Abstract: The main objective of this work is to develop a 3D predictive model of Finite Element Analysis (FEA) to simulate and predict the bending force and the spring back behaviour of yellow brass alloy sheets (ASTM B36) in the V-bending process. To achieve this objective, the FEA program (ABAQUS/EXPLICIT) is used to create this numerical simulation for different values of the operating and the geometrical parameters (friction coefficients, bend radius, and opening die dimension). Furthermore, the effect of these process parameters on the bending force and the spring back behaviour is investigated by using the response surface method (RSM) in the V-bending process. Finally, the simulation results are shown that the investigated process parameters had much influenced on the bending force and the spring back angle in the V-bending process by finding the optimum design points using the predictive model of the response surface method.

Abstract: New Inverse Kinematic based Brain Computer Interface (IK-BCI) system was proposed. the system performs aim selection intended by user through acquiring user’s EEG signal, extract the signal’s feature, classify the intention behind the signal, and performs inverse kinematic on the predicted position to make the robotic arm be reached to the desired position. Three types of five-classes EEG mental tasks signals were acquired using EMOTIV EPOC EEG head set in separate sessions and compared in terms of online system’s performance after using each one as input signal. The proposed feature extraction method was hybrid feature extraction that include Multiclass Support Vector Machine (M-CSP) with Autoregressive (AR) coefficients features. Multiclass Support Vector Machine with Radial Basis kernel Function (SVM-RBF) was used for machine learning processing based on LIBSVM MATLAB library. Analytical solution was proposed to perform the Inverse Kinematic (IK) on 5-DOF Humanoid Robotic Arm (HRA) to be controlled in online basis. The practical results showed a successful cooperation between the IK and BCI with highest classification accuracy of 88.75% which leads to successful reach of the desired target.

Abstract: An increasing research dedication has been devoted recently to soft robotics. Soft robots are best known for their compliance and safety that nominate them substantially for human-centered applications. Robot-assisted surgical operations are expanding worldwide where soft robots find their potential way for this application. Soft robots are fabricated from highly nonlinear soft materials like silicone rubbers that exhibit complex combined hyperelastic, viscoelastic, and hysteresis behaviors. Dynamic modeling of soft robots that incorporate different soft materials with fiber-reinforcement involves many considerations and depends on the underlying design concept. Establishing a certain dynamic model can be valid for a certain design configuration that may not be applicable to another one. This work proposes a transient finite element analysis-based methodology for design and dynamic simulation of fiber-reinforced soft robots for minimally invasive surgery. This methodology is based on cohesive material testing and modeling paradigms and aims to found a generalized theoretical framework for the development and experimentation of soft robots. A multi-camera vision tracking system is proposed for monitoring the 3D soft robot moving trajectory. Experimental validation of the proposed methodology proves its reliability and accuracy for estimating the soft robot dynamic response upon different actuation scenarios. The suggested methodology can be utilized in the future for developing new soft robots, devising, and testing new dynamic models or control algorithms for soft robots.

Abstract: Now a day, the bimetallic sheet in metal forming processes are highly requested due to their characteristics and better mechanical properties than a single sheet. Unfortunately, the spring back phenomenon is one of the most phenomena that greatly affecting the dimensions and geometry of the V-bending process of the bimetallic sheets. For this purpose, the present work was conducted to study experimentally and numerically the effect of process parameters on spring back of Al/Cu bimetallic sheet in V-bending process includes the sheet thicknesses, equal punch and die radii, and strain rates. Firstly, it was proved that experimentally and numerically the setting position of Al die face/ Cu punch face setting condition experienced a smaller spring back value. In general, good agreement between experimental and numerical results was observed. Both results illustrated that positive and negative spring back are occurred due to changes in punch and die radii and sheet thickness, and with increasing their values the negative spring back is changed to the positive one as well as increasing the amount of spring back too. Also, with increasing the strain rates the amount of the spring back has either increased or decreased are greatly affected by sheet thicknesses and radii of the punch and die. Moreover, ANOVA analysis was conducted to determine the relative contribution and main effect of the process parameters on spring back. The ANOVA analysis shows that the bimetallic sheet thickness and punch and die radii are the significant parameters with P-value less than 0.05, while the strain rate is not a significant parameter, and has less influence on spring back than the other two parameters. Furthermore, a validated simulation model was developed to study the effect of using the die with a circular groove and the process temperature on spring back of the Al/ Cu bimetallic sheet. The simulation result provided that a die with a circular groove was experienced a less amount of spring back compare with simple V-die process and results in reducing the spring back amount in V- bending process of the bimetallic sheet. Also, the spring back amount is decreased by increasing the temperature in the V- bending process.

