cover
Article Per Year (5 Year)
All
Home Page
OAI Link
Editorial Team
Contact
Reviewer
Google Scholar
Contact Name
Dharu
Contact Email
dharufs@staff.uns.ac.id
Phone
+6281217717892
Journal Mail Official
mesin@ft.uns.ac.id
Editorial Address
Jl. Ir. Sutami no 36 A, Building I, Faculty of Engineering, Universitas Sebelas Maret, Surakarta
Location
Kota surakarta,
Jawa tengah
INDONESIA
Mekanika: Majalah Ilmiah Mekanika
Published by Universitas Sebelas Maret
ISSN : 14127962     EISSN : 25793144     DOI : https://doi.org/10.20961/mekanika
Core Subject :
"Mekanika: Majalah Ilmiah Mekanika" is an open-access journal published by Mechanical Engineering Study Program, Faculty of Engineering, Universitas Sebelas Maret. Mekanika invites scholars, researchers and practioners who have interest in mechanical engineering to publish their articles and also provides forums for them to share their works and knowledge. Mekanika focuses on the area of materials engineering and science, design, energy, manufacturing and construction but is not limited to. Both English and Bahasa are accepted in this journal. Mekanika has two issues every year (March and September) and aims to publish more frequently in the future.
Arjuna Subject : Teknik (semua kategori) - Teknik Mesin
Articles 91 Documents
 6   7   8   9   10 
Failure Criteria in Crashworthiness Analysis of Ship Collision and Grounding Using FEA: Milestone and Development Hermes Carvalho; Ridwan Ridwan; Sudarno Sudarno; Aditya Rio Prabowo; Dong Myung Bae; Nurul Huda
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 DNV RP-C204 criterion, Germanischer Lloyd criterion, Peschmann, RiceTracey 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.
Effect of Adding Al2O3 on the Macrostructure of Friction Stir Welding Polypropylene Sheet Dinda Clara; Frantisek Miksik; Bambang Kusharjanta; Triyono Triyono; Aniddya Salsabila Kurnia Putri
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.v22i1.63026

Abstract

In this study, an experimental investigation has been carried out to determine the effect of alumina (Al2O3) addition in joining polypropylene. Polypropylene is a thermoplastic material used most as a non-metallic material. One of the joining methods that can be applied in Polypropylene is Friction Stir Welding (FSW). The use of Al2O3 as a filler is to modify the polypropylene matrix's properties to improve the joint's quality. The Al2O3 powder with 99 9% purity was inserted along the polypropylene plates in the groove. This research analyzed the role of adding Al2O3 and tool rotation speed concerning the joints' quality. The experiment was performed under different values of tool speed rotation (204 rpm, 356 rpm, 620 rpm, and 1140 rpm) and the presence or absence of the addition of alumina powder. Then, the joint's quality is visually observed by optical macroscopy at the top and cross-section view. From macroscopic observations, adding alumina could make the visual of the joint look better and result in minimum defects than the joint without alumina addition. Instead, the increasing tool speed rotation helped the distribution of alumina during the welding process.
Design Analysis and Structural Prediction of Bus Driver Chair Support: A Study Case using HOQ and FEM Joung Hyung Cho; Ridwan Ridwan; Rama Panji Kusuma; Joko Triyono; Nurul Muhayat; Aprianur Fajri; Fajar Budi Laksono
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.v22i1.44371

Abstract

The bus driver's comfort is crucial. The location of the driver's seat, which is correlated with the seat support design, is one of the elements supporting his comfort. The bus business chosen as a representative is PT Selamet Trans Abadi, which has its headquarters in Pati City, Central Java. By considering the Safety Factor, House of Quality (HOQ), weight, shape, and seat support dimensions, this study intends to ascertain how the characteristics of the bus seat support form after receiving a load or force. Conducting a field visit to gather the necessary data is the initial step in this research. The following stage is to decide on the design criteria based on the collected data. Next, use Solidwork to model the design. Using the Finite Element Method (FEM), this program can investigate design characteristics. The loading simulation under consideration includes clutch engagement, bus brake application, and clutch engagement, whether the support is static or stationary. The validation with two supporting journals is then run as the following step to validate the findings. The constant chair support fulfills the typical value, according to the study's findings, whereas support 1 is the most fracture-prone. The outcomes of supports 2 and 3 demonstrate that the support strength is weak since it is subjected to an unequal load.
Mechanical Properties Of Pack Carburized AISI 4340 With Variation Energizer Composition of Barium Carbonate (BaCO3) And Sodium Carbonate (Na2CO3) Agris Setiawan; Sapna Yusmania; Anton Sudiyanto
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.v22i1.63870

