1,721,006 research outputs found
RE-RATING PRESSURE VESSEL SETELAH PENINGKATAN TEMPERATUR DAN INTERNAL PRESSURE SERTA AKIBATNYA TERHADAP FATIGUE DAN REMAINING LIFE
Full text linkAfter the issuance of the latest regulation by BPOM, namely BPOM Regulation Number 20of 2019 concerning Food Packaging, several industries have made changes to their productionprocesses. This made one of the well-known beverage companies make changes to the initial pressurevessel design. It is necessary to increase the internal pressure and temperature so that the productionprocess complies with these regulations. In this case, the pressure vessel has been re-rated after thechanges of the initial design. Research is needed to determine the strength and remaining life throughstress and fatigue analysis. The remaining life calculation results show that after re-rating, the pressurevessel has a remaining life value of 70 years. This value is 1 year lower than the remaining life beforere-rating, which is 71 years. The results of the stress analysis show that the highest stress is in thestiffener of head, which is 11.530,54 psi, this value is still below the allowable stress value, which is18.300 psi. The results of the fatigue analysis show that the value of the fatigue life cycle is infinite, sothat the pressure vessel can operate during its design lifetime, which is 20 years
ANALISIS KOMBINASI ELEKTRODA PADA PENGELASAN DISSIMILAR MATERIAL SA 516 GR70 DENGAN SA 240 TYPE 316L DENGAN BUTTERING LAYER PROSES PENGELASAN FCAW TERHADAP SIFAT MEKANIK DAN STRUKTUR MIKRO
Full text linkDissimilar welding is a technique used to joint two different metal materials. Inthis research using SA 516 GR70 material with SA 240 type 316L with FCAW weldingprocess. This research was carried out a welding process with a buttering layer using acombination of E309 electrodes with filler metal using E71T and E316L with a comparisonof a combination of E312 electrodes with filler metal using E71T and E316L. Thecombination variations were tested visually, tensile, bending, hardness, and metallography.In visual testing, no defect were found in the test specimens. In tensile testing the butteringlayer E309-E71T has the highest tensile strength of all other test specimens which is 639.16Mpa. In the bending test of all test specimens, only buttering layer E309-E316L passed thyeacceptance requirements. In the hardness test, the highest average in the weld metal isfound in buttering layer E312-E71T with an average value 302.35 kgf/mm2. In macrotesting the HAZ width of the E312 buttering electrode is wider than E309. In micro testingin each specimen there are ferrite, pearlite, delta-ferrite, and austenite structures
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Analisis Perbandingan Kombinasi Elektroda, Preheat, dan Interpass pada Pengelasan GMAW Dissimilar Baja Bisalloy 400 dan SM490YA Terhadap Kekerasan
Full text linkA construction company manufactured a side dump trailer that was used to transport coal. This side dump trailer, experienced a failure on the floor in the form of a crack in the welding joint. The material used in this welding joint is dissimillar material between Bissalloy 400 steel and SM490YA. This study aims to analyze the failure and repair it by performing a combination of electrodes, preheat, and interpass on the mechanical and metallographic properties of Bisalloy 400 and SM490YA steel materials. To determine the hardness value, testing was carried out. The hardness test results obtained the highest hardness value of 385 HVN. The hardness test showed that increasing the preheat and interpass temperatures decreased the hardness of the material. The use of a buffer layer between two dissimilar materials proved effective in reducing the risk of cracking and deformation. This study confirms the importance of selecting the right welding parameters to improve joint quality in dissimilar materials with significant differences in carbon equivalent
ANALISIS PENGARUH VARIASI LASER POWER DAN WOBBLE FREQUENCY PROSES LASER WELDING PADA MATERIAL SUS 304 TERHADAP STRUKTUR MIKRO DAN NILAI KEKERASAN
Full text linkWelding is a major process in fabrication industry of transportation. So, that required efficiency and good welding results. This study used laser welding process with 1 mm thickness austenistic SUS 304 material. Crucial parameters in laser welding are power and wobble frequency, because they can affect material’s mechanical properties. This research was conducted to determine the effect of varying power and wobble frequency values ??of SUS 304 material on the microstructure and hardness values. The power used was 33% and 38% varied with wobble frequencies 10 Hz and 12 Hz. The specimen testing are visual inspection, macro structure test, micro structure test, SEM, and hardness test. The results of macro structure test show that the greater power and wobble frequency values, the deeper penetration. Micro-test results on the material show that the formation of lathy ferrite occurs in areas with a high cooling rate, while skeletal ferrite is formed in areas with a low cooling rate. The highest hardness value in weld metal area is at variation 38% power and 12 Hz wobble frequency, which is 197.23 HV. SEM testing showed no micro size defects and finer grain structures. It shows that the greater the value of power and wobble frequency, the deformation occurs and the results of the welding are increasingly concave
ANALISIS FATIGUE LIFE PADA CHASSIS SIDE DUMP TRUCK 085 DENGAN METODE ELEMEN HINGGA