Abstract: Power plant consists of systems that effect on each other. The main two cycles in power plant are Water – Steam and Air – Gas cycles. Flue gas duct is used in air-gas cycle to release the flue gas from the furnace to the atmosphere. The cracks and holes occur in the gas duct because of corrosion, which resulted in allowing the air ingress into the duct and consequently cause a chemical reaction with flue gas, this reaction will create a sulfuric acid layer and hence accumulate on the internal surfaces of the duct and transfer to Induced Draft Fan (IDF). The main objective of this work is to introduce a composite layer to Corten Steel (the material from which the gas duct made) to improve a corrosion resistance. This coating layer consists from serval nanoparticles (ZnO, ZrO2, SiO2 and NiO) as reinforcement phase with epoxy resins matrix. The surface roughness profiles of Nano-epoxy composite coating show an improvement in surface roughness compared to the original Corten Steel without coating. Furthermore, XRF analysis shows the Nano-epoxy composite coating element and the increment of element that improve corrosion resistance.

Abstract: Fossil fuel consumption and harmful emissions increase led to intensive search for alternative fuels. The present oil was extracted from Egyptian jatropha nuts by using a designed and manufactured screw press at a preheating temperature of 100°C and operational screw speed of 60 rpm. Esterification followed by transesterification produced biodiesel from jatropha oil. Heat recovery from exhaust gases at a temperature of 90°C was utilized to preheat the produced jatropha oil. Jatropha biodiesel was preheated to a temperature of 40°C. Measured properties of preheated biodiesel and jatropha oil were found to be within ASTM standards. The present research studied the performance and emissions of a diesel engine burning preheated biodiesel and bio oil compared to diesel fuel. Experimental tests were carried out from zero to full load. The results revealed that about 2% decrease in the brake specific fuel consumption and 2% increase in the brake thermal efficiency for preheated jatropha oil compared to diesel oil. Preheating of jatropha oil resulted in CO and smoke emissions reductions by about 51 and 55%, respectively in comparison to conventional diesel oil. Jatropha oil and biodiesel preheating reduced NOx concentrations by up to 35 % and 7% respectively at 75% of engine load with respect to unheated fuels. Preheated jatropha oil showed better engine performance in comparison to other fuels. Preheated jatropha oil is recommended to be used as an alternative fuel in diesel engines.

Abstract: The challenges faced by the electricity industry in Indonesia at present with a considerable generating capacity. One of them is the problem of variations in coal calories and fuel prices. Besides that, it also relates to the amount of generating capacity which has an impact on the amount of NOx gas release which has the potential to disturb the environment. By understanding the mechanism of optimization and setting of the pulverizer in this case the primary air velocity settings that coming out of each pulverizer output line can improve the performance of the generator itself and reduce NOx gas. By setting the primary air velocity at the outlet the process of forming fireball is more perfect which influences a better combustion process. Thus, the purpose of this research is to obtain the condition of setting the primary air velocity so that it causes the combustion process to produce exhaust gas with NOx content that meets the applicable criteria. In this study the Computational Fluid Dynamics (CFD) method is used. The boiler geometries are made using Gambit software and for numerical simulations using ANSYS Fluent software 19.2. For validation, the initial simulation results for the current boiler conditions are compared with actual measurement data. Furthermore, it will be simulated by varying the primary air velocity. The simulation results show that the effect of increasing in velocity outlet of pulverizer on the combustion temperature in the furnace (without changing secondary water) is inversely proportional. The greater the velocity outlet pulverizer, the lower the combustion temperature in the furnace. So that the recommended model design is a variation of the velocity outlet of pulverizer with a speed of 28 m/s because it has a superheater inlet temperature slightly above the existing model, so that the use of superheater and reheat spray only slightly adds to the existing model while for NOx mass fraction boiler output is around 65% of the existing model.

Abstract: Fundamental study to quantitatively evaluate not only the root-mean-square (rms) roughness Rq but also skewness Rsk of non-Gaussