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"ABSTRAKLatar belakang: transpalatal arch masih banyak digunakan pada perawatanortodonti dengan pencabutan premolar sebagai reinforced, untuk mencegahkehilangan penjangkaran. Dampak tekanan ortodonti pada jaringan periodontaldengan dan tanpa TPA dapat diketahui dengan mengetahui besar distribusi stresspada jaringan periodontal. Besar distribusi stress pada jaringan periodontal gigimolar satu dan dua secara in vivo tidak mungkin dilakukan. Maka dilakukanmelalui simulasi tiga dimensi 3D dengan Finite Element Analysis FEA .Tujuan: untuk melihat perbedaan distribusi stress minPS, maxPS dan vonMS pada gigi molar satu atas dengan TPA, TPA dan melibatkan gigi molar dua dantanpa TPA jika diberikan gaya distalisasi kaninus dengan daya sebesar 150g.Metode: Penelitian ini merupakan suatu penelitian eksperimental laboratorikdengan membuat model tengkorak secara tiga dimensi yang terdiri dari model gigimolar pertama atas dan tulang alveolar pendukungnya pada model maksila 3Ddengan TPA, dengan TPA dan melibatkan gigi molar dua dan tanpa TPA,kemudian dilakukan simulasi distalisasi kaninus dengan gaya 150g dengan FEA.Hasil: Ada perbedaan besar distribusi stress yang bermakna pada model 1 TPA ,model 2 TPA M2 dan model 3 tanpa TPA pada gigi molar satu atas dan tulangaveloar sekitar gigi molar satu atas p 0,000 ; p< 0,05 Kesimpulan: Nilai distribusi stress minPS, maxPS dan vonMS tertinggi padamodel tanpa TPA, kemudian nilainya menurun pada model TPA dan model TPAyang menyertakan gigi molar dua, baik pada gigi maupun tulang alveolar.

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Background:

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ABSTRACTThe transpalatal arch is used as a reinforced anchorage onextraction case to prevent anchorage loss. It is impossible to measure humanperiodontal stress distribution, so an alternative approach with three dimensionsimulation using Finite Element Analysis FEA .Aim: This study aimed to compare stress distribution on upper first molar dan itsalveolar bone with TPA, with TPA and upper second molar and without TPAwhen 150g force was applied during canine movement.Methods: This experimental laboratory was done with the contruction of the 3Dmodel that consist of 3D model of maksila with TPA, with TPA and upper secondmolar and without TPA. Canine distalization simulation was done with 150 gramdistalization force.Result: The result showed that stress distribution on 1st model 1 TPA , 2ndmodel 2 TPA M2 and 3rd model 3 without TPA was significantly higher onthe upper first molar and its alveolar bone.Conclusion: The highest stress distribution minPS, maxPS dan vonMS is on themodel without TPA and the number decrease on a model with TPA and modelTPA with the upper second molar."

"Di Indonesia, pengembangan produksi braket ortodonti dalam negeri sedang dikerjakan dan dibutuhkan studi lebih lanjut untuk mengetahui desain rumus bangun geometri dasar braket yang memiliki retensi terbaik. Braket ortodonti metal dapat melekat pada gigi mengandalkan retensi mekanis pada dasar braket. Analisis finite element suatu analisis dengan menggunakan model tiga dimensi untuk mempelajari dan menilai distribusi stress yang terjadi akibat aplikasi gaya geser dengan besaran dan arah tertentu. Letak konsentrasi stress yang besar diprediksi berisiko terjadi deformitas atau kegagalan. Penelitian ini menggunakan tiga jenis braket ortodonti metal insisif pertama rahang atas dengan tipe dasar braket non mesh yang ada di pasaran. Pembentukan model tiga dimensi berupa gigi insisif pertama rahang atas dengan blok tulang, tiga tipe braket, dan adhesif ortodonti. Proses simulasi dengan aplikasi gaya geser mesio-distal dan serviko-insisal sebesar 1 N. Hasil analisis finite element menunjukkan adanya perbedaan distribusi stress dari gaya geser mesio-distal dan serviko-insisal pada tiga jenis rumus bangun dasar braket di permukaan dasar braket, lapisan adhesif ortodonti, permukaan email, dan jaringan periodontal.

