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This paper discusses the effect of element-length-to-thickness (ELT) ratio on midship structure analysis. Although it is widely known that every design must consider the best possible outcome of the design, indeed the simulation cannot produce the optimal analysis due to a variety of factors. During the study of the midship section configuration, the ELT ratio is one of the determining factors in the simulation. Since different ELT ratios would eventually produce different results, a calibration using the finite element method based on pioneer benchmarking studies is needed. The author designed a midship section using SolidWorks and ran the finite element analysis. The applied material is a titanium alloy, and the design’s boundary conditions are described as static loads, dynamic loads, and ELT ratios (in the range of 5-11). The midship design was tested with various ELT ratios, and the results, i.e., displacement, stress (von-Mises), and strain, were summarized. In terms of convergence tendency, midship displayed a displacement of 26.94 mm for the ELT ratio 10, with a strain of 5.579 × 10-4 and stress of 111.2 MPa. The displacement ratio was 0.97, the strain ratio was 0.917, and the stress ratio was 0.778 according to the simulation result. Different results can be presented by using different ELT ratios to assess the convergence tendency of the applied ELT ratios in finite element simulation. In contrast to the pioneer study, the ELT ratio converges on a scale of 10 with an average disparity of 11.16%.

The braking system is a vital component for high-speed vehicles. A better braking system will improve safety while driving. In general, the braking system used a friction principle. The friction appears between the disk pad and disk rotor. The friction on the disk pad and disk will cause damage on the surface of the braking components. The use of a friction-based braking system requires regular maintenance. The treatment is used to maintain the performance of brake components. In general, the brakes wear on the rapid braking process. The friction will affect heat generation, heat generated will be released to the environment. But, in a rapid braking process, the heat dissipation capability will decrease. The overheating disk will increase the risk of disk damage. The damage is caused by the braking behavior and the selection of materials used as brake components. Material changes will help improve braking performance. A good braking performance can be found when it is capable of high heat dissipation and wear resistance. A better material selection will change heat dissipation capability and has high wear resistance is very necessary. Besides the materials, the design of the brake components is also important. The use of a ventilated brake design with an additional heat pipe can reduce temperatures by up to 10% compared to conventional ventilated disks. This article will present a study about how to make the best design by providing a study about component properties characteristics.

As the modernization of marine transportation, it should be needed the strategy to improve the marine vehicle performances. The propeller is one of the important parts which has a function as an actuator during the operation of marine transportation or vehicle. The propeller design and optimization are packages to gain the best performances, included for the ducted propeller. Since the Nozzle design is one of the crucial aspects that influences the efficiency of the propeller. In the present study, the nozzle design has been proposed by using moving the propeller location based on the percentage of duct length. The propeller and nozzle were modelled in Computer-Aided Design (CAD) program packages and was testing to predict the performance using the OpenFOAM computational fluid dynamics (CFD) with Reynold-Average Navier-Stokes (RANS) method. A Kaplan type propeller is selected with 19A duct. The ducted propeller is analyzed by the Moving Rotating Frame (MRF). The computational results are validated by comparing with the experimental value of J from 0.2 to 0.8. The reasonable results were produced such the thrust, torque and efficiency trends were in good agreement with experimental data. According to the analysis, it can be concluded that by increasing 3% the duct length of the thrust increases about 2.148%

This paper discusses the effect of meshing size on wheel rim. It is not known that every design needs to consider the optimum result of the design, in reality the simulation cannot generates the optimal analysis due to several factors. One of the influencing factors in the simulation is the mesh size when simulating the wheel rim design. It is known that each mesh size gives different results, therefore it is necessary to do a calibration using finite element method from the benchmarking literature studies that have discussed this case before. Authors designed a vehicle wheel using Fusion360 and ran the simulating static analysis using ANSYS. The material used is steel and the boundary conditions of its design is angular velocity and load. The wheel designs were given different mesh sizes and resulted in stress (von-Mises) and displacement, since the results were analyzed for mesh convergence. For the convergence result, wheel rim has a von-Mises stress for 10 mm, 15 mm, and 20 mm size mesh is 164.38 MPa, 128.68 MPa, and 131.08 MPa, and the displacement is 0.16117 mm, 0.15592 mm, 0.15286 mm. The simulation made stress ratio for 1.174, 0.919, 0.936 and displacement ratio for 0.989, 0.957, 0.938. Through the use of different mesh sizes, different results can be proven, this is necessary to determine the convergence of the mesh used in the simulation. This paper proves that 10, 15, 20 mm size mesh convergence, with error ratio of displacement is 0.011, 0.043, 0.062 and the error ratio of stress is -0.174, 0.081, 0.064 to the benchmarking studies literature.

