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PENGARUH WAKTU AGING TERHADAP KEKERASAN DAN STRUKTUR MIKRO KOMPOSIT Al-Si-Mg/Al2O3 DENGAN METODE STIR CASTING Junus, Salahuddin; Zulfia, Anne; Melisa, Melisa; Mariani, Lilis
ROTOR Vol 7, No 2 (2014)
Publisher : ROTOR

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (237.589 KB)

Abstract

Aluminum composite needs proper aging period to achieve its optimum mechanical properties through  precipitation hardening process. In this research, alumina (Al2O3) particulate reinforced aluminum alloy 6061 composite which is fabricated by stir casting method, undergoes T6 treatment in 175°C for 2 hours, 4 hours, 6 hours, and 8 hours. Mechanical properties evaluations such as tensile testing, hardness testing,  and wear rate testing; also microstructure and SEM observation are conducted. Research shows that the  optimum  artificial aging period for the aluminum composite is 6 hours in 175°C. Wear rate decreases after T6 treatment  applied. Hardness  increases after T6 treatment applied with aging period of 4 and 6 hours. Tensile strength decreases compared to as-cast composite due  to  formation  of  void  at  interface  when T6 treatment conducted. Manufacturing factors will affect the mechanical properties of composite. Keywords: Aluminum composite, billet Al.6061, T6, aging period, stir casting
Model Predictive Control in Hardware in the Loop Simulation for the OnBoard Attitude Determination Control System Irwanto, Herma Yudhi; Yusgiantoro, Purnomo; Sahabuddin, Zainal Abidin; Bura, Romie O.; Artono, Endro; Hakim, Arif Nur; Nuryadi, Ratno; Andiarti, Rika; Mariani, Lilis
Journal of Robotics and Control (JRC) Vol 5, No 2 (2024)
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/jrc.v5i2.21613

Abstract

Rocket flight tests invariably serve a purpose, one of which involves area monitoring or aerial photography. Consequently, the rocket necessitates the installation of a camera that remains consistently oriented toward the Earth's surface throughout its trajectory. Thus, ensuring the rocket's stability and preventing any rotation becomes imperative. To achieve this, the Onboard Attitude Determination Control System (OADCS) was researched and developed, fully controlled by NI myRIO with Labview as the programming language, ensures the rocket's attitude control and maintains a rolling angle of 0 degrees during flight. The MyRIO oversees the retrieval of attitude and position data from the X-Plane flight simulator, offering feedback through actuator control. The development of the OADCS proceeded incrementally through stages utilizing the Software in the Loop Simulation (SILS) and Hardware in the Loop Simulation (HILS) techniques, to ensure the verification of the system's functionality before its application to the rocket for real flight testing. In the OADCS control scheme, Model Predictive Control (MPC) is chosen, and it is compared with a PID controller to serve as a benchmark for processing speed. Because the rocket's flight time is short and its speeds of up to Mach 4. The simulation results indicate that MPC can halt the rocket's rotation 12 times more rapidly than PID control. Additionally, the MPC's ability to maintain a zero-degree rotation can persist throughout the rocket's flight time. Employing SILS and HILS enhances the OADCS rocket development process by incorporating MPC, which holds promise for application in real rockets.
Stress Analysis of Load Cell Adaptor Designs For The Caliber450mm Solid Rocket Motor Static Test Moranova, Starida; Putro, Idris Eko; Abrizal, Haryadi; Mariani, Lilis; Prianto, Bayu; Hanif, Azizul; Andiarti, Rika; Ekadj, Firza Fadlan
Indonesian Journal of Aerospace Vol. 21 No. 2 (2023): Indonesian Journal Of Aerospace
Publisher : BRIN Publishing

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55981/ijoa.2023.2669

Abstract

This study presents a structural analysis of two load cell adaptor designs for a caliber-450 mm solid rocket motor. The structural analysis of a C-shape load cell adaptor and the newly designed truncated-cone shape is presented incorporates a 30-degree truncated disc section and varies the thickness to 30 mm, 25 mm, and 20 mm. The numerical simulation using PATRAN reveals that by altering the arm thickness while maintaining the constant hinge thickness, the 30 mm thickness in the disc section yields the best local maximum stress. However, considering the global maximum stress, the 25 mm thickness emerges as the optimal design. The simulation results show that the 25 mm disc section of the load cell adaptor surpasses the aerospace standard safety factor (SF = 1.5) for both local and global maximum stress.
DESAIN DAN PEMBUATAN NOSEL DENGAN BLAST TUBE DENGAN METODE SHRINK-FIT Robertus Heru T; Mariani, Lilis
Indonesian Journal of Aerospace Vol. 7 No. 2 (2009): Jurnal Teknologi Dirgantara
Publisher : BRIN Publishing

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Abstract

Makalah ini membahas tentang desain struktur, pembuatan dan pengujian nosel roket yang menggunakan blast tube. Blast tube ditempatkan pada nosel motor roket untuk memberikan ruang yang aman bagi komponen elektronik kendali yang berada di ekor roket. Karena geometrinya kompleks, komponen-komponen struktur dari nosel dibagi menjadi beberapa bagian. Grafit dipilih sebagai bahan ablatif untuk blast tube dan nosel. Metode shrink-fit digunakan untuk menyatukan grafit dengan struktur logamnya. Anyaman serat kaca digunakan untuk bahan insulasi pada bagian luar blast tube dan nosel, karena diperkirakan suhunya masih terlalu panas untuk komponen elektronik sistem kendali yang terbuat dari plastik. Uji tekanan hidrostatis dilakukan untuk melihat tekanan maksimum yang bisa ditahan blast tube. Uji penyalaan statik dilakukan untuk memvalidasi desain propulsi dan melihat apakah struktur nosel dapat bertahan seperti prediksi. Hasil test menunjukkan bahwa blast tube dapat menahan tekanan dan suhu selama penyalaan. Namun, modifikasi perlu dilakukan di bagian divergen untuk menghindari terlepasnya grafit, seperti yang terjadi saat uji statik.