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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
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.
Articles 40 Documents
Wind Turbine Vertical Axis H Rotor Type with 1 KW Capacity at Suwuk Beach, Kebumen Gustiantono, Achmad; Dwi Prija Tjahjana, Dominicus Danardono; Hadi, Syamsul
Mekanika: Majalah Ilmiah Mekanika Vol 16, No 1 (2017): MEKANIKA: Majalah Ilmiah Mekanika
Publisher : Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/mekanika.v16i1.35053

Abstract

Tulisan ini membahas tentang analisa potensi energi angin di pantai Suwuk Kebumen dan perancangan turbin angin tipe H-Rotor yang sesuai dengan karakteristik angin di pantai tersebut. Analisa potensi energi angin menggunakan metode distribusi Weibull berdasarkan data kecepatan angin di lokasi pengukuran selama 2 tahun. Analisa distribusi Weibull menunjukkan karakteristik kecepatan angin di lokasi pengukuran yang akan dijadikan dasar dalam perancangan turbin angin H-Rotor. Perancangan turbin angin H-Rotor terdiri dari komponen-komponen seperti sudu, strut, dudukan strut, poros, tiang, dan generator. Diperoleh rancangan turbin angin H-Rotor dengan diameter x tinggi sebesar 2,7 x 2,7 meter menggunakan airfoil tipe NACA 0018 dengan kapasitas daya keluaran sebesar 1 kW.
ANALISIS PENGARUH INFILL OVERLAP TERHADAP KARAKTERISTIK PRODUK HASIL 3D PRINTING DENGAN MENGGUNAKAN MATERIAL POLY LACTIC ACID (PLA) Ardion, Fajri Sri; Sukanto, Heru; Triyono, Joko
Mekanika: Majalah Ilmiah Mekanika Vol 18, No 2 (2019): MEKANIKA: Majalah Ilmiah Mekanika
Publisher : Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/mekanika.v18i2.35408

Abstract

Rapid prototyping or commonly known as additive manufacturing uses metal and non-metal semi-liquid materials which are compacted layer by layer. Fused deposition modeling (FDM) is one of the methods in the additive manufacturing process that uses thermoplastic filaments (PLA and ABS). Poly Lactic Acid (PLA) or poly lactic acid is an organic plastic or bioplastic made from renewable biomass sources such as corn starch, pea starch and vegetable oils. Important factors affecting the quality of 3D Printing results are nozzle diameter, nozzle temperature, bed temperature, infill patern, infill percentage, print speed, layer thickness and infill overlap. Infill overlap is the percentage of overlapping processes of the filament during the printing process. This research was conducted to determine the effect of infill overlapon the physical and mechanical properties of 3d printing products. The infill overlapvariations used are 0%, 25%, 50%, and 75% of the nozzle diameter. 50% variation shows better quality when compared to other variations for density test, tensile test, and bending test.
Fiber Weight Fraction Effect to Acoustic Properties of RHDPE Cantula Composite Hendrowarsito, Muhammad Taufik Burhany; Raharjo, Wijang Wisnu; Himawanto, Dwi Aries
Mekanika: Majalah Ilmiah Mekanika Vol 16, No 2 (2017): MEKANIKA: Majalah Ilmiah Mekanika
Publisher : Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/mekanika.v16i2.35058

Abstract

In this study, composites made from recycled HDPE and Cantula fiber have been done and the absorption coefficient have been measured. Composites rHDPE-Cantula were made using hot press for approximately 60 minutes with 170oC temperature while pressure exerted by 50 bar. In this study the weight ratio of Cantula fiber was varied 40%, 50%, 60%, and 70%. Impedance Tube Method was used to measure the sound absorption coefficient in accordance with ASTM E 1050. An increase weight ratio wasn?t influence the sound absorption coefficient significantly, but the optimum sound absorption coefficient shifted to the higher frequencies from 80-200 Hz. An increase weight ratio showed better sound absorption coefficient from 500-1600 Hz, but the result from 60% weight ratio showed low sound absorption coefficient that may caused by it high density leading to the reduction of porosity. This result was supported by density measurement in accordance with ASTM D 792, which the result showed that the sound absorption coefficient increase with decreasing of the density.
Simulasi efisiensi motor listrik axial bldc dengan bahan soft magnetik variasi kompaksi dan perlakuan panas menggunakan perangkat lunak ansys maxwell Herwangga, Rino; Nizam, Muh; Anwar, Miftahul
Mekanika: Majalah Ilmiah Mekanika Vol 17, No 2 (2018): MEKANIKA: Majalah Ilmiah Mekanika
Publisher : Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/mekanika.v17i2.35128

