Proof-Of-Concept of a Thermal Barrier Coated Titanium Cooling Layer for an Inside-Out Ceramic Turbine

Increasing turbine inlet temperature (TIT) of recuperated gas turbines would lead to simultaneously high efficiency and power density, making them prime candidates for low-emission aeronautics applications, such as hybrid-electric aircraft. The Inside-out Ceramic Turbine (ICT) architecture achieves high TIT by using compression-loaded monolithic ceramics. To resist inertial forces due to blade tip speed exceeding 450 m/s, the shroud of the ICT is made of carbon-polymer composite, wound around a metallic cooling ring. This paper demonstrates that it is beneficial to use a titanium alloy cooling ring with a thermal barrier coating (TBC), rather than nickel superalloys, for the interstitial cooling ring protecting the carbon-polymer from the hot combustion gases. A numerical Design of Experiments (DOE) analysis shows the design trade-offs between the minimum safety factor and the required cooling power for multiple geometries. An optimized high-pressure first turbine stage of a 500 kW microturbine concept using ceramic blades and a titanium cooling ring in an ICT configuration is presented. Its structural performance (minimum safety factor of 1.4) as well as its cooling losses (2% of turbine stage power) are evaluated. Finally, a 20 kW-scale prototype is tested at 300 m/s and a TIT of 1375 K during 4hrs to demonstrate the viability of the concept. Experiments show that the polymer composite was kept below its maximum safe operating temperature and components show no early signs of degradation.

Proof-Of-Concept of a Thermal Barrier Coated Titanium Cooling Layer for an Inside-Out Ceramic Turbine

Increasing turbine inlet temperature (TIT) of recuperated gas turbines would lead to simultaneously high efficiency and power density, making them prime candidates for low-emission aeronautics applications, such as hybrid-electric aircraft. The Inside-out Ceramic Turbine (ICT) architecture achieves high TIT by using compression-loaded monolithic ceramics. To resist inertial forces due to blade tip speed exceeding 450 m/s, the shroud of the ICT is made of carbon-polymer composite, wound around a metallic cooling ring. This paper demonstrates that it is beneficial to use a titanium alloy cooling ring with a thermal barrier coating (TBC), rather than nickel superalloys, for the interstitial cooling ring protecting the carbon-polymer from the hot combustion gases. A numerical Design of Experiments (DOE) analysis shows the design trade-offs between the minimum safety factor and the required cooling power for multiple geometries. An optimized high-pressure first turbine stage of a 500 kW microturbine concept using ceramic blades and a titanium cooling ring in an ICT configuration is presented. Its structural performance (minimum safety factor of 1.4) as well as its cooling losses (2% of turbine stage power) are evaluated. Finally, a 20 kW-scale prototype is tested at 300 m/s and a TIT of 1375 K during 4hrs to demonstrate the viability of the concept. Experiments show that the polymer composite was kept below its maximum safe operating temperature and components show no early signs of degradation.

Perancangan CNC Plasma Cutting Menggunakan Software Autodesk Inventor 2015

<p class="Abstract">This study aims to determine the frame safety factor and the precision level of CNC plasma cutting results. The research method used is a research and development model, namely the French model. This model has 8 steps that are used to produce a CNC plasma cut design. The data analysis technique used is descriptive statistical analysis techniques derived from the results of tests conducted. Safety factor testing was conducted using the 2015 Autodesk Inventor software with a frame of 110.54 N. The precision cutting results were carried out three times using the same instrument, 20 currents with a speed of 400 mm/min, against ST 37 material with a thickness of 1.3 mm. The results showed that the frame was categorized as safe because the minimum safety factor value was 4.23 ul and the cut test results showed an average measurement with a maximum deviation of 0.3 mm, so it could be concluded that plasma CNC cutting had tolerance. rate of ± 0.3 mm.</p>

Perancangan dan Analisis Tegangan pada Desain Footrest Sepeda Motor Menggunakan Autodesk Inventor

Motorbikes are widely chosen by the public as a mode of transportation in modern times, one of which is the automatic scooter type motorcycle. Visually, the matic scooter type motorcycle components have a nice and attractive shape, but this shape does not necessarily guarantee its safety. Not a few of these components have failed (broken) as happened to the footrest. Footrest is a component of a motorcycle vehicle that functions as a footrest for motorcycle passengers. Every different type of motorbike, the footrest shape is also different. The purpose of this study is to design a footrest design and analyze it with the help of software to obtain a footrest design that has a high safety factor value. The design of the motorcycle footrest design produces 3 different designs. The three designs were analyzed using the Autodesk Inventor 2017 software stress by providing a static load of 20 Kg and 90 Kg. From the analysis, the minimum safety factor value obtained from each footrest design against a load of 20 kg in design 1 is 13.42, design 2 is 5.7, and design 3 is 7.93. While the minimum safety factor value generated from each footrest design against a load of 90 kg in design 1 is 2.98, design 2 is 1.27, and design 3 is 1.76. Based on the results of the safety factor analysis carried out, the three designs are safe enough to withstand loads of 20 Kg and 90 Kg. But design 1 is safer because the resulting value of the safety factor is higher than the three designs, which is 2.98 to withstand a load of 90 Kg.

