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Contact Name
Rahmat Azis Nabawi
Contact Email
raazna@ft.unp.ac.id
Phone
+6281277328670
Journal Mail Official
Syahril@ft.unp.ac.id
Editorial Address
Jl. Prof. Dr. Hamka Kampus UNP Air Tawar
Location
Kota padang,
Sumatera barat
INDONESIA
Teknomekanik
ISSN : 26219980     EISSN : 26218720     DOI : 10.24036/tm.
Core Subject : Engineering,
Teknomekanik is an international journal that publishes peer-reviewed research in engineering fields (miscellaneous) to the world community. Paper written collaboratively by researchers from various countries is encouraged. It aims to promote academic exchange and increase collaboration among scientists, engineers and researchers to support sustainable development goals.
Articles 111 Documents
Monitoring mission for multi-drones using decentralized chaos-bidding consensus with backstepping control via lyapunov barrier functions Romdlony, Muhammad Zakiyullah; Khayr, Rashad Abul; Nazaruddin, Yul Yunazwin; Tamba, Tua Agustinus; Kamal, Md. Abdus Samad
Teknomekanik Vol. 8 No. 2 (2025): Regular Issue
Publisher : Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/teknomekanik.v8i2.36072

Abstract

The mobility and flexibility of a quadrotor make it a popular choice for monitoring missions in remote areas. However, remote environments introduce constraints due to limited charging and communication stations that must be considered, alongside the possibility of collision with the environment. To ensure the quadrotor task was completed, a decentralized chaos-bidding consensus for decentralized task allocation was proposed, accompanied by control, Lyapunov, and barrier functions. These functions were simplified using the backstepping method to ensure the quadrotor's safety during task execution. The proposed method was evaluated through numerical simulation in multiple situations. The results indicate a minimum of 3% reduction in task completion time compared to other methods. When the battery constraint was applied, the proposed method successfully directed the drone to return to base before battery depletion and reassigned the task to other available quadrotors, thereby reducing the overall completion time for the entire system. Furthermore, this framework demonstrates the potential to support long-duration missions where continuous operation is required without relying heavily on ground control. The decentralized nature of the system also increases scalability, allowing multiple quadrotors to cooperate efficiently under dynamic environmental conditions. These advantages highlight the relevance of the proposed control strategy for practical field deployment, particularly in inaccessible locations.
Multiclass gas pipeline leak detection using multi-domain signals and genetic algorithm-optimized classification models Suprihatiningsih, Wiwit; Romahadi, Dedik; Pranoto, Hadi; Youlia, Rikko Putra; Anggara, Fajar; Rahmatullah, Rizky
Teknomekanik Vol. 9 No. 1 (2026): Regular Issue
Publisher : Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/teknomekanik.v9i1.38372

Abstract

Pipeline networks are critical infrastructure for oil and gas transport because the occurrence of leaks can rapidly escalate into safety, economic, and environmental crises. Operators are practically required to identify the presence and type of leaks; however, applying multiclass recognition is challenging when labeled data and computing power are limited. Therefore, this study proposes a three-stage pipeline which consists of: (1) adopting the GPLA-12 dataset of acoustic or vibration signals spanning 12 leak types; (2) extracting multi-domain features by combining time-domain descriptors with Power Spectral Density (PSD)-based spectral features; and (3) applying a genetic algorithm (GA) as a wrapper for feature selection to enhance discriminability and reduce dimensionality, which was followed by benchmarking seven conventional classifiers and GA-based refinement of the top model with a focus on the feature subset and hyperparameters. A maximum accuracy of 96.35% was achieved on the GPLA-12 dataset with low computation time and a simple model architecture. The proposed pipeline also attained similar or better accuracy at substantially lower complexity and data requirements compared with prior deep CNN approaches. These results support timely multiclass decision-making in resource-constrained industrial settings. A key observation was that the focus was on supervised leak-type classification from acoustic or vibration signals, while localization, severity estimation, and multi-sensor fusion were beyond the scope of this study.
Trends in anti-UV films or composites: A bibliometric study Rahmadiawan, Dieter; Santos, Thiago F.; Aslfattahi, Navid; Shi, Shih-Chen; Indrawan, Eko; Ramadhan, Athaya; Abadi, Zainal
Teknomekanik Vol. 8 No. 2 (2025): Regular Issue
Publisher : Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/teknomekanik.v8i2.44072

Abstract

Anti-UV films and composites play a critical role in protecting materials from ultraviolet-induced degradation, which can weaken polymers, reduce product lifespan, and compromise performance in sectors such as food packaging, outdoor coatings, and biomedical devices. The growing emphasis on sustainability and the need for environmentally friendly protective materials have further accelerated research on UV-shielding technologies that incorporate biopolymers, multifunctional additives, and renewable resources. This study presents a comprehensive bibliometric analysis of global research on anti-UV films and composites over the period 2014–2024. Data were retrieved from the Scopus database and analyzed using Bibliometrix (R package) and VOSviewer were employed to analyze publication patterns, map keyword networks, and visualize thematic evolution, as these tools enable robust quantitative and structural mapping of large bibliographic datasets. Three dominant thematic clusters were identified: (i) nanoparticle-based UV shielding using inorganic fillers such as ZnO and TiO₂, (ii) multifunctional films integrating UV protection with antibacterial and antioxidant properties, and (iii) biopolymer-based matrices emphasizing mechanical durability and environmental sustainability. These clusters highlight the convergence of performance, sustainability, and multifunctionality as key drivers shaping current research directions. Despite significant progress, the analysis reveals limited attention to scalability, industrial compatibility, and long-term performance evaluation. The findings underscore the need for future research to incorporate pilot-scale processing, life-cycle assessments, and interdisciplinary collaboration to bridge the gap between laboratory formulations and commercial implementation. Overall, this bibliometric study provides a consolidated understanding of the evolution and research landscape of anti-UV films and composites.
Comparative analysis of bio-inspired and topology-optimized lattices under compressive loading Arifin, Ahmad Anas; Batan, I Made Londen; Bici, Michele; Wahjudi, Arif; Pramono, Agus Sigit
Teknomekanik Vol. 9 No. 1 (2026): Regular Issue
Publisher : Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/teknomekanik.v9i1.45472

Abstract

Lattice structure design is still dominated by strut-based forms and surface-based shapes, such as triply periodic minimal surfaces (TPMS), which both exhibit overlapping limitations. Strut lattices often show strong anisotropy because their response depends heavily on cell orientation, while TPMS lattices are difficult to adjust when bounded by geometric constraints. These conditions eventually led to stagnation in the development of lattice morphology. Hybrid and topology-optimization methods have appeared as possible alternatives, but many of them still produce modified versions of classical patterns. This study examined two lattice geometries: the Pyramorph, inspired by the shape of a pyramid, and the Topomorph, generated through a topology optimization framework. Both structures were designed using a CAD unit cell patterning technique and manufactured using the FDM method, with relative densities ranging from 0.40 to 0.44. Their mechanical behaviour was examined through FEA simulation and uniaxial compression testing. The parameter variations included cell orientations of 0°, 15°, 30°, and 45°, and cell sizes of 8 mm and 12 mm within a 24 mm specimen. The Topomorph showed superior strength, reaching 15–20 MPa, while the Pyramorph reached only 7–8 MPa. The highest value, about 20.5 MPa, was obtained from the Topomorph at 0° and with an 8 mm cell size. Failure modes indicated buckling and delamination in the Pyramorph, while the Topomorph tended to collapse progressively. These findings indicate that topology optimization combined with CAD-based patterning could significantly improve lattice performance.
Loading-dependent mechanical performance of alkali-treated areca nut husk fiber reinforced polyester composites modified with Uncaria gambir extract Nabawi, Rahmat Azis; Syahril, Syahril; Abral, Hairul
Teknomekanik Vol. 8 No. 2 (2025): Regular Issue
Publisher : Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/teknomekanik.v8i2.52472

