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Analysis of Tetrachiral Sandwich Structures at High-Velocity Impact: Influence of the Applied Material and Projectile Core Geometry Maulana, Sultan; Prabowo, Aditya Rio; Wibowo, Wibowo; Do, Quang Thang; Muttaqie, Teguh; Muhayat, Nurul; Fitri, Siti Nurlita
Civil Engineering Journal Vol 10, No 10 (2024): October
Publisher : Salehan Institute of Higher Education

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.28991/CEJ-2024-010-10-017

Abstract

This research involved ballistic impact analysis on a tetrachiral sandwich structure in which the shapes of the circular nodes in the tetrachiral core are modified into polygonal shapes, namely a square, hexagon, and octagon. The objectives of this study were to observe the effect of a modified sandwich tetrachiral structure core, investigate the effect of the projectile geometry, and calculate the material performance of the structure. This research was conducted using numerical analysis utilizing the finite element method. The simulation methodology was validated through a benchmarking study, the results of which showed an error below 6%. The findings show that the material with the best performance was Armox 500T, at 5033 J. The most difficult projectile to withstand was conical, followed by ogive, hemispherical, and blunt. The results of the core modification on the tetrachiral sandwich structure show that the octagonal core had better energy absorption, by 2.8%, compared to the circular core. Modifying the node geometry in the tetrachiral core and then analyzing it with stress and strain contours are the novel aspects of this research. Doi: 10.28991/CEJ-2024-010-10-017 Full Text: PDF
Glow-Wire Analysis of Polypropylene Blends for Mechanical and Marine Engineering Applications Firdaus, Himma; Supono, Ihsan; Pratama, Anandito Adam; Istanto, Iwan; Prabowo, Aditya Rio; Kusnandar, Nanang; Kasiyanto, Iput; Wijaya, Rahman; Lailiyah, Qudsiyyatul; Budiana, Eko Prasetya; Yaningsih, Indri; Akbar, Hammar Ilham; Imanullah, Fahmi
Civil Engineering Journal Vol. 11 No. 7 (2025): July
Publisher : Salehan Institute of Higher Education

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.28991/CEJ-2025-011-07-018

Abstract

Polymer materials are widely used due to their versatility; however, their vulnerability to fire is a significant concern, especially under electrical influences on engineered mechanical designs and marine structure applications. This study examines the fire resistance of a polypropylene (PP) blend using Glow-Wire Flammability Index (GWFI) and Glow-Wire Ignition Temperature (GWIT) tests. While previous research typically relies on flame-retardants to address flammability, this work proposes using a simple 1:1 weight ratio blend of two distinct PP types. This specific PP blend was selected to provide balanced material properties and improved processing consistency. The results from glow-wire tests were compared with previous findings to evaluate flammability performance. Our findings reveal that although the PP blend offers enhanced fire resistance compared to neat PP, it remains inferior to PP-containing flame-retardant additives. The outcomes suggest that this blended PP may be suitable for applications where mechanical properties, cost-effectiveness, and recyclability precede fire resistance, such as engineered automotive interiors, mechanical design of marine transportation, and low-risk electrical components in engineering infrastructure. This initial research contributes valuable insights into the fire behavior of PP blends. Moreover, it establishes a foundation for future investigations into polymer fire resistance, encouraging additional glow-wire testing on other polymer systems.
Peningkatan Prestasi Non-Akademik Siswa MAN 1 Surakarta melalui Pelatihan Kompetisi Robotika Unmanned Surface Vehicle Utomo, Fahri Setyo; Prabowo, Aditya Rio; Pranata, Aria; Istanto, Iwan; Wijaya, Rahman; Yaningsih, Indri; Susilo, Didik Djoko
Jurnal Pengabdian kepada Masyarakat Nusantara Vol. 6 No. 4 (2025): Edisi Oktober - Desember
Publisher : Lembaga Dongan Dosen