Analisis Stabilitas Lereng dengan Perkuatan Geocell Menggunakan Metode Elemen Hingga (PLAXIS 2D)

ABSTRAKLereng adalah permukaan bumi yang membentuk sudut kemiringan tertentu dengan bidang horizontal. Salah satu tindakan penanganan bencana longsor pada lereng melakukan perkuatan lereng menggunakan bahan geosintetik seperti geocell. Penelitian ini bertujuan untuk menganalisis pengaruh geocell terhadap kestabilan lereng, sehingga dapat diketahui karakteristik pemasangan geocell yang dapat meningkatkan faktor keamanan suatu lereng. Penelitian ini melakukan variasi jarak antar vertikal geocell dengan spesifikasi geocell dan data tanah yang telah didapatkan untuk dilakukannya tahap pemodelan dengan perkuatan geocell sampai mendapatkan nilai faktor keamanan lebih besar dari nilai faktor keamanan minimum. Pemodelan dilakukan menggunakan program PLAXIS 2D. Perkuatan dengan geocell efektif digunakan pada tanah lempung, sehingga pemasangan jarak vertikal geocell yang paling efektif terdapat pada jarak 1 meter berdasarkan panjang geocell 6 m, dengan kemiringan lereng 1:1, kuat tarik 14,5 MPa dan didapatkan nilai SF lebih besar dari /batas minimum, semakin rapat pemasangan geocell mampu meningkatkan nilai faktor keamanan dengan rata-rata sebesar 7%.Kata kunci: faktor keamanan, geocell, stabilitas lereng, timbunanABSTRACTSlope is the surface of the earth that forms a certain angle of inclination with a horizontal plane. One of the prevention to overcome landslides on slopes is to strengthen slopes using geosynthetic materials such as Geocells. This study aims to analyze the effect of geocells on slope stability, so that the characteristics of geocell installation can be known which can increase the safety factor of a slope. This study varies the distance between vertical geocells with geocell specifications and soil data that has been obtained for the modeling phase with geocell reinforcement to obtain the safety factor value greater than the minimum safety factor value. Modeling is done using 2D PLAXIS program. Reinforcement with geocells is effectively used on clay soils, so that the most effective vertical geocell spacing is at a distance of 1 meter based on the geocell length of 6 m, with a slope of 1: 1, tensile strength 14.5 MPa and the SF value is greater than / minimum limit, the denser the geocell installation can increase the value of the safety factor by an average of 7%.Keywords: safety factor, geocell, slope stability, embankment

Analisis Defleksi Pada Rangka Alat Pembuat Briket Sampah Organik

Rangka merupakan bagian yang paling penting dari sebuah konstruksi dimana kekuatan rangka sangat ditentukan dari bentuk dan dimensi. Kekuatan rangka pada konstruksi harus memenuhi aspek keamanan serta harus memperhatikan faktor kekuatan rangka itu sendiri. Menghitung kekuatan rangka dari alat pembuat briket sampah organik dilakukan dengan menggunakan cara simulasi untuk mengetahui kekuatan rangka dalam menerima beban. Simulasi yang dilakukan dengan menggunakan software SolidWorks 19 dengan pembebanan statis, dan dengan variasi beban 110 kg dan 4500 kg dengan menggunakan material baja tipe ASTM A36. Proses simulasi yang telah dilakukan dengan pembebanan 110 kg nilai tegangan maksimum sebesar 6.66046 N/mm2 (Mpa), nilai displacement maksimum sebesar 0.0114 mm, nilai strain maksimum sebesar 0.0000167973 mm, dan nilai safety factor minimal sebesar 38. Dengan pembebanan 4500 kg nilai tegangan maksimum sebesar 248.26596 N/mm2 (Mpa), nilai displacement maksimum sebesar 0.4231 mm, nilai strain maksimum sebesar 0.0006269075 mm, dan nilai safety factor minimal sebesar 1. Pembebanan 110 kg rangka masih dapat menahan beban dan nilai stress masih jauh dari standar yield strength material ASTM A36 sebesar 250 Mpa. Terdapat perubahan bentuk rangka saat dilakukan pembebanan tetapi masih bersifat elastis, pada pembebanan 4500 kg rangka tidak dapat menahan beban dan nilai stress mendekati standar yield strength material ASTM A36 sebesar 250 Mpa. Hasil simulasi menunjukkan bahwa rangka alat pembuat briket sampah organik dengan beban 110 kg dan dengan material Baja tipe ASTM A36 mampu menahan beban dengan lebih baik. Dibandingkan dengan beban 4500 kg dan dengan material yang sama. The frame is the most important part of a construction where the strength of the frame is very much determined from the shape and dimensions. The strength of the frame in construction must fulfill the safety aspect and pay attention to the strength factor of the frame itself. Calculating the strength of the frame from the organic waste briquette maker is done by using a simulation method to see the strength of the frame in receiving the load. Simulations carried out using solidWorks 19 software with static loading with a load variation of 110kg and 4500 kg using ASTM A36. The simulation process that has been carried out with a load of 110 kg with a maximum stress value of 6.66046 N / mm2 (Mpa), a maximum displacement value of 0.0114 mm, a maximum strain value of 0.0000167973 mm, and a minimum safety factor value of 38. At the load of 4500 kg the maximum stress value is 248.26596 N/mm2 (Mpa), the maximum displacement value is 0.4231 mm, the maximum strain value is 0.0006269075 mm, and the safety factor value is at least 1. A load of 110 kg the frame can still with stand the load and the stress value is still far from the standard yield strength material ASTM A36 of 250 Mpa. There is a change in the shape of the frame when it is charged but still elastic, at the load of 4500 kg the frame cannot with stand the load and the stress value is close to the standard yield strength material ASTM A36 of 250 Mpa. Simulation results showed that the frame of the organic waste briquette making tool with a load of 110 kg and with steel material type ASTM A36 is able to with stand the load better. Compared to a load of 4500 kg and with the same material.