Abstract

Natural fiber-reinforced polymer composites often experience mechanical performance limitations due to weak interfacial bonds between hydrophilic fibers and hydrophobic matrices. This study experimentally examined the effect of alkali treatment and modification using Uncaria gambir extract (UGE) on the mechanical properties and interface morphology of polyester composites reinforced with areca nut husk fiber (ANHF). Four composite configurations were prepared with a constant fiber weight fraction of 40 wt.% after alkali treatment using 6% NaOH for 24 hours, while the remaining 2 wt.% UGE was selectively applied as a fiber surface treatment, matrix additive, or a combination of both. Tensile and flexural properties were evaluated in accordance with ASTM standards, while interface morphology was examined using scanning electron microscopy (SEM). The results showed that alkali-treated composites without UGE addition had the highest tensile strength, which was attributed to increased fiber surface roughness and mechanical interlocking mechanisms. Conversely, fiber surface modification using UGE significantly increased flexural strength, indicating better stress distribution under flexural loading due to increased interface continuity. However, the addition of UGE to the matrix caused a decrease in tensile strength, which was thought to be related to a reduction in matrix stiffness. SEM observations confirm the presence of distinct interface morphology differences according to the treatment applied. These findings indicate that UGE serves primarily as a bio-based interfacial modifier, enhancing flexural performance, while its effectiveness is strongly governed by the mechanical loading mode.
Grid convergence analysis of an H-Darrieus wind turbine for multiple blade configurations Nasution, Sanjaya Baroar Sakti; Nasution, Dian Morfi; Wijaya, Elang Pramudya; Ompusunggu, Oki Suprada
Teknomekanik Vol. 9 No. 1 (2026): Regular Issue
Publisher : Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/teknomekanik.v9i1.45272

Abstract

Mesh size and number significantly affected the accuracy of CFD simulations in wind turbine analysis. However, most studies focused solely on turbine performance, such as the blade torque or power coefficients. Therefore, this study adopted a broader perspective by analyzing the influence of mesh resolution on both aerodynamic performance and key fluid-dynamic parameters, including vorticity and pressure coefficients, for an H-type Darrieus vertical-axis wind turbine. Two-dimensional CFD simulations were performed using ANSYS Fluent with the k–ω SST turbulence model. Five mesh levels were evaluated across different blade configurations, and the Grid Convergence Index (GCI) was used to quantify discretization errors. The results indicate that increasing mesh resolution yields more stable torque predictions and improved resolution of near-wall flow features, with consistent grid-convergence behaviour observed across all blade configurations. GCI analysis shows that discretization errors consistently decrease as the mesh becomes finer. It also shows that a grid size of about 1.6 x 105 cells is sufficient to keep errors below 5%. These findings show that including flow-field details in mesh sensitivity analysis gives a better way to check the accuracy of CFD simulations for Darrieus wind turbines.
Uniaxial and biaxial hot pressing of PVDF films: A pathway toward high-performance piezoelectric sensors and energy harvesters Suprapto, Suprapto; jubaidah, Jubaidah; Triono, Selamat; Gunawan, Harianto; Lisyanto, Lisyanto; Nugraha, Aditya Sukma; Aldori, Yopan rahmad
Teknomekanik Vol. 9 No. 1 (2026): Regular Issue
Publisher : Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/teknomekanik.v9i1.44972

Abstract

The piezoelectric efficiency of Poly (vinylidene fluoride) (PVDF) membranes becomes restricted by the challenge of generating and stabilizing electroactive β-phase during processing. Stretching requires control of deformation parameter, while solvent-based methods bring environmental and occupational health risks. This research suggests hot-pressing as an alternative method for enhancing β-phase fraction, utilizing multidirectional stress without solvent or chemical exposure. This study systematically compares uniaxial hot-pressing (Uniaxial HP) and biaxial hot-pressing (Biaxial HP) setups to determine which stress distribution is more effective at promoting changes and improving piezoelectric properties in PVDF membranes. The main objective of this research is to systematically evaluate and compare the impacts of uniaxial and biaxial hot-pressing on the crystalline phase transformation and electromechanical performance, including the piezoelectric coefficient (d33) and output voltage response of PVDF membranes. PVDF pellets were hot-pressed at 220o C under a pressure of 60 MPa for 15 minutes followed by rapid quenching in ice water. X-Ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) confirmed phase composition, correlated with performance via the piezoelectric coefficient (d33), and assessed piezoelectric activity. Experimental results show that biaxial loading provides a higher b-phase fraction (50.47%) compared to untreated membranes (47.80%) and UHP samples (49.30%). The crystallinity and the piezoelectric coefficient also increased to 49% and 18.8 pC/N, respectively. Biaxial stress pattern during hot-pressing induces favourable thermodynamic and kinetic conditions for b-phase expansion. Beyond phase-related results, the approach delivers competitive piezoelectric effectiveness while maintaining simplicity and reducing solvent-dependent processing steps.
Effects of process parameters on the evaporative pattern casting of scrap aluminum–RHA composites Siswanto, Rudi; Ghofur, Abdul; Subagyo, Rachmat; Tamjidillah, Mastiadi; Mahmud, Mahmud; Ma’ruf, Ma’ruf; Nordiman, Adi
Teknomekanik Vol. 9 No. 1 (2026): Regular Issue
Publisher : Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/teknomekanik.v9i1.46072

