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All Journal Jurnal Rekayasa Material, Manufaktur & Energi Piston: Journal of Technical Engineering Jurnal Ilmiah Teknik Mesin "MEKANIK" IRA Jurnal Teknik Mesin dan Aplikasinya (IRAJTMA) IRA Jurnal Pengabdian Kepada Masyarakat Jurnal Polimesin
Mulyadi Mulyadi
Universitas Pembinaan Masyarakat Indonesia
Aerospace Engineering Automotive Engineering Control & Systems Engineering Education Electrical & Electronics Engineering Energy Engineering Industrial & Manufacturing Engineering Materials Science & Nanotechnology Mechanical Engineering Other

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ANALISA SIFAT MEKANIS KOMPOSIT EPOKSI/ PARTIKEL SILIKA DARI EKSTRAKSI SEKAM PADI (Bagian I: Eksperimental) Mulyadi, Mulyadi
MEKANIK: Jurnal Ilmiah Teknik Mesin Vol 5 No 1 (2019): Mei 2019
Publisher : Jurusan Teknik Mesin, Fakultas Teknologi Industri, Institut Teknologi Medan (ITM)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (599.032 KB)

Abstract

This work is focused on the effect of silica(silicon dioxide)on mechanical properties of modified epoxy resin. Eposchon A&B resin were utilised as a matrix to bind silica particles which were extracted from rice husk usingpyrolysis method. Eposchon A and Eposchon B were mixed with ratio 1:1. Silica with0, 2, 4 and 5% content by weight was introduced into Eposchon resin system. This composite mixtures were poured into silicon rhodorsil RTV mould to provide bending and fracture toughness coupon tests. The results revealed that bending strength of modified epoxy resin was improved by 14% for the maximum with 4% of silica content. On the other hand, fracture toughness were decreased as silica particles introduce into the epoxy system. Furthermore, fracture toughness enhanced as the content of silica higher up to 5%. It is concluded that silica from rice husk is potentials filler for polymer composite materials
Analisis Kegagalan Laminasi Komposit Epoksi/Serat Karbon Pada Sayap Pesawat Tanpa Awak Ansor Salim Siregar; Mulyadi Mulyadi; Syaiful Arief
Piston: Journal of Technical Engineering Vol 5, No 2 (2022)
Publisher : Prodi Teknik Mesin

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (8540.106 KB) | DOI: 10.32493/pjte.v5i2.18596

Abstract

This study aims to analyze the initial failure value using the Tsai – Wu criteria from the wing skin of an unmanned aircraft with the Eppler 214 airfoil model. The study was carried out using computer modeling with Abaqus software. The material used is an epoxy composite which is carbon fiber. The composites used in the wing skins have two different arrangement sequences, namely the fiber layer arrangement sequence 1 [00/900]8s and the layer sequence 2 [00/+450/-450/900]2s. The load given to the wing is a pressure of 0.40077 MPa. The results for the fiber layer sequence 1 [00/900]8s at the maximum stress distribution are 5.067 x 104 MPa and in the fiber layer sequence, 2 [00/+450/-450/900]2s the maximum value is 4.205 x 104 MPa. While the sequences consist of fiber layer 1 and layer 2 sequence layers, the Tsai – Wu failure meets the Tsai – Wu failure criteria because almost all of them fail
Studi Awal Pemodelan Aerodinamika Sayap Pesawat Tanpa Awak Kecepatan Rendah Mulyadi Mulyadi; Tony Siagian
IRA Jurnal Teknik Mesin dan Aplikasinya (IRAJTMA) Vol 2 No 2 (2023): Agustus
Publisher : CV. IRA PUBLISHING

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.56862/irajtma.v2i2.60

Abstract

This research is a prelimenary study of unmanned aerial vehicle design process. The study is conducted to understand the effect of wing shape on pressure of  the  wing  surface and to analyse air flow model on the wing surface and surround it that is crucial for the next design step.  Finite element method has been performed with the aid of computer. Computational fluid dynamics was carried out by using Freecad 0.21 software comes with powerful  OpenFOAM® Computational Fluid Dynamics workbench. Straight, tapered and tapered-bend wing shape were simulated with 1000 mm in length and constructed according to NACA 6412 profile. Straight wing had mean chord length of 100 mm while tapered wings were 80-120 mm. Furthermore, 20 m/s of wing speed was involved in simulation with angle of attack of 2 degree. Modeling results were robustly managed by means of Paraview 5.5.2 software. Results revealed that maximum surface pressure was formed on leading edge with 190 Pascals on straight wing and 210 Pascals on tapered-bend wing. Laminar air flow along wing profile was discovered without any vortex shedding occurred after passing the trail edge surface. Finally, simulation results discovered that there is a pressure difference on the top and bottom part of the wing. As the result, lifting force was created as expected.
The Effect of Adding Aluminum Scrap to Motor Vehicle Mufflers to Reduce the Danger of Exhaust Emissions Ahmad Marabdi Siregar; Chandra Amirsyahputra Siregar; Khairul Umurani; Mulyadi Mulyadi; Tony Siagian; ML Teguh Samudra; Aufa Afika
Jurnal POLIMESIN Vol 21, No 1 (2023): February
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30811/jpl.v21i1.3263

Abstract

Air pollution due to motor vehicle exhaust emissions is increased. Polluted air harms human health dan the environment. Consequently, it is essential to make a sustained effort to reduce air pollution. The purpose of this research is to investigate the effect of adding aluminum scrap to the exhaust system of a motor vehicle on gas emissions composition. The motor vehicle exhaust system was modified to accommodate aluminum scrap placement. A gas analyzer was utilized to observe exhaust gas composition, such as carbon dioxide, hydrocarbon, and carbon monoxide.  Aluminum scrap with different masses was wrapped around the exhaust's inner tube in 50 gr, 70 gr and 90 gr. The engine speed was maintained at 500 rpm throughout the testing process. It was found that the temperature of the outer exhaust tube is in a range of 40 degrees Celsius to 50 degrees Celsius. The results revealed that the most appropriate amount of aluminum scrap was 90 gr n to reduce carbon monoxide, hydrocarbon, and carbon dioxide in an exhausts gas. The surprising outcome was 76.78 % of carbon monoxide content declined, and furthermore hydrocarbon, and carbon dioxide content were deteriorated by 61.63% and 78.37%, respectively
Penambahan Sensor Arduino Uno Pada Mesin Perajang Singkong dan Pisang Berkapasitas 60 kg/Jam Fadillah, Muhammad Afif; Siregar, A Marabdi; ., Mulyadi; Sembiring, Jesayas
Rekayasa Material, Manufaktur dan Energi Vol 7, No 2: Juli 2024
Publisher : Fakultas Teknik UMSU

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30596/rmme.v7i2.17849

Abstract

In the industrial world, machines are widely used to facilitate a more effective and efficient way of working, by trying to abandon old work patterns that rely heavily on human labor along with the development of industrial technology 4.0 in observations made by researchers at household MSMEs in the snack food industry, in Titi Village Payung, Air Putih District, Batu Bara Regency. Processors of cassava and banana chips still use human power and use simple tools. The process of chopping cassava and banana chips is not done at a table, but is done directly on the floor. The chopping process in this condition causes an uncomfortable working position for the worker, because it is done with a bent back position, the head is always bowed and the legs are always bent. . This chopping process is usually carried out for 8 hours per day. The cassava and banana chopper tool at the research site's MSMEs has dimensions of 30 cm long, 15 cm wide and 21 cm high. On this basis, researchers consider it necessary to minimize the obstacles faced by cassava and banana chip managers, by making a cassava and banana chopping machine. The performance test results of the cassava and banana chopping machine obtained 1 kg of cassava and banana slices in 1 minute or the same as 60 kg in 60 minutes, with the resulting cassava and banana slices having a thickness of 1 - 2 mm. This cassava and banana chopping machine has been made to be more practical to use and can compete with domestically made products.
Tensile Modeling Of Composite Epoxy Modified With Nanosilica Particles ., Mulyadi; Siregar, A M
Rekayasa Material, Manufaktur dan Energi Vol 8, No 1: Januari 2025
Publisher : Fakultas Teknik UMSU

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30596/rmme.v8i1.22547

Abstract

The addition of nanosilica particles can enhance mechanical properties of epoxy based composite materials. Tensile behavior is very crucial properties to be investigated due to its appearance frequently in the application. The amount of nanosilica (SiO2) particles was added in 2%, 5%,8 % and 10% of weight to epoxy resin Epikote 828. Dogbone tensile specimens of epoxy modified with nanosilica were tested using universal tensile machine. The results of tensile properties were further elaborated using available analytical model and finite element analysis. Analytical model and finite element analysis using computer can cut the time to market. As the result, the cost can be minimized  compare to experiment based assessment. Tensile behavior improvement is revealed as the nanosilica particles added. A very good correlation among the results from experiment, analytical and finite element analysis has been revealed. 
Asesmen Model dan Struktur Rumah Prafabrikasi Tahan Gempa Untuk Korban Bencana Indonesia Mulyadi Mulyadi; Sheila Hani
IRA Jurnal Pengabdian Kepada Masyarakat (IRAJPKM) Vol 4 No 1 (2026): April
Publisher : CV. IRA PUBLISHING

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.56862/irajpkm.v4i1.394

Abstract

Indonesia is highly vulnerable to natural disasters, particularly earthquakes, tsunamis, and landslides, which frequently cause severe infrastructural damage and widespread displacement. The provision of post-disaster emergency housing is often constrained by time limitations, budget constraints, and construction standards. This study assesses whether earthquake-resistant prefabricated houses produced by Kinghouse Modular House Technology Co., Ltd., Guangzhou, China, are suitable for Indonesia’s geographical and social conditions and its building standards (SNI 1726:2019). The methodology encompasses coordination, literature reviews, direct observation of the production process, technical analysis of design and structure, and the formulation of adaptation recommendations. The assessment results indicate that the Kinghouse modular house—utilizing a galvanized C-channel steel frame, EPS sandwich panels, bolted connections, and anti-corrosive roofing—offers key advantages, including a lightweight structure and ease of assembly, making it highly feasible for implementation in disaster-prone areas. The primary recommendations include design modifications to align with national standards, material adjustments for tropical climates, and the development of multifunctional modular units. This study provides technical and strategic contributions for the government, industry, and the community in procuring rapid, safe, and sustainable post-disaster housing.
Design Modification and Strength Analysis of a Bearing Housing Using Finite Element Method Mulyadi Mulyadi; Bobby Umroh; Hendery Dahlan
Rekayasa Material, Manufaktur dan Energi Vol 9, No 2: JULI 2026
Publisher : Fakultas Teknik UMSU

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30596/rmme.v9i2.31605

Abstract

Bearing housings are critical mechanical components in small-scale manufacturing machinery. In field operations, standard pillow block designs frequently experience premature structural failures such as material cracking and high deformation under dynamic loads. This study aims to determine the exact structural causes of failure in standard bearing housings used within chain transmission systems and to develop an optimized, structurally superior modified design. The investigation was conducted numerically using open-source tools: FreeCAD for three-dimensional parametric modeling and PrePoMax (CalculiX solver) for Finite Element Analysis (FEA). The component was modeled using ASTM Class 35 Cast Iron with a yield strength of 170 MPa. The loading condition simulated a 1 HP motor running at 1500 rpm with a generated torque of 1.59 kg·m, where the chain tensile force was applied directly to the housing bore. The initial simulation revealed that the baseline design suffered from high stress concentrations around the bolt hole and fillet regions due to insufficient material thickness. The maximum principal stress reached 107.4 MPa, yielding an inadequate safety factor of 1.6 and a displacement of 0.002 mm. To resolve this, structural modifications were implemented by adding reinforcing ribs and thickening the housing profile. The FEA results of the modified design showed a significant stress reduction to 55 MPa (a decrease of approximately 49%). Furthermore, the maximum displacement at the top section dropped to 0.0009 mm, demonstrating a 45% reduction in displacement and higher structural stiffness. Consequently, the safety factor increased substantially from 1.6 to 3.6 (simulated at 3.09 in direct stress ratio). The incorporation of strengthening ribs and wall thickening successfully redistributes operational loads and minimizes material distortion. The modified design satisfies industrial safety regulations and is highly feasible for implementation in small-scale industrial chain drive applications.Keywords: Bearing Housing, Finite Element Method, Stress Concentration, Reinforcing Ribs, Safety Factor.
Co-Authors Ahmad Marabdi Siregar Ansor Salim Siregar Aufa Afika Bobby Umroh Chandra Amirsyah Putra Siregar Fadillah, Muhammad Afif Hendery Dahlan, Hendery khairul umurani ML Teguh Samudra Sembiring, Jesayas Sheila Hani . Siregar, A M Siregar, A Marabdi Syaiful Arief Tony Siagian