardness is 237.34 VHN samples were obtained at a current of 11kA. Giving current 11kA above will cause a decrease in tensile strength and Vickers hardness. Hardness distribution of Vickers hardness shows that nugget area has a higher hardness than the base metal. Microstructure also shows that the area to the nugget, grain growing and increasing bainite phase.]"

"Penggunaan pompa air listrik satu fasa sebagai turbin-generator pembangkit listrik pikohidro menguntungkan untuk digunakan karena murah, sederhana, kokoh, mudah dipasang dan mudah dibeli di mana-mana. Sesuai standard yang berlaku pembangkit listrik harus memiliki luaran tegangan dan frekuensi dengan rentang kesalahan tunak yang aman dalam mensuplai peralatan. Untuk memenuhi kriteria ini terdapat beberapa masalah, antara lain; pompa air yang digunakan sebagai turbin tidak dilengkapi dengan pengendali putaran, pabrikan pompa tidak menyediakan data model dinamik dari pompa air untuk mode operasi turbin, serta efek cross-coupling antara loop pengendali tegangan dan loop pengendali frekuensi.Dalam penelitian ini permasalahan pengendalian frekuensi diselesaikan dengan menerapkan metode Electric Balanced Load, masalah penentuan model dinamik diselesaikan dengan metode estimasi data-driven, dan masalah efek cross-coupling diselesaikan dengan menambahkan blok decoupling pada model sistem pengendali. Ketiga solusi ini diimplementasikan dalam bentuk desain pengendali frekuensi dan tegangan menggunakan pengendali PID ganda. Pemilihan nilai parameter PID yang tepat, menghasilkan respons tegangan dan frekuensi luaran pembangkit yang dapat memenuhi persyaratan yang berlaku.Dari beberapa skenario simulasi menggunakan Matlab Simulink menghasilkan nilai kesalahan tunak tertinggi pada luaran frekuensi dan tegangan masing-masing 0,0008 pu dan 0,0015 pu serta settling time masing-masing 15 detik dan 11 detik. Dengan menambahkan modul pengendali tegangan dan frequensi seperti yang diterapkan pada penelitian ini dapat disimpulkan bahwa pompa air listrik kapasitas 250-watt secara teknis layak untuk dikembangkan sebagai turbin-generator pembangkit listrik pikohidro dengan nilai toleransi tegangan dan frekuensi luaran generator yang aman untuk konsumsi peralatan listrik rumah tangga.

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The use of a single-phase electric water pump as a picohydro turbine-generator is advantageous tobe use because it is cheap, simple, sturdy, easy to install and easy to purchase. The Electric Power Generation which supplying the electric power to the consumer must have the quality of Voltage and Frequency comply to a specific standard code. The standard code mentioned that the power generation must have an output voltage within tolerance +/-10% and the frequency tolerance within -5% and +10%. To meet these criteria, this system has several problems such as; the water pump which used as the turbine do not equipped with mechanical governor, the pump manufacturer does not provide dynamic model data for the turbine operating mode, and the effect of cross-coupling between the voltage control loop and the frequency control loop.In this research, frequency control problems are solved by applying the Electric Balanced Load method, the problem of determining the dynamic model is solved by the Data-Driven Estimation method, and the problem of Cross-coupling effects solved by adding the Decoupling Blocks Compensator in the Dynamic Model Block of the Controller. These three solutions are implemented in the form of a Frequency and Voltage Controller design by using a dual PID controller. The selection of the right PID parameter values resulting a voltage and frequency output response of the generator which meet the requirements of the applicable standard code.From the simulation scenarios by using Matlab Simulink resulting a highest Steady State Error value of generator voltage and frequency 0,0008 pu and 0,0015 pu respectively as well as settling time 15 second and 11 second. Based on the results of the simulation study it can be concluded by added such frequency and voltage controller the single phase 250-watt electric water pump used in this study technically feasible to be developed as a turbinegenerator in a picohydro power plant."

"The flat plate ship is a ship that is being developed and has entered the mass production stage of the Ministry of Research and Technology Republic of Indonesia. This is related to the function of flat plate vessels that are suitable with the conditions and needs of the Indonesian state, namely the massive production of marine fleets. Flat plate ships provide advantages including production cost efficiency which is far more economical than ships in general because it does not go through the bending process, so does the production time which can be shortened. But the flat plate ship still needs improvement, one of them is the ship propulsion.This study will combine a flat plate ship tunnel with a ducted propeller as an effort to increase thrust and hydrodynamic efficiency, with the ultimate goal of reducing fuel demand from flat plate vessels. The title of the research that was raised was the Analysis of the Combination of the Use of Tunnel and Ducted Propeller Against Increased Thrust on Flat Plate Ships: Trawler Fishing.The research method used is bollard pull / trawl pull using reference bollard pull guidelines - ITTC. Using a 70cm model ship with three configurations to be a comparison of the resulting value. The configuration used is conventional fishing trawler type flat plate without tunnel, and flat plate ship with Tunnel with all configurations using open and ducted propeller.This study succeeded in producing the desired destination with a combination of Tunnel and Ducted able to increase hydrodynamic efficiency and thrust values compared to other configurations. So that this research is expected to be one of the references to propulsion solutions and designs on flat plate vessels."