Abstract

The research was conducted to determine the efficiency of electric motors with soft magnetic composite and laminate by used software Ansys Maxwell. Soft magnetic composite material which was given 4, 5, and 6 tons of compaction pressure from previous research performed to fill the input data on electric motor efficiency simulation. The used datas were hysterisis curve which are resulted of VSM (Vibrating Sample Magnetometer) testing. Ansys Maxwell Rmxprt was used to simulate efficiency of electric motor. The results of Ansys Maxwell Rmxprt simulation were a relation curve between the efficiency? and the rotation of the electric motor. The results simulation of efficiency electric motor using soft magnetic composite core furthermore compared to the efficiency value of electric motor using laminate core. The results showed that the efficiency value of electric motor with soft magnetic composite with compacting pressure 4, 5 and 6 tons was 89,94 %, 89,97 %, and 90,62 % respectively. Efficiency value of electric motor with core laminate material was 91,22 %. The simulation showed that the value of a compaction pressure given on soft magnetic composite material affect on the efficiency of electrical motor. As a conclusion of this research that the efficiency value of electric motor trend increase with the value of compacting pressure on the material.?
PENGARUH TEMPERATUR KALSINASI TERHADAP SIFAT MEKANIK MATERIAL SCAFFOLD HIDROKSIAPATIT DARI TULANG KAMBING Eka Prawira, Setiawan; Triyono, Joko; Triyono, Teguh
Mekanika: Majalah Ilmiah Mekanika Vol 18, No 1 (2019): MEKANIKA: Majalah Ilmiah Mekanika
Publisher : Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/mekanika.v18i1.35042

Abstract

In this study, a preliminary study on the preparation of hydroxyapatite (HAp) as bone filler was made from sheep femur bone by calcination method. The femur of the sheep is cut into a form of scaffold with dimensions of 5 mm x 5 mm x 5 mm. The calcination process is performed at four variations of temperature (700oC, 900oC, 1100oC, 1300oC). Characterization of scaffold material done before and after calcination process, it intended to find out the influence and relationship between calcination of temperature on the mechanical properties of SHA material. The results of hardness testing show that the higher calcination temperature then the SHA material hardness value also increased. The optimum hardness value occurs at 1100oC calcination temperature of 38.23?0.985VHN. Meanwhile, high calcination temperature will also decrease the compressive strength of SHA material. The value of the optimum compressive strength is achieved at 1100oC calcination temperature of 2.23?0.249 MPa. The morphology of SHA scaffold was analyzed by Scanning Electronic Microscopy (SEM). The observation of SEM shows the occurrence of porous interconnections in all temperature variations. SEM analysis results show that porous interconnect is formed at all temperature variations with diameter size ? 100-500?m. Very high calcination temperature will give the impact of HAp wall is getting thinner and the porous diameter is getting bigger. Porous interconnection damage is also seen at 1300?C which causes the mechanical properties of SHA to decrease.
Pengaruh Debit Air Pendingin pada Proses Flame Heating terhadap Sifat Fisis dan Mekanik Aluminium 7075 Wicaksana, Ghailan; Triyono, Teguh; Muhayat, Nurul
Mekanika: Majalah Ilmiah Mekanika Vol 17, No 1 (2018): MEKANIKA: Majalah Ilmiah Mekanika
Publisher : Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/mekanika.v17i1.35047

Abstract

Aluminum alloy 7075 is a combination that are consists of 5,5% Zn, 2,5% Mn, 1,5% Cu, 0,3% Cr and 0,2% Mn. Heat treatment phase is using flame heating method. There are 3 steps of dissolution in flame heating process. The first is heat treatment solution in the temperature between 450-500?C. The second is quenching phase using flow speed variation 1000; 1200 and 1400 cc/minute and the third phase is using aging which to hold the room temperature until reaching 120?C. Specimen test phase using vickers hardness test, micro structure and impact test. Flame heating treatment process in 1000 cc/minute quenching cause specimen become harder, using hardness test 93,43 VHN is achieved. With additional aging treatment, the hardness increase to 152,63 VHN and almost close 153,80 VHN raw material. The biggest Impact test value is gained from the result of flame heating without aging with cooling flow variation of 1000 cc/minute is 0,630 J/mm?.
Welding Current and Shielding Gas Flow Rate Effect to The Intermetalic Layer Formation of Tungsten Inert Gas (Tig) on Dissimilar Metals Weld Joints Between Galvanized Steel and Aluminium Aa 5052 By Using Al-Si 4043 Filler Saputro, Gilang Sigit; ., Triyono; Muhayat, Nurul
Mekanika: Majalah Ilmiah Mekanika Vol 16, No 1 (2017): MEKANIKA: Majalah Ilmiah Mekanika
Publisher : Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/mekanika.v16i1.35052