Full text linkSide dump trucks must be ensured to be in good condition and able to safely support the load. Usually, in the transportation process, repetitive stresses occur that can cause fatigue over a period of time, which affects the construction life. This journal objective is to analyze and evaluate the fatigue life value of the chassis frame to understand its effect on stress location, highest stress value, and construction life using Ansys workbench software. Modeling is carried out using Autodesk Inventor software and converted into Ansys for simulation so that the stress range value is obtained for each loading. Furthermore, manual fatigue life calculations were carried out with reference to AWS D1.1. The simulation results showed that the highest stress occurred within the area inside the support hanger. The highest stress range occurs in 95 tons loading which is 125.57 MPa, that has a life of 75.93 years. While, the lowest stress range occurs in 85 tons loading which is 112.35 MPa, that has a lifespan of 106.04 years. The result of this study show that the greater the load the smaller the construction life
ANALISIS PENGARUH HOLDING TIME ARTIFICIAL AGING DENGAN PENGELASAN GTAW PADA ALUMINIUM ALLOY 6061 TERHADAP SIFAT MEKANIK DAN METALLOGRAPHY TEST
Full text linkAluminum is one of the most widely used non-ferrous metals in the engineering field because it haslightweight, corrosion-resistant, and recyclable properties To meet the eligibility of bicycles for sale, bicycleframes must have a hardness value of 16-17 HRE (112-142 HVN). However, initially this material has ahardness value of 4-6 HRE, therefore it is necessary to do heat treatment after welding or it can also be calledPWHT. This research was conducted to find the effect of holding time artificial aging on tensile value,microstructure, and hardness. The tensile test results show that the highest average nikai is at the holding timeartificial aging 4 hours, which is 250.93 Mpa. The microstructure test results show an increase in the numberof Mg2Si phases and the denser the microstructure if it is at the right holding time.. In microstructure testing,specimens with holding time artificial aging 4 hours have the most Mg2Si structure so that it is homogeneousso that it has the highest average hardness as well. The hardness test results show that the highest value is inthe base metal with a holding time of artificial aging 3 hours, which is 133.80 HVN and the lowest in thespecimen with a holding time of 5 hours, which is 116.2 HVN. Especially in the weld metal area, the highesthardness is in the specimen with a holding time of 4 hours, which is 95.3 HVN and the lowest hardness valueis in the specimen with a holding time of artificial aging 5 hours, which is 82.2 HVN. So it can be concludedthat with the influence of the right holding time can increase the value of hardness and improve the finalstructure of the material
ANALISIS METODE TEMPER BEAD WELDING MENGGUNAKAN HALF BEAD TECHNIQUE DAN CONTROLLED DEPOSIT WELD PADA MATERIAL SA 387 GRADE 11 SEBAGAI PENGGANTI PWHT
Full text linkThe fabrication industry is an effort to produce raw goods into finished goods, PT. X is oneof the fabrication companies engaged in steel fabrication which focuses on working on steel structures,working on vessels and boilers. Through the production process of large quantities of boiler work afterthe welding process there are things that must be considered, one of which is post weld heat treatment(PWHT). But in fact PWHT has many shortcomings due to several factors such as relatively expensivecosts and long time consuming. Therefore, there is a method that can be used as an alternative to thepost weld heat treatment (PWHT) process, namely the Temper Bead Welding technique, which is ableto provide efficiency and effectiveness in its implementation. Within the framework of this research,two methods, Half Bead Technique and Controlled Deposit Weld, were analyzed in comparison withthe PWHT method. The welding process applied is Shielded Metal Arc Welding (SMAW), with theimplementation of a series of tests including tensile testing, bending test, hardness test, andmicrostructure analysis. The overall mechanical test results meet the predetermined acceptancecriteria for SA 387 Grade 11 materials. From the hardness test results, the results obtained show thatthe Half Bead Technique and Controlled Deposit Weld techniques each produce the highest averagevalue in the Heat Affecte region
ANALISIS WELDING SEQUENCE DENGAN PENAMBAHAN TRANSIENT THERMAL TENSION PADA DUCTING TERHADAP DEFORMASI DAN TEGANGAN SISA
Full text linkIn fabrication process of a construction there is often experiences obstacles within the implementation. Deformation is an obstacle that often occurs and can holding up the further fabrication process. Deformation causes problems in the form of misaligned connections between parts, which can cause excessive stress concentrations. Like the process of ducting which had deformation during the assembly process. Ducting deformation occurs in the base metal part after the welding process is carried out between one part and another. This problem happen as a result of excessive heat input on some sides, so that the heat is distributed unevenly across the base metal. The purpose of this final project research to analyze of welding sequence and the addition of transient thermal tension on deformation and residual stress in ducting using the finite element method. After the analysis was done, the results were obtained in the form of a quite significant difference in the deformation of welding sequences, where welding sequence 2 was 2.1169 mm. Then the residual stress that occurs of welding sequences is 192.27 MPa. From welding sequences are given additional heat that is line heating and the results obtained can reduce deformation significantly. However, the addition of heat can increase the high residual stress on welding sequence with transient thermal tension 200 °C distance 1000 mm the value up to 806.45 MPa. From the results , it is concluded that the greater the deformation value that given, the smaller the residual stress value will be. Otherwise , the smaller the deformation value, the greater the residual stress value
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