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55338/jpkmn.v6i4.6623

Abstract

Robotika merupakan bidang ilmu yang menggabungkan teknik, komputer, dan elektronika untuk menghasilkan mesin cerdas yang mendukung efisiensi kerja manusia. Madrasah Aliyah Negeri (MAN) 1 Surakarta telah menerapkan pembelajaran robotika melalui kelas tutorial, namun keterbatasan penguasaan dasar desain 3D, perancangan PCB, dan pemrograman masih menjadi kendala dalam pengembangan inovasi serta persiapan kompetisi. Tujuan program Pengabdian kepada Masyarakat ini adalah meningkatkan kompetensi siswa dalam bidang Unmanned Surface Vehicle (USV) melalui pelatihan desain 3D, perancangan sirkuit PCB, serta pemrograman berbasis Python. Metode kegiatan dilakukan dalam lima pertemuan yang meliputi sosialisasi, pelatihan mekanik, perakitan PCB, dan object detection berbasis machine learning. Data dikumpulkan melalui observasi, pre-test dan post-test, serta evaluasi praktik. Hasil menunjukkan peningkatan signifikan pemahaman siswa pada bidang desain 3D (52% menjadi 84%), elektronika dan PCB (47% menjadi 79%), serta pemrograman (49% menjadi 81%). Simpulan dari kegiatan ini adalah pelatihan ini memperkuat keterampilan teknis siswa dan mempersiapkan mereka menghadapi kompetisi robotika di tingkat nasional maupun internasional, serta memberikan model pembelajaran berbasis praktik yang dapat diadaptasi pada pendidikan menengah untuk mendukung inovasi teknologi.
Structural design analysis of sandwich panels under axial compression load: Utilization of geometry and material variations Alifianto, Muhammad Daffa; Rohman, Hamdani Maftuh; Pratama, Anandito Adam; Istanto, Iwan; Prabowo, Aditya Rio; Melnyk, Oleksiy; Do, Quang Thang; Muttaqie, Teguh; Budiana, Eko Prasetya; Sohn, Jung Min; Wijaya, Rahman
Kapal: Jurnal Ilmu Pengetahuan dan Teknologi Kelautan Vol 22, No 3 (2025): October
Publisher : Department of Naval Architecture - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/kapal.v22i3.75955

Abstract

This study aims to analyze the performance of sandwich cylindrical shell structures under axial compression load by varying the geometry and types of material. Numerical simulations were conducted using ABAQUS software, employing the finite element method (FEM) to evaluate von Mises stress, displacement, and energy absorption. The materials used include ASTM 1045, ASTM A36, and Mild Steel, with geometry designs varying across five different configurations. The simulation results indicate that the combination of material and geometry has a significant impact on the structural response of the sandwich cylindrical shell. ASTM 1045 exhibited the highest von Mises stress and displacement, indicating both high strength and substantial deformation, while Mild Steel demonstrated better elastic properties. Geometry 4 combined with ASTM 1045 proved to be the strongest configuration, while the combination of Geometry 1 and Mild Steel was the most elastic. This study contributes to the development of more efficient and impact-resistant ship structural designs. 
A comprehensive study of infrastructure failures in the energy industry to improve operational safety Ardyrizky, Dhanies Wahyu; Prabowo, Aditya Rio; Baek, Seung Jun; Do, Quang Thang
Jurnal Inovasi Mesin Vol. 7 No. 1 (2025): APRIL 2025
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/jim.v7i1.22583

Abstract

The demand for crude oil continues to increase in line with expanding needs, but this contrasts with its limited availability in nature. The oil and gas industry is one of the key sectors in the global economy, encompassing exploration, refining, processing, transportation, distribution, and sales. Given the high-risk working environment, safety is a crucial factor that must be considered. In recent decades, numerical methods have been widely used to enhance the effectiveness and efficiency of safety analysis, particularly in risk identification, equipment condition monitoring, and optimizing hazard mitigation strategies. This report discusses the application of numerical methods in improving the quality of planning, maintenance, and failure mitigation of various components and infrastructure at PT Pertamina Patra Niaga Fuel Terminal Boyolali. The study focuses on MOV with the friction coefficient between the stem and stem nut, pipeline systems concerning corrosion in elbows caused by chemical compounds carried by oil, and storage tanks related to temperature control within the tank to maintain the quality and quantity of oil as per demand. A comprehensive study shows that lubrication can limit the friction coefficient in MOV, while viscosity is a significant issue in pipeline systems and storage tanks. Numerical approach methods can improve the energy industry's safety, reliability, and efficiency. Modeling can reduce costs, time, and worker safety risks compared to experimental approaches.
Effect of Cu and SiO₂ on a Remelted-Recycled Piston Alloy Under Vertical Centrifugal Casting Conditions Triyono, Teguh; Surojo, Eko; Prabowo, Aditya Rio; Triyono, Triyono; Djordjevic, Branislav; Carvalho, Hermes; Adie, Prayoga Wira; Sholehuddin, Muhammad Ilham
Civil Engineering Journal Vol. 12 No. 1 (2026): January
Publisher : Salehan Institute of Higher Education

