METAL: Jurnal Sistem Mekanik dan Termal

Optimization of Hot Press Temperature and Eggshell Filler Composition in Biocomposite Fabrication Using the Taguchi Method

Intan Nazwa — 2026-05-25

The utilization of biomass waste as a reinforcing agent for biocomposites presents an attractive alternative in the development of environmentally friendly materials. This study aims to analyze the effect of varying percentages of chicken eggshell and crumb rubber fillers, as well as the hot press temperature, on the mechanical properties of the biocomposite, including the Modulus of Rupture (MOR), Modulus of Elasticity (MOE), and strain. The Taguchi method with an L9 orthogonal array design was employed to evaluate the effect of each factor and determine the optimum process combination. The research findings indicate that a 10% filler concentration yielded the highest stiffness, while a 20% filler concentration resulted in the largest strain value and demonstrated the best balance between strength and flexibility. A temperature of 170°C emerged as the most stable condition for most mechanical parameters, whereas a temperature of 190°C provided an increase in strength at higher filler compositions. From this study, it was ascertained that the optimal parameters are a 20% filler concentration and a temperature of 170°C (N1), yielding MOR, MOE, and strain values of 1473.53 MPa, 1186 MPa, and 2.86%, respectively. These findings affirm the critical importance of controlling the filler composition and processing parameters in producing biocomposites that are consistent and high-performing.

A Numerical Study on the Effectiveness of U-Shaped Steel Metallic Dampers Applied to Braced Building Structures under Dynamic Loading

Efrizal — 2026-05-25

The increasing demand for seismic-resilient structures has encouraged the development of advanced energy dissipation devices capable of reducing structural damage under strong ground motions. Among various passive control systems, metallic dampers have gained significant attention due to their stable hysteretic behavior, high energy dissipation capacity, and simplicity of installation. This study investigates the seismic performance of a building structure equipped with U-shaped steel metallic dampers installed within a chevron bracing system. The research is conducted through two complementary analytical stages. First, a detailed nonlinear finite element analysis is performed to evaluate the cyclic behavior of the U-shaped damper, accounting for both material and geometric nonlinearities. The resulting hysteresis curves are used to determine the elastic stiffness and energy dissipation capacity of the damper. In the second stage, the obtained mechanical properties are implemented into a dynamic numerical model of a multi-story building, where the damper is represented as spring element connecting the bracing system to the main structural frame. Linear time-history analyses are then conducted under earthquake ground motions to assess the dynamic response of the structure. The seismic performance of the damped structure is compared with that of an identical structure without metallic dampers in term of dynamic response. The results demonstrate that the proposed U-shaped metallic damper significantly enhances seismic performance by reducing structural demands and concentrating inelastic deformations within replaceable energy-dissipating components

Design and Testing of Twin-Disk Friction Torque Test Rig Using Quality Function Deployment and Function Analysis Methods Approach

Dedison Gasni — 2026-05-25

Fatigue failure is the most common failure in gears besides failure due to friction and wear on the surface of the gear. To determine the failure phenomenon that occurs in gears, testing can be done on the gear, but the testing will be expensive. So it is necessary to test on a laboratory scale to understand the failure mechanism of gears by designing and making a twin-disk friction torque test rig. The design process used an approach model developed by the National Aeronautics and Space Administration (NASA) to maximize user desires with the Quality Function Deployment (QFD) method approach and to be able to meet technical needs with the Function Analysis Methods (FAM) approach. The results of the design that has been done provide the design of a twin-disk friction torque test rig that has met user needs and, from the test results of the test rig's performance, has met the expected functional requirements as a test tool. From the results of tests that have been carried out on changes in load and slip ratio, the friction torque will increase with increasing load and slip ratio. While the friction coefficient will decrease with increasing load, and vice versa, with increasing slip ratio, the friction coefficient will increase. The data generated from the measurements are consistent, so the test rig can be used to measure friction torque.