Stability of Anchored Retaining Walls Under Seismic Loading Conditions to Obtain Minimal Anchor Lengths Using The Improved Failure Model

Anchored retaining walls are structures designed to support different loading applied in static and dynamic cases. The purpose of this work is to design and study the stability of an anchored retaining wall loaded with different seismic actions to obtain minimal anchor lengths. Mononobe-Okabe theory has been applied for the evaluation of seismic earth pressures developed behind the anchored wall. Checking the dynamic stability of anchored retaining walls is usually done using the classic Kranz model. To take into consideration the effects of the internal forces developed during failure, we have proposed a new model, based on the Kranz model, which will be used as the Kranz model to find the critical angle failure performed iteratively until the required horizontal anchor length is reached for a minimum safety factor. The results of this study confirm that the effect of the seismic load on the design of an anchored retaining wall, and its stability, has a considerable influence on the estimation of anchor lengths. To validate the modifications made to the new model, a numerical analysis was carried out using the Plaxis 2D software. The interpretation of the obtained results may provide more detailed explanation on the effect of seismic intensities for the design of anchored retaining walls.

Pengaruh Beban terhadap Prediksi Umur Fatik Rangka Meja Kerja Balai LAPAN Garut Menggunakan Ansys Workbench

The study examines the effect of the load on fatigue life prediction of a workbench frame using the finite element method. The design of the workbench frame uses Autodesk Inventor Professional 2017, while finite element analysis uses Ansys Workbench. The workbench frame is subjected to loads 150, 175, 200, and 225 kg with a fully-reserved type of loading. Fatigue life prediction using Gerber's mean stress theory. The material of the workbench frame using Aluminum alloy 6061. The simulation results show that the workbench frame has a minimum fatigue life for loads of 150, 175, 200, and 225 kg, respectively 1 x 108, 6.61 x 107, 1.69 x 107, and 4.09 x 106 cycles. Whereas the minimum safety factor for fatigue life is 150, 175, 200, and 225 kg, respectively 1.395; 1,196; 1,046; and 0.930. It shows the workbench frame can withstand the fatigue life to a minimum of 107 cycles for a load of 150, 175, and 200 kg because it has a safety factor of more than 1. While for the 225 kg load, the workbench frame fails to reach a minimum age of 107 cycles due to fatigue life prediction is only 4.09 x 106 cycles with a safety factor of less than 1, which is 0.930.

A Study on the Fatigue Strength of a Low-Speed Diesel Engine Connecting Rod Made of 42CrMoA

In recent years, diesel engine is developing rapidly in the direction of high power and super long stroke, which requires higher strength of its key moving parts. Connecting rod is one of the key moving parts of diesel engine which is subjected to complex alternating load during the working process. This loading condition has a great influence on its structural strength and reliability. In the proposed study, the strength and fatigue of a low-speed diesel engine con-rod made of 42CrMoA are analyzed. The 3-D model of the con-rod assembly built in the proposed study. The stress distribution and deformation of the con-rod assembly under the maximum explosive pressure are presented and studied. In the present paper, fatigue safety factor of all parts of con-rod assembly under the maximum explosive pressure condition is checked. According to the results carried out from the proposed work, the corresponding alternating stress is 340MPa, while the fatigue limit of 42CrMo material is above 430-540MPa, which means that the con-rod parts work under the alternating stress far below the fatigue limit. The kirasushvili method is adopted in the present paper as the standard of safety factor evaluation of con-rod. According to the allowable safety factor table of kirasushvili method, the minimum safety factor of the big and small ends of the con-rod and rod body can meet the requirements without fatigue damage.