Abstract

This study investigates the fabrication and characterization of aluminium matrix composites reinforced with rice husk ash (RHA), using scrap aluminium as the base material and evaporative pattern casting as the manufacturing method. The work evaluates the effects of three key independent variables: pouring temperature, aluminium (Al)-RHA composition ratios, and styrofoam pattern thickness on the resulting composite properties. The dependent variables examined include surface roughness, Brinell hardness, and dimensional shrinkage-expansion. Experimental results show that increasing the pouring temperature and adjusting the composition ratio significantly influence the mechanical and physical properties of the composites. The highest hardness (45.6 HB) and fluidity (252.65 mm) were achieved at a 60:40 composition ratio and a pouring temperature of 750 °C, albeit at the cost of increased porosity. Additionally, the styrofoam pattern thickness was found to affect the dimensional stability and surface roughness of the composites, with thicker patterns resulting in higher surface roughness. This study highlights the potential of utilizing rice husk ash as a reinforcing material in aluminium matrix composites, offering a sustainable approach to improving material properties. The findings suggest that an optimal balance of composition ratio, pouring temperature, and pattern thickness is crucial to achieving desirable mechanical and physical characteristics, with implications for advanced manufacturing processes in the materials industry.
Optimization of bio-based cellulose-phosphate hydrogel production from rice husk waste using the Taguchi method Aprilyanti, Selvia; Pratiwi, Irnanda; Andalia, Winny; Aprianti, Tine; Faritzie, Hariman Al
Teknomekanik Vol. 9 No. 1 (2026): Regular Issue
Publisher : Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/teknomekanik.v9i1.47172

Abstract

This work reports the development and statistical optimization of a fully Bio-based absorbent hydrogel synthesized from rice husk–derived cellulose via phosphoric acid crosslinking. Cellulose was extracted through sequential chemical treatments and subsequently converted into a phosphate-crosslinked hydrogel using a controlled synthesis process. A Taguchi L16 (4⁵) orthogonal array was employed to optimize four key synthesis parameters: cellulose content, reaction time, heating temperature, and phosphoric acid volume. Hydrogel structure and morphology were characterized using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). FTIR results confirmed the formation of phosphate ester linkages, indicating successful crosslinking, while SEM observations revealed a porous and interconnected network structure favorable for water absorption. The optimized hydrogel formulation achieved a maximum swelling ratio of 91.25 g/g, demonstrating effective absorbent performance despite the absence of synthetic monomers or grafting agents. These findings indicate that rice husk waste can be efficiently valorized into an environmentally benign absorbent material through a simple and statistically guided synthesis route, supporting sustainable hydrogel development and agricultural waste utilization.
Spatial modelling of shallow groundwater quality in coastal areas with Kriging interpolation Arbi, Yaumal; Syah, Nurhasan; Umar, Iswandi; Dewata, Indang; Gusman, Mulya; Sandra, Nevy
Teknomekanik Vol. 9 No. 1 (2026): Regular Issue
Publisher : Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/teknomekanik.v9i1.47272

Abstract

This study maps shallow coastal groundwater quality in Padang, Indonesia, using four operational parameters: potential of hydrogen (pH), electrical conductivity (EC), total dissolved solids (TDS), and salinity. We characterize spatial dependence using empirical variograms, evaluate directional anisotropy, and generate prediction surfaces with Ordinary Kriging. The variogram analysis indicates stronger spatial continuity along the coastline for EC and TDS, while salinity shows shorter continuity with a distinct directional structure, reflecting localized freshwater-seawater mixing processes. Groundwater pH remains neutral to slightly alkaline and exhibits lower spatial variability than EC, TDS, and salinity. Leave-one-out cross-validation supports the reliability of the kriging estimates at the study scale, indicating low prediction error and strong agreement between observed and predicted values. The resulting thematic maps enable a three-level quality zoning that differentiates a lower-risk northern segment, a transitional central belt, and a higher-risk southern segment consistent with seawater intrusion influence. These outputs provide a practical basis for prioritizing monitoring locations, protecting vulnerable wells, and strengthening evidence-based coastal groundwater management aligned with SDG 6 Clean Water and Sanitation and SDG 11 Sustainable Cities and Communities.

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