Fatigue failure is a phenomenon that often occurs in mechanical structures, especially in components that receive direct cyclic loading, e.g., marine facilities, automobiles, critical infrastructure, reservoirs, turbines, nuclear reactors, and features that work in extreme conditions. Several factors can affect fatigue resistance, including applied material type, environment temperature, microstructure state, residual stress, corrosion, and crack initiation. Accurately estimating fatigue life is critical. A variety of variables must be taken into the calculation to reduce the risk of dangerous failure. In this paper, a series of development and achievement reviews on the relevant phenomena and advanced research related to fatigue assessment is conducted. Consideration of fatigue assessment methodology, e.g., laboratory experiment and numerical calculation, is discussed to summarize relevant effects to characteristics of stress life, strain life, frequency-based, and fracture mechanic approaches. The review also presents the relationship of previous research and its relevance to the development of the recent study. The purpose of this paper is to provide state-of-the-art investigations as well as demonstrate the challenges of uncharted problems.

Thickness measurement is an important inspection aspect for several types of industries in the manufacturing process. One type of manufacture that requires thickness testing of its products is the braking pad industry. In general, industries use thickness testing with the ultrasonic method to obtain the thickness value and find out the defects of the product. Automatic testing allows the industry to check multiple specimens in one go. This research was designed and tested using finite element analysis on Autodesk Fusion360 software. The automatic thickness checking machine was applying a 3-axes mechanism with moving system parts using Festo Linear Actuator and Festo Servo Motor. The testing capacity of the automated machine is up to 5 brake pads and can be expanded based on the frame size and the Festo parts used on the design. The automated machine in this design was designed to perform thickness testing on the braking pad. The frame mechanism used in this study is an overhead crane with an aluminum hollow frame type that supports the whole mechanism. The frame was assessed by applying static load with value and type of load variations based on the loaded loads on each axis. The test results obtained in this test are the factor of safety, von-Misses stress, and also a displacement due to static loading.

Technology in the field of transportation has developed very rapidly turned to be one of the most challenging fields of engineering. Chassis is one of the important parts in the stability of a vehicle that used in automotive industry, because all components related to the stability attached to the vehicle chassis. The purpose of this research is to get the results of chassis simulation on a Ford AC Cobra ladder frame under the applied loads using Finite Element Analysis (FEA). This research was conducted in several stages of process, such as modeling chassis by Autodesk Fusion 360. The frame is going to be simulated with static loading by determining fixed constrains and then will be given the vertical force. The fixed constrains on the frame is clamped at both the front and rear wheel base. After assessment by finite element calculation, the maximum displacement is found to 0.3359 mm with 1.153 safety factor and the maximum von-Mises Stress of the chassis is 264.4 MPa. These results indicate that the designed chassis is capable to hold 4900 N vertical load and it still deforms in elastic condition and under allowable zone according to the applied material properties.

The rapid development of technology in the industrial center encourages the need for skilled and expert human resources. The industry always innovates in developing the quality of products to achieve the desired targets. One of them is a heater to heat a fluid, which one them is heat exchanger type. The most important part of the heater is the cathode heater coil or filament which is used to heat the cathode in a vacuum tube or cathode ray tube. Fabrication of coil heater products is interesting to study, which covers design, manufacture, and machining activities. This article discusses the fabrication process of the sulfur melter heating coil, which is carried out in one of manufacture industries. The research method is conducted by field survey to observe the design and fabrication process. Overall production stages are divided into the design stage which is to obtain technical illustration of the product, material selection stage which is to calculate and determine product material, manufacturing stage which is to determine the machining process of each product part, assembly stage which is to determine the type of jointing in each product part, and finally, the structural inspection stage which is to check the standard of fabricated products.