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In Indonesia, the development of domestic production of orthodontic brackets is underway and further studies are needed to find out the design of the basic bracket geometry formula that has the best retention. Metal orthodontic bracket can adhere to teeth surface by relying on mechanical retention in the base of the brackets. Finite element analysis is an analysis using three dimensional model to asses the stress distribution that occurs due to application of shear forces with certain magnitude and direction. The stress concentration and the distribution can be predicted and assumed to be the potential risk of deformity or failure. This study used three types of metal orthodontic brackets which available on the market. Three maxillary first incisors brackets with different bases, maxillary right incisor with periodontal tissue ,bone block, and orthodontic adhesive were construct using a software as a three dimensional model. The model were simulated with the application of shear stress mesio-distal and cervical- incisal one Newton each. Finite element analysis showed there are difference in stress distribution of mesio-distal and cervical-incisal shear stress on three types of different geometry of bracket base on the bracket base surface, orthodontic adhesive layer, enamel surface, and periodontal tissue."

"ABSTRAKProstetik merupakan salah satu inovasi di bidang kesehatan yang berfungsi untuk membantu maupun menggantikan salah satu fungsi organ. Prostetik yang ada di Indonesia saat ini masih didominasi oleh produk-produk luar negeri. Hal ini akan membuat harga prostetik menjadi tidak terjangkau oleh pasien. Seiring perkembangan zaman, metode produksi masal yang menggunakan CNC machining atau casting sudah mulai berubah ke batch yang lebih sedikit dengan menggunakan additive manufacturing seperti 3D printing. Penggunaan teknologi 3D Printing memiliki beberapa keunggulan dibandingkan dengan teknologi untuk produksi masal, di antaranya ramah proses kustomisasi, menghemat biaya bahan baku, waktu produksi lebih singkat untuk batch dengan jumlah kecil, dan lebih ramah lingkungan karena menghasilkan sedikit bahan sisa produksi. Penelitian ini dilakukan untuk dapat meningkatkan performa dari prostetik melalui sebuah desain prostetik lokal. Penentuan performa prostetik dilakukan dengan simulasi Finite Element Analysis dengan membandingkan tegangan von mises. Hasil simulasi menggambarkan bahwa desain modifikasi prostetik mampu meningkatkan performanya. Selain itu, dalam penelitian ini juga akan membahas permodelan biaya produksi prostetik antara tiga metode produksi, yaitu CNC Milling, 3D Printer FDM kelas penghobi, dan 3D Printer FDM kelas industri. Dari permodelan tersebut, terdapat dua parameter yang dibandingkan yaitu perbandingan waktu periode profit dalam nilai investasi yang sama dan perbandingan nilai investasi dengan harga jual prostetik yang sama. Hasil permodelan biaya menggambarkan bahwa teknologi 3D Printing mampu menginterupsi teknologi produksi masal CNC machining.

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ABSTRACTProsthetics is one of the innovations in health that serves to help or replace one of the organs' functions. Prosthetics in Indonesia is currently still dominated by foreign products. That will make prosthetic prices unaffordable for patients. Over the times, mass production methods that use CNC machining or casting have begun to change to fewer batches using additive manufacturing, such as 3D printing. 3D printing technology has several advantages compared to mass production technology, including friendly customization processes, saving raw material costs, shorter production time for batches in small quantities, and more environmentally friendly because it produces less material remaining production. This research conducted to improve the performance of prosthetics through a local prosthetic design. The determination of prosthetic performance is done by Finite Element Analysis simulation by comparing von mises stress. Simulation results illustrate that prosthetic modification design can improve performance. Besides, this research will also discuss the modeling of prosthetic production costs between three production methods, namely CNC Milling, hobbyist class FDM 3D Printer, and industrial class 3D Printer. From the modeling, two parameters are being compared namely the comparison of the period of profit in the same investment value and the comparison of investment values with the same prosthetic selling price. The cost modeling results illustrate that 3D Printing technology can interrupt CNC machining mass production technology."

"ABSTRAKFinite Element Method is one of the most power ful 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 elementanalysis (FEA) of road roughness effects on stress distribution of heavy duty truck chassis."