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.28991/CEJ-2026-012-01-020

Abstract

Functionally graded aluminum matrices produced by means of centrifugal casting offer a route to location-specific properties, yet sustainable feedstocks and dual-density reinforcements are less well explored. In this work, we evaluate vertical centrifugal casting (VCC) of a remelted, recycled piston alloy reinforced with silica (SiO₂) and copper (Cu) particulates selected for their contrasting densities relative to the matrix. Castings were produced at 1000 rpm for 5 minutes using a 500 °C preheated mold and an 800 °C pour temperature. Cu was added at 1–4 wt.% and SiO₂ was added at 0–9 wt.%. Bulk density/porosity measurements, Vickers hardness testing, and optical/SEM microstructural analysis were employed to characterize the resulting gradients. The density increased with the radial distance from the rotation axis, accompanied by a monotonic decrease in porosity, consistent with centrifugal separation. Microstructurally, SiO₂ concentrated toward the inner region near the rotation center; in comparison, Cu was enriched at the outer periphery. Correspondingly, hardness exhibited a spatial gradient: SiO₂-reinforced zones were hardest near the inner region, whereas Cu-rich outer zones were hardest at the external rim. These results demonstrate that VCC of a recycled Al–Si feedstock can be used to reliably tailor its microstructure and properties through density-driven particle segregation, enabling controllable, bidirectional functional grading using environmentally friendly starting materials.
Failure Criteria in Crashworthiness Analysis of Ship Collision and Grounding Using FEA: Milestone and Development Carvalho, Hermes; Ridwan, Ridwan; Sudarno, Sudarno; Prabowo, Aditya Rio; Bae, Dong Myung; Huda, Nurul
Mekanika: Majalah Ilmiah Mekanika Vol 22, No 1 (2023): MEKANIKA: Majalah Ilmiah Mekanika
Publisher : Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/mekanika.v22i1.70959

Abstract

This study presents reviews of the failure criteria to capture the resulting response due to the catastrophe of ship collision and grounding using the finite element. Researchers have introduced several failure criteria, for instance, the Det Norske Veritas (DNV) RP-C204 criterion, Germanischer Lloyd criterion, Peschmann, Rice-Tracey and Cockcroft-Latham (RTCL), Bressan-Williams-Hill (BWH) instability criterion, and Liu criterion. As in the mathematical formula, each criterion has a difference. The choice of failure criteria will depend on the simulation's specific requirements and the analysis's goals. Liu's criterion can be used to evaluate the failure of materials in ship collision simulations, for example, when large element sizes (i.e., 20 mm) are considered in the simulation.
Design of the Bengawan Unmanned Vehicle (UV) Roboboat: Mandakini Neo Nubli, Haris; Utomo, Fahri Setyo; Diatmaja, Hananta; Prabowo, Aditya Rio; Ubaidillah, Ubaidillah; Susilo, Didik Djoko; Wibowo, Wibowo; Muttaqie, Teguh; Laksono, Fajar Budi
Mekanika: Majalah Ilmiah Mekanika Vol 21, No 2 (2022): MEKANIKA: Majalah Ilmiah Mekanika
Publisher : Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/mekanika.v21i2.61624

Abstract

Mandakini Neo was made with the ship's capacity, speed, and comfort in mind, as well as the ship's hydrodynamic performance and construction cost. Therefore, the method used to determine the hydrostatic characteristics is through a simulation consisting of a resistance test, stability test, maneuver test, and seakeeping test. The simulation uses Maxsurf software with the Savitsky method, which is then processed by data. Global Positioning System (GPS) and ultrasonic sensor tests were also conducted. Based on the simulation results, the stability of the Mandakini Neo ship has a GZ value of 0.1417 m with an angle of 30°, which follows the standards of the International Maritime Organization (IMO). In testing, the maneuvers obtained have met IMO standards based on tactical and advanced diameters. Based on the seakeeping test, when the speed is 5 knots, the heave movement has the same magnitude for all wave headings, 0.0096 m. while the most considerable rolling motion is in the wave direction of 135°, which is 0.36 m, and the most considerable pitch motion is in the direction of the 180° wave, which is 0.042 m. At a speed of 10 knots, the heave motion produced is the same as for all wave headings.