The world is being hit by a health crisis by the COVID-19 pandemic which has infected peoples across the globe. The cases of COVID-19 in Indonesia itself continue to increase every day. The transportation sector is one of the sectors that have experienced numbers of direct impacts as a result of large-scale social restriction in form of preventive regulation. Furthermore, this phenomenon causes health agencies to experience difficulties in distributing logistics for handling COVID-19, especially in water areas. In the era of the Industrial Revolution 4.0, various society aspects and industrial processes are digitally connected to increase productivity, especially for COVID-19 treatment and logistic handling. This research was conducted to analyze several proposed monohull-unmanned ship prototypes which are expected to be a proposed solution to assist COVID-19 countermeasure. A series of stability and motion analyses is conducted, then the results are assessed to conclude the best design among the proposed design options. Results of the study indicated that compared to three variations of hull types, design of the Model III has excellent characterisics of ship stability, hull resistance and seakeeping. These analysis parameters are considered as main criteria in the ship’s requirements since patient and logistic have to be transported safely to the designated location according to the given mission in assisting COVID-19 handling and treatment.

The industrial world requires advanced materials that have good mechanical properties, e.g., hardness with light weight, high toughness and high tensile strength characteristics. One of the known materials that is widely used and developed today is metal matrix composite (MMC). In general, metal matrix composite is produced by casting and powder metallurgy techniques. Metal matrix composites are one of the most promising materials for the future considering its design and performance. There are several potential applications for metal matrix composite in industries, i.e., the automotive, manufacturing process, aerospace, sports instrument, and the recreation industry. To maximize these advantages, metal forming processes are carried out in composites, such as forging, rolling and extrusion with the aim of improving their properties, minimizing porosity, obtaining shapes and sizes as needed, improving interfacial bonds between matrix and reinforcement. Based on state-development study in this work, it was found that the hardness and ultimate tensile strength (UTS) of the composite would increase after forging. Nevertheless, the ductility of the composite decreased after forging. The grain size will be reduced after the forging process and it becomes small after the forging process due to recrystallization during the forging deformation. As follow-up of this technical trend, this paper is extended to review various researches related to the effect of forging on the properties of aluminum matrix composites.

Advanced developments of design and structure industries require modern material which both complies with green environment issues to reduce non-renewable resources, and also has the prospect to be fundamental material. The aim of the research was to investigate the interaction between alkali treated of Salacca Zalacca Fiber (SZF) and High Density Polyethylene (HDPE) by using microscopic examination, chemical analysis, contact angle test, interfacial shear strength and flexural tests of composites. SZF was chemically treated using a 5% NaOH solution for 0, 1, 2,3, 4, and 5 h to modify the fiber's properties. Chemical analysis shows that hemicellulose was decomposed after alkalization-ray diffraction found that the crystalline index (CrI) was changed as a result of alkalization. Micrograph observations by scanning electron microscope (SEM) show the complete impurities removal and revealed the parallelly aligned cellulose microfibrils, while atomic force microscopy (AFM) result shows the decrease of surface roughness as seen in 2D roughness and 3D surface topography. Contact angle measurement was found that the contact angle decreases with increased treatment time which indicated the improvement on SZF wettability. From the IFSS test, it was found that the overall fiber-matrix adhesion of the composite was improved with peak adhesion obtained after 5-hour treatment.

Cavitation erosion is the most avoided problems caused by the bubble cavitation inception. Other frequent problems occurring are vibration and noise because of the cavitation induced pressure fluctuation on the hull. This paper aims to review the cavitation phenomenon on ship propellers, which have been performed in the previous research. Several techniques to obtain reliable observation and prediction of cavitation inception, related to the adverse effect on material damages are discussed through advance experimental laboratory and numerical modeling. Then, prediction and observation of cavitation behavior on the full scale and model scale, cavitation flow behind hull conditions, and geometry modification of the skew propeller are thoroughly discussed.