"Sendi pinggul adalah sendi yang menghubungkan tulang paha (femur) dengan tulang pinggul (pelvis). Persendian ini rentan mengalami kerusakan akibat infeksi, kecelakaan, robeknya kartilago, osteoarthritis, keausan, dan degenerasi tulang. Untuk mengatasi masalah tersebut dapat dilakukan operasi penggantian sendi atau Total Hip Arthroplasty (THA), yakni implan untuk menggantikan sendi pinggul yang rusak menjadi sendi buatan. Hal ini dilakukan untuk mengembalikan fungsi sendi pinggul. Akan tetapi masa penggunaan implan THA terbatas, yakni setelah 10-20 tahun harus dilakukan pelapisan ulang. Sehingga terdapat ruang yang cukup luas untuk pengembangan desain implan yang akan bertahan lebih lama. Komponen utama dalam implan THA adalah acetabular cup, femoral head, dan femoral stem. Penelitian ini akan melibatkan beberapa model design femoral stem berbeda seperti lingkaran, elips, oval, dan trapesium untuk mengevaluasi tingkat kinerja dari setiap model yang dikembangkan dalam implan THA menggunakan finite element analysis (FEA). Pengujian dilakukan dengan dua variasi material berbeda untuk menentukan material yang paling kuat, yakni Co-Cr-Mo dan Ti-6Al-7Nb. Selain itu, pembebanan juga menggunakan dua variasi beban berbeda untuk memastikan implan kuat saat diberi pembebanan dari tubuh. Variasi pembebanan yang digunakan adalah 2300 N dan 3900 N. Pembuatan geometri dilakukan pada perangkat lunak Autodesk Fusion 360 serta pengujian finite element analysis (FEA) dilakukan pada ANSYS. Dari hasil penelitian, diperoleh bahwa bentuk trapesium menunjukkan performa terbaik karena deformasi dan tegangan yang paling rendah. Selain itu, CoCr Alloy lebih unggul dari pada Ti-6Al-7Nb karena nilai deformasi yang lebih rendah.

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The hip joint is a joint that connects the thigh bone (femur) with the hip bone (pelvis). These joints are susceptible to damage due to infection, accidents, torn cartilage, osteoarthritis, wear and tear, and bone degeneration. To overcome this problem, joint replacement surgery or Total Hip Arthroplasty (THA) can be performed, namely an implant to replace the damaged hip joint with an artificial joint. This is done to restore function of the hip joint. However, the period of use of THA implants is limited, namely after 10-20 years they must be resurfaced. So there is ample room for developing implant designs that will last longer. The main components in a THA implant are the acetabular cup, femoral head, and femoral stem. This research will involve several different femoral stem design models such as circular, elliptical, oval and trapezoidal to evaluate the performance level of each model developed in THA implants using finite element analysis (FEA). Tests were carried out with two different material variations to determine the strongest material, namely Co-Cr-Mo and Ti-6Al-7Nb. Apart from that, loading also uses two different load variations to ensure the implant is strong when subjected to load from the body. The load variations used were 2300 N and 3900 N. Geometry creation was carried out in Autodesk Fusion 360 software and finite element analysis (FEA) testing was carried out in ANSYS. From the research results, it was found that the trapezoidal shape showed the best performance because of the lowest deformation and stress. In addition, CoCr Alloy is superior to Ti-6Al-7Nb because of its lower deformation value."

"ABSTRAKDengan semakin berkembangnya metode soil improvement, khususnya denganmenggunakan Prefabricated Vertical Drain (PVD), maka diperlukan perhatiankhusus dalam menganalisa PVD. Pada umumnya kecepatan waktu konsolidasidipengaruhi oleh jarak dan panjang PVD. Analisa yang digunakan biasanyamenggunakan model konsolidasi 1 dimensi. Seiring perkembangan teknologikomputansi, perhitungan PVD dapat dilakukan dengan metode elemen hingga 3dimensi. Model 3 dimensi memiliki keakuratan yang baik namun tingkatkompleksitas yang lebih tinggi. Perhitungan PVD pada umumnya menggunakanmodel 2 dimensi / plane strain model. Agar model 2 dimensi memiliki keakuratanyang baik diperlukan ekivalensi permeabilitas tanah asli dan jarak PVD. Penulismenitikberatkan kedua hal tersebut dengan harapan diperoleh model yang tepatdalam perhitungan PVD sesuai dengan kenyataan di lapangan