Innovation of a Shallot Peeling Machine Based on Appropriate Local Resource Technology to Improve the Production Efficiency of Household Industries

Abdul Salam — 2026-05-25

Household industries engaged in shallot processing in Kapasa Raya, Makassar, face productivity constraints due to manual peeling methods that are time-consuming and labour-intensive. To address these challenges, an appropriate technology innovation was introduced through the design and implementation of a shallot peeling machine that is simple, ergonomic, and tailored to local needs. The research involved several stages, including field surveys, design using Fusion 360 software, fabrication, assembly, and performance testing. The test results indicated that the optimal parameter combination machine rotation speed of 112 rpm, a capacity of 2.5 kg, and peeling duration of 2 minutes with hot water soaking, was able to achieve an efficiency of up to 37.5 kg/hour. This innovation not only accelerates the peeling process and reduces operator fatigue but also maintains the visual quality of the shallots, thereby enhancing the competitiveness of MSME products. The adoption of this machine has proven to provide significant technical as well as socio-economic impacts for small-scale business operators.

Optimization of Starch Adhesive in Bagasse Charcoal Briquettes

Harmiansyah — 2026-05-25

The limitations of fossil energy are driving the development of the SDGs as the population and energy needs grow. Briquettes made from agricultural waste, especially bagasse, are a potential solution as an alternative energy source that is renewable, environmentally friendly, and can reduce dependence on fossil fuels while utilizing abundant sugar industry waste. This study aims to analyze the quality of bagasse waste briquettes with variations in the addition of starch flour as an adhesive with formulations (0%, 5%, 10%, and 15%). The manufacturing process includes a press method using a pressurized hydraulic machine to produce briquettes with SNI (01-6235-2000) quality standards. The quality parameters tested include density, moisture content, combustion rate, and drop test. The test results showed significant variation in characteristics between treatments. The SU3 treatment showed the highest density (0.7389 g/cm³) with the highest residual combustion ash (12.47%). The SU4 treatment showed the best physical characteristics with a drop test value of 99.11% and the lowest moisture content (20.98%). In addition, the SU4 treatment also has the second lowest combustion rate with a value of 0.084 gr/min, and the lowest combustion residue (1.7 gr). These findings indicate that the SU4 formulation produces briquettes with the best combination of physical characteristics and combustion efficiency.

Development of Control System for TU-2A CNC Machine

Ariawan Bayu Wicaksono — 2026-05-25

This study aims to design and develop an electronic control system for the TU-2A CNC machine to improve its performance, simplify the programming process, and facilitate machine maintenance and repair procedures. The method used is retrofitting the EMCO TU-2A CNC machine by replacing the old electronic components with more modern and affordable components, without compromising the machine's precision. Calibration is carried out to ensure the accuracy of the machine's movement, while machine testing is conducted by machining workpieces made of teflon (PTFE) and aluminum. The results of the study indicate that after the development and maintenance, the CNC TU-2A machine showed improvements in precision and ease of use. The machine's error remains within the tolerance limit, approximately 0.01 to 0.02 mm, indicating that the calibration was successful. The conclusion of this study is that the development of the new electronic control system has made the CNC TU-2A machine more efficient and easier to maintain, making it more suitable for use in vocational education.

Manufacture of a flying robot propeller made from plant-based composite material derived from snake plant (Sansevieria trifasciata) fibers.

Arsyad Mulya Rahman — 2026-05-25

The development of flying robot technology or Unmanned Aerial Vehicles (UAVs) requires innovations in materials that are lightweight, strong, and environmentally friendly. This study aims to design and manufacture flying robot propellers using composite materials with an epoxy resin matrix reinforced with natural fibers from snake plants (Sansevieria trifasciata). Sansevieria trifasciata fibers were chosen for their potential as an alternative material with good specific strength, abundant availability, and light weight. The propeller was manufactured using the hand lay-up method, followed by mechanical testing to determine the characteristics of the composite material, including tensile and impact tests. In addition, functional testing was conducted to measure the performance of the propeller in generating thrust. The results of the study show that Sansevieria trifasciata fiber composites have sufficient mechanical properties to be used as propeller materials for small-scale UAVs. The thrust performance produced is comparable to that of similar commercial propellers, indicating that natural fibers can replace conventional synthetic fiber-based materials and support more sustainable technological advances.