Abstract

The aim of this research was to determine the mechanical strength of AISI 4340 steel after pack carburizing with variation of barium carbonate (BaCO3) and sodium carbonate (Na2CO3) as energizer. The various ratios of energizer: 40/60, 50/50 and 60/40 w/w%. Mechanical test was conducted to determine tensile (ASTM E-8), impact charpy strength (ASTM E-23), rockwell hardness number (ASTM E-18) and microstructure characterization (ASTM E-3). Both type specimens were temperature pack carburized is 950ºC and holding time is 3 hours.  Results showed that specimen C has a lowest ultimate tensile strength mean values than the other specimens, which is 333.43±30.22 MPa. The results of the impact test showed that the lowest impact energy value is found in specimen C, which is 4.32 joules and the highest impact energy value is found in specimens without treatment, which is 15.80 joules. Based on microscope observation indicated that microstructure of specimen was martensite structure increase and the results of the hardness test was influenced by martensite phase, specimen C has the highest hardness compared to other specimens, which is 80.70 HRC while the untreated specimen is 56.90 HRC.
Effect of Screw Rotation Speed on Mechanical Properties and Morphology of Abs/Mcc Composites Irvian Adhana; Dharu Feby Smaradhana; Dody Ariawan; Wijang Wisnu Raharjo; Burhanuddin Yusuf
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.v22i1.70884

Abstract

Acrylonitrile Butadiene Styrene (ABS) polymer is an example of a thermoplastic polymer that requires heat in its production process. ABS polymer also can be modified to increase strength against resistance, toughness, and heat resistance by adding MCC as a reinforcement to ABS composites. Extrusion is one of the established methods of polymer processing with filler and consequently disperses filler inside the polymer. Different speed shows different behavior of filler dispersion. Therefore, this study was conducted to know the effect of extruder screw speed variations on the mechanical, physical, and thermal stability of ABS/MCC composites. The compositions used in producing ABS/MCC composites are 96% for ABS and 4% for MCC. The production process uses screw extruder speed variations of 10 rpm, 15 rpm, and 20 rpm. ABS/MCC composite in the barrel and hot press use 160 °C for the temperature process. The highest tensile strength was obtained at 10 rpm variation for 14.2 MPa. Increasing the speed of the extruder screw causes a decrease in MCC content attached to ABS which reduces the mechanical strength. ABS/MCC composite density value decreased with the increased extruder speed, as evidenced by the increasing number of voids formed based on SEM testing.
Evaluating the Influence of Environmental Factors and Parameters on Advancements in Welding and Joining Processes: A Review Sudarno Sudarno; Quang Thang Do; Haris Nubli; Dandun Mahesa Prabowoputra; Nur Candra Dana Agusti; Ridwan Ridwan; Anggi Vandika
Mekanika: Majalah Ilmiah Mekanika Vol 22, No 2 (2023): MEKANIKA: Majalah Ilmiah Mekanika
Publisher : Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/mekanika.v22i2.75378