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ABSTRACTWith the development of the soil improvement method, especially usingprefabricated vertical drain (PVD) it is necessary to analyize accurately. Generallythe rate of consolidation time depends on two factor, spacing and the length ofPVD. One dimension consolidation calculation is often used to analyze PVD.With development in computation technology, PVD calculation can be done byfinite element method three dimension which has good accuration but morecomplex. In fact, two dimension model used to calculate PVD in order to havegood accuration the permeability of soil and the spacing of PVD must beequivalent with three dimension model. Thw writer will focus in these factors inhopes to obtain the right PVD calculation model accordance with the fact in field;"

"ABSTRAKResistance spot welding (RSW) merupakan proses pengelasan yang sering digunakan untuk menyambung pelat logam umumnya pada industri otomotif dan penerbangan. Proses pengelasan RSW (Resistance Spot Welding) melibatkan fenomena kelistrikan, termal-mekanik, metalurgi, dan permukaan yang kompleks. Tidak seperti proses pengelasan lainnya, peristiwa terbentuknya sambungan las pada proses RSW terjadi sangat cepat (dalam mili-detik) dan mengambil tempat diantara benda kerja yang tumpang tindih satu sama lain. Simulasi pengelasan memungkinkan pemeriksaan visual terhadap sambungan las tanpa harus melakukan eksperimen yang mahal. Ukuran nugget las merupakan parameter yang paling penting dalam menentukan perilaku mekanik dari sambungan las RSW karena kualitas dan kekuatan sambungan las RSW secara dominan ditentukan oleh bentuk dan ukuran dari nugget las. Simulasi pemodelan proses pengelasan RSW dilakukan menggunakan modul ANSYS Parametric Design Language (APDL) berbasis metode elemen hingga (finite element method) yang tersedia, dalam ANSYS. Interaksi elektrikal dan termal dikembangkan untuk mempelajari pertumbuhan nugget pada pengelasan pelat aluminium A1100 dengan ketebalan masing-masing 0.4 mm. Dengan menggunakan pendekatan model simulasi ini, ukuran diameter nugget dapat diprediksi dengan baik melalui distribusi temperatur yang terbentuk selama proses pengelasan berlangsung. Pengelasan dilakukan dengan membuat variasi pada pemberian kuat arus (1kA dan 2kA) dan waktu pengelasan untuk masing-masing kuat arus yaitu 0.5, 1.0, dan 1.5 CT (cycle time). Diamater nugget untuk masing-masing parameter pengelasan yang didapat melalui simulasi pemodelan adalah, 4.276 mm, 4.372 mm, 4.668 mm, 5.616 mm, dan 5.896 mm. Pada spesimen dengan kuat arus 2 kA dan waktu pengelasan 1.5 CT, weld expulsion terjadi dan ditandai dengan menurunnya kekuatan tarik-geser dari spesimen tersebut dalam eksperimen.

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ABSTRAKResistance spot welding (RSW), generally which is one of the most often used to joint metal plate in the automotive and aviation industries. RSW welding process involves electrical, thermal-mechanical, metallurgy, and complex surface phenomenon. Unlike the other welding processes, weld joint formation in RSW process occurs very quick (in milli-seconds) and took place between the workpieces overlap each other. Welding simulation allows visual examination of the weld joint without having to perform an expensive experiment. Weld nugget size is the most important parameter in determining the mechanical behavior of welded joints in RSW process. The quality and strength of the weld joint in RSW process is predominantly determined by the shape and size of the weld nugget. Simulation modeling of RSW process performed using ANSYS Parametric Design Language (APDL) module based on the finite element method (FEM), embedded in ANSYS Workbench. Electrical and transient-thermal interaction was developed to study the weld nugget growth on resistance spot welding of aluminum A1100 metal plate with a thickness of 0.4 mm respectively. Weld nugget diameter can be well predicted by using this simulation model from the temperature distribution during the welding process. Welding is performed by varying the weld current (1 kA and 2 kA) and the welding time for each electric current which are start from 0.5, 1.0, and 1.5 cycle time. Nugget diameter for each of the welding parameters from the simulation modelling were 4,276 mm, 4,372 mm, 4,668 mm, 5,616 mm and 5,896 mm. Weld expulsion occurred for the specimen with welding current 2 kA and welding time 1.5 cycle time, characterized by the decreasing of the tensile-shear strength of the specimen."

"Concreteis a favoured building material due to its ease of productionand use. Even though the concrete mix isdesigned to have a uniform strength throughout the entire member, casting, aswell as the basic characteristics of the concrete materials, could yield anon-homogeneous constitution, resulting in a concrete strength gradation as afunction of the depth of the member. A functionally continuous and smooth strengthgradation of the concrete member along its axis or section is defined as gradedconcrete. The objective of this researchis to analyse the influence of two different concrete compressivestrengths that composed the gradedconcrete member. Thestudy is split into two parts: theexperimental work describing and identifying the mechanical properties offunctionally graded concrete and the finite element analysis implementing theseproperty variations in a model. The results showed that the concrete gradationinfluenced the ultimate strength of a member negatively and altered the stressdistribution and displacement response of the specimen."

"Studi numerikal dan parametrik dilakukan menggunakan ABAQUS pada sambungan spun pile - pile cap dengan beton pengisi bertulang serta perkuatan steel jacketing untuk menganalisis efektivitas confinement oleh steel jacketing. Studi eksperimen yang sebelumnya sudah dilakukan menunjukan steel jacketing masih belum mampu menghindari fenomena pinching dan tidak meningkatkan daktiltias secara signifikan. Efek confinement oleh steel jacketing akan ditinjau berdasarkan penurunan tegangan pada sengkang spun pile dan kenaikan kuat tekan beton inti spun pile. Studi parametrik dengan parameter koefisien friksi, tebal dan tinggi steel jacketing, serta beban aksial dilakukan untuk mendapatkan desain efektif dari perkuatan steel jacketing. Hasil pemodelan menunjukan bahwa penggunaan steel jacketing mampu memberikan efek confinement yang baik melalui penurunan stress development yang terjadi pada sengkang spun pile dan peningkatan beton inti spun pile. Desain efektif perkuatan steel jacketing yang disarankan adalah menggunakan zincalume tebal 1 mm dan tinggi 1,5D < H < 2D dimana D adalah diameter spun pile, untuk menghindari terjadinya local buckling pada zincalume.

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Numerical and parametric study was conducted using ABAQUS on a spun pile – pile cap connection filled with concrete reinforcement and steel jacket retrofitting to analyse the effectiveness of confinement by steel jacketing. Experimental study that has been conducted before shown that steel jacketing retrofitting wasn’t able to avoid pinching and didn’t significantly increase ductility. Confinement effect by steel jacket will be viewed based on the degradation of stress developed on spun pile’s stirrups and the enhancement of spun pile’s core concrete strength. Parametric study consisting of friction coefficient, thickness and height of steel jacketing, and axial load was conducted to achieve an effective design of steel jacket retrofitting. Modelling results shown that the use of steel jacket retrofitting was able to provide good confinement by reducing the stress development that occur on the spun pile’s stirrups as well as enhancement in spun pile’s core concrete strength. An effective design of steel jacketing retrofitting that was suggested is using a 1 mm in thickness zincalume and height of 1,5D < H < 2D, where D is the diameter of spun pile, to avoid local buckling on the zincalume."

"Concrete is a favoured building material due to its ease of production and use. Even though the concrete mix is designed to have a uniform strength throughout the entire member, casting, as well as the basic characteristics of the concrete materials, could yield a non-homogeneous constitution, resulting in a concrete strength gradation as a function of the depth of the member. A functionally continuous and smooth strength gradation of the concrete member along its axis or section is defined as graded concrete. The objective of this research is to analyse the influence of two different concrete compressive strengths that composed the graded concrete member. The study is split into two parts: the experimental work describing and identifying the mechanical properties of functionally graded concrete and the finite element analysis implementing these property variations in a model. The results showed that the concrete gradation influenced the ultimate strength of a member negatively and altered the stress distribution and displacement response of the specimen."