Analysis of the Effects of Laser Cutting Process Parameters on the Kerf Width of Plywood Using the Taguchi Method

ikhsan Muhammad Ikhsan — 2026-05-25

Laser cutting is widely used in the manufacturing industry due to its ability to produce high-precision cuts. However, the quality of the cutting results is strongly influenced by the process parameters applied. This study aims to analyze the effects of laser cutting process parameters on the kerf width of plywood material and to determine the optimal parameter conditions using the Taguchi method and analysis of variance (ANOVA). The investigated parameters include material thickness (1, 2, and 3 mm), cutting speed (30, 40, and 50 mm/s), and laser current (20, 30, and 40 A). The experimental design was developed using a Taguchi orthogonal array, while the quality characteristic employed was the smaller-is-better criterion. The analysis results indicate that material thickness is the most influential factor affecting kerf width, with a contribution of 94.99%. Cutting speed and laser current exhibit smaller effects and are not statistically significant. The optimal conditions for minimizing kerf width are obtained at a material thickness of 3 mm, a cutting speed of 50 mm/s, and a laser current of 20 A. The ANOVA results confirm the consistency of the Taguchi analysis, leading to the conclusion that controlling process parameters—particularly material thickness—plays a crucial role in improving the precision and quality of laser cutting results on plywood materials.

Stress and Stiffness Analysis of Geometric Design of Structure Universal Testing Machine 1 Ton Capacity With Ribbing Technology Using Finite Element Method

reski septiana — 2026-05-25

A machine structure is designed with a high stiffness concept [1]. Low stiffness leads to deformation of the machine structure, which can degrade the quality of the resulting product. High machine structural stiffness is used in machine tools, material testing machines, and other testing machines, such as universal testing machines. High machine structural stiffness is always accompanied by a large machine design volume, which requires the use of large amounts of material, resulting in high volume and weight and high production costs. To overcome this, ribbing technology is used [2-5]. Ribbing technology functions to prevent deformation in the machine structure while reducing the machine's volume. This study aims to apply and analyze the structural stiffness of a universal testing machine with various ribbing configurations using the finite element method [6-9]. The results show that the thicker the ribbing dimension, the smaller the resulting deflection, and the smaller the deflection, the greater the stiffness. The simulation results show that the highest deflection value was obtained for the 4 mm thick Box model using AISI 1010 material (1.55 mm), while the smallest was for the 16 mm thick X model using AISI 1045 material (1.26 mm). The lowest stiffness value was found for the 4 mm-thick Box model using AISI 1010 material (6472.49 N/mm), while the highest was found for the 16 mm-thick X model using AISI 1045 material (7936.51 N/mm).

Effectiveness of Roof Structures as Dynamic Vibration Dampers in Buildings under Dynamic Loading

Eka Satria — 2026-05-25

Buildings located in earthquake-prone regions are vulnerable to dynamic responses that may cause severe structural damage if not effectively controlled. One emerging approach for seismic response mitigation is the utilization of roof structures as dynamic damping systems. By appropriately tuning the mass, stiffness, and damping characteristics, roof structures can function as dynamic vibration absorbers through interaction with the main structural system. This study evaluates the effectiveness of roof structures acting as dynamic dampers in reducing the seismic responses of buildings. The research is conducted in two stages. The first stage involves a static analysis of U-shaped metallic dampers using the finite element method to determine stiffness and energy dissipation characteristics based on hysteresis curves obtained from cyclic loading. The second stage consists of a dynamic analysis in which the building structure and roof are modeled as a two-dimensional frame system, with metallic dampers installed between the building and the roof. Damper parameters are adopted from the static analysis results, while the roof mass is analytically determined to ensure its effectiveness as a dynamic damper. Dynamic analyses under earthquake excitation are performed to evaluate the reduction in structural displacement. The results indicate that roof-based damping systems can significantly reduce peak dynamic responses, particularly roof displacement and inter-story drift, demonstrating their potential to enhance the seismic performance of buildings in earthquake-prone regions