Abstract

Tungsten Inert Gas welding of galvanized steel-aluminium useful for weight reduction, improve perform and reduce cost production. The effect of welding parameters, welding current and shielding gas flow rate on the intermetallic formation and hardness of dissimilar metals weld joint between galvanized steel and aluminium by using AA 5052 filler was determined. In this research, welding speed was consistent kept. The welding parameters were obtained by using welding currents of 70, 80 and 90 A, shielding gas flow rate of 10, 12 and 14 litre/min. The intermetallic layer thickness increased by welding currents of 70 A to 80 A, but then it dropped on 90 A. The higher of a shielding gas flow rate, the lower the thickness of the intermetallic layer. The higher of a welding current, the lower the hardness of weld. The higher of a shielding gas flow rate, the greater the hardness of weld. As a result,the maximum hardness by current variation of 70 A and a shielding gas flow rate of 14 Litre/min was 100.9 HVN.
PENGARUH VARIASI CAMPURAN OKSI-ASETILEN PADA PROSES FLAME HEATING TERHADAP SIFAT FISIS DAN MEKANIK ALUMINIUM SERI 7075 Purnadityanto, Purnadityanto; Triyono, Teguh; Muhayat, Nurul
Mekanika: Majalah Ilmiah Mekanika Vol 18, No 2 (2019): MEKANIKA: Majalah Ilmiah Mekanika
Publisher : Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/mekanika.v18i2.35406

Abstract

The optimum properties of aluminum can be achieved by the addition of alloy and heat treatment. An experimental study was conducted to investigate the effect of the oxy-acetylene mixture on the flame heating process on the physical and mechanical properties of aluminum 7075. Aluminum was heated to 480? C using an oxy-acetylene flame and then cooled rapidly. Then the results were compared with the specimen with flame heating + aging treatment. Variations of oxygen and acetylene mixtures were 0.75, 0.875 and 1 liter/min. The distance of the torch to the specimen's surface is 3 cm and the water flow rate is 1400 cc/min. The aging process is carried out with a temperature of 120?C for 3 hours + 165 for 1 hour. The results showed that the highest hardness value in flame heating treatment was 143,10 HVN with acetylene variation 0,875 liter/minute. The result of the impact test does not change much from the initial material toughness value, due to the average flame heating time that is not too long.
Natural Convection Numeric Simulation on Metal Freezing Using Differential Method Suprianto, Heri; Budiana, Eko Prasetyo; Widodo, Purwadi Joko
Mekanika: Majalah Ilmiah Mekanika Vol 16, No 2 (2017): MEKANIKA: Majalah Ilmiah Mekanika
Publisher : Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/mekanika.v16i2.35057

Abstract

The research of modeling of natural convection in metal solidification process with finite different method was conducted to determine temperature distribution and fluid flow profil with variations value Rayleigh number. The research conducted by solving governing equation of natural convection with finite difference approximation. Governing equation of natural convection consist of continuity equation, momentum equations, and energy equation. The ADI (Alternating Directional Implicit) method was used to discriteze for governing equation of natural convection. Finite difference method was written in Fortran language whereas the temperature distribution and fluid flow profile were visualized with Matlab software. The results of this research was validated by comparing the results obtained with Rajiv Sampath research. Comparison of the results of research showed good agreement. The result showed that solidification process occurs faster at Ra 10^4 compared?with 10^5 and?10^6
DIAGNOSA KERUSAKAN BANTALAN BOLA MENGGUNAKAN METODE SUPPORT VECTOR MACHINE Fathurrohman, Muhammad; Lambang G. H, R. Lulus; Susilo, Didik Djoko
Mekanika: Majalah Ilmiah Mekanika Vol 18, No 1 (2019): MEKANIKA: Majalah Ilmiah Mekanika
Publisher : Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/mekanika.v18i1.35041

Abstract

Bearings are the critical part of any rotating machine. The catastrophic failure of the bearing can lead to fatal and harmful to the operation of the machine. Therefore, predictive maintenance based on condition monitoring of bearing is very important. The objective of this research is to apply Support Vector Machine (SVM) method for fault diagnosis of the ball bearing. The research was carried out at the bearing test rig. Four types of ball bearing condition, such as normal, inner race defect, ball defect, and outer race defect were measured of the vibration signals using data acquisition with a sampling frequency of 20 kHz at the constant speed of 1400 RPM. Various features were extracted from vibration signals in time domain, such as RMS, variance, standard deviation, crest factor, shape factor, skewness, kurtosis, log energy entropy and sure entropy. PCA transformation was employed to reduce the dimension of feature extracted data. SVM classification problems were solved using MATLAB 2016a. The results showed that the application of RBF kernel function with the C parameter =1 was the best configuration. The training model accuracy was 98.93% and the testing accuracy of SVM was 97.5%. Finally, the research results show that the SVM classification method can be used to diagnose the fault condition of the ball bearing..

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