Abstract

This review article presents a comprehensive overview of welding, including its environmental influence, common welding failures, welding parameters, and predictions of development regarding welding and corrosion. The quality and integrity of welds can be significantly affected by environmental factors such as temperature, humidity, and atmospheric contaminants. Moreover, welding failures can occur due to various reasons, such as improper welding techniques, inadequate preparation, corrosion, or material defects, leading to structural weaknesses and compromised joint integrity. Furthermore, notable progress has been achieved in welding system technology, encompassing automation, robotics, and real-time monitoring. These advancements underscore the vital role of welding parameters in transforming control, precision, and productivity within the welding process. The integration of innovative welding systems has led to improved welding efficiency, reduced human error, and increased overall process reliability. This review consolidates knowledge from diverse sources, making it a valuable resource for researchers, practitioners, and industries involved in welding.
Repair Project Acceleration Strategy of Three Ship Units using Fuzzy Logic Analysis and Critical Path Method Hidayatus Ubyani; Tuswan Tuswan; Hartono Yudo; Haris Nubli; Ocid Mursid; Muhammad Iqbal
Mekanika: Majalah Ilmiah Mekanika Vol 22, No 2 (2023): MEKANIKA: Majalah Ilmiah Mekanika
Publisher : Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/mekanika.v22i2.76502

Abstract

The project planning process, especially in ship repair projects, is essential to improving project completion. Ineffective planning of ship repair projects results in a lack of time and labour efficiency. Therefore, using project acceleration tools in scheduling ship repair activities is crucial to accelerate project completion and mitigate risk analysis of delays for each project activity. This research uses the critical path method (CPM) to analyze the main schedule of three combined ship repair projects. Then, shop-level planning is used to determine the productivity of each workshop so that each workshop knows the volume of work that needs to be completed daily. Furthermore, fuzzy logic is applied to analyze the risk of delays in repair project activities. The addition of working hours to critical work activities is accelerated from 30 days, the normal duration, to 23 days. Meanwhile, the addition of the workforce to critical work activities is accelerated from 30 days, the normal duration, to 22 days. The analysis of productivity values in each workshop results in the following productivity values: sandblasting and painting workshop 309.97 m2/person-days, piping workshop 4.12 units/person-days, fabrication workshop 407.16 kg/person-days, outfitting workshop 14.8 units/person-days, tank cleaning workshop 114.36 m3/person-days, and machining workshop 2.7 units/person-days. The fuzzy logic analysis results to determine the risk of delays in critical activities show that jobs with the codes SP1, SP2, SP3, SP4, M2, and SP5 have a high risk of delay. Additionally, the collaboration with other departments in the company, such as the marketing, finance, and human resources departments, is ongoing to complete assigned tasks.
Adsorption Characteristics of Silica Gel-Water Pairs in Personal Protection Equipment Shazia Hanif; Suryadijaya Adiputra; Indri Yaningsih; Eko Prasetya Budiana
Mekanika: Majalah Ilmiah Mekanika Vol 22, No 2 (2023): MEKANIKA: Majalah Ilmiah Mekanika
Publisher : Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/mekanika.v22i2.71250

Abstract

The utilization of RD-type silica gel material as an adsorbent within the Personal Protective Equipment (PPE) layer underwent a comprehensive analysis aimed at elucidating its unique adsorption characteristics through the application of MATLAB programming. This study aims to determine the characteristics of silica gel RD to water vapor in terms of adsorption capacity and rate. A layer modeling approach was employed to simulate the Personal Protective Equipment (PPE), which comprised four distinct layers: the surrounding environment air, the fabric layer, the RD-type silica gel layer, and the air gap separating the silica gel from the skin surface. The simulation encompassed environmental conditions set at 27℃, while the human body's temperature was maintained at 35℃. This study uses a simulation method using GAB (Guggenheim–Anderson–de Boer) modeling calculations to determine isothermal characteristics and LDF (Linear Driving Force) modeling to determine kinetic characteristics with an adsorbent temperature of 26.84℃. The simulation results show that the isothermal characteristics of silica gel RD at a relative humidity of 60% or a relative pressure of 0.6 have an absorption capacity of 0.38 kg/kg. Moreover, the kinetic characteristics of silica gel RD have an absorption rate of 0.38 kg/kg of water vapor with a time of 980 s until a significant reduction in the absorption value occurs.
Numerical Analysis of Openings in Stiffeners under Impact Loading: Investigating Structural Response and Failure Behavior Ridwan Ridwan; Sudarno Sudarno; Haris Nubli; Achmad Chasan; Iwan Istanto; Pandu Sandi Pratama
Mekanika: Majalah Ilmiah Mekanika Vol 22, No 2 (2023): MEKANIKA: Majalah Ilmiah Mekanika
Publisher : Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/mekanika.v22i2.76774

Abstract

As the demand for lightweight ships continues to rise, there is a growing necessity to explore innovative methods that can reduce the weight of ship structures without altering the materials used. This research addresses this challenge by investigating the effect of opening in stiffener under impact loading. The research aims to provide valuable insights into optimizing weight reduction strategies while ensuring the ship's overall strength and performance remain uncompromised. To achieve this goal, the study employed the finite element method as a solver. By simulating impact scenarios and analyzing stiffener responses, the numerical analysis quantified the structural behavior and failure modes. The focus was on understanding the impact of openings on the structural integrity and how it relates to their positioning relative to the impact point. The results of the study indicate that opening slightly distant from the impact point exhibit greater strength, showcasing a counterintuitive relationship between opening placement and structural response.
Effect of Hole Geometry Shape in Vortex Generators on Fluid Output Temperature: Computational Fluids Dynamics Validation Mohd Afzanizam Mohd Rosli; Singgih Dwi Prasetyo; Dominicus Danardono Dwi Prija Tjahjana; Alfian Fahrul Yuliansyah; Zainal Arifin
Mekanika: Majalah Ilmiah Mekanika Vol 22, No 2 (2023): MEKANIKA: Majalah Ilmiah Mekanika
Publisher : Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/mekanika.v22i2.71340

Abstract

Several methods to enhance heat transfer can be classified into three categories: active, passive, or hybrid. Among these methods, Vortex Generators (VGs) are one passive heat transfer enhancement device widely used in heat exchangers. This study aims to explore the geometric shapes of VGs equipped with longitudinal holes and examine their influence on the outlet temperature of the fluid. For the analysis in this research, a three-dimensional Computational Fluid Dynamics (CFD) simulation using ANSYS Fluent software was employed. The increased heat transfer and flow resistance in the VG geometry were evaluated based on previous research for validation. The study results demonstrate that the simulation produces fluid outlet temperature values and velocity contours that closely resemble the results obtained from the reference study. The validation error of this research was found to be only 0.02%, indicating high-quality and accurate simulation results. Furthermore, the study compared various geometries of the VG holes in the system. Among these geometries, hexagonal-shaped VG holes exhibited high-velocity contours on the VG side while achieving the lowest fluid outlet temperature at approximately 303.53 K. The findings of this study serve as a basis for further developments in enhancing the efficiency and performance of heat exchangers using VGs.

Page 8 of 10 | Total Record : 91

 6   7   8   9   10 

Filter by Year

2017 2024


Reset
Filter By Issues
All Issue Vol 23, No 2 (2024): MEKANIKA : Majalah Ilmiah Mekanika Vol 22, No 2 (2023): MEKANIKA: Majalah Ilmiah Mekanika Vol 22, No 1 (2023): MEKANIKA: Majalah Ilmiah Mekanika Vol 21, No 2 (2022): MEKANIKA: Majalah Ilmiah Mekanika Vol 21, No 1 (2022): MEKANIKA: Majalah Ilmiah Mekanika Vol 20, No 2 (2021): MEKANIKA: Majalah Ilmiah Mekanika Vol 20, No 1 (2021): MEKANIKA: Majalah Ilmiah Mekanika Vol 19, No 2 (2020): MEKANIKA: Majalah Ilmiah Mekanika Vol 19, No 1 (2020): MEKANIKA: Majalah Ilmiah Mekanika Vol 18, No 2 (2019): MEKANIKA: Majalah Ilmiah Mekanika Vol 18, No 1 (2019): MEKANIKA: Majalah Ilmiah Mekanika Vol 17, No 2 (2018): MEKANIKA: Majalah Ilmiah Mekanika Vol 17, No 1 (2018): MEKANIKA: Majalah Ilmiah Mekanika Vol 16, No 2 (2017): MEKANIKA: Majalah Ilmiah Mekanika Vol 16, No 1 (2017): MEKANIKA: Majalah Ilmiah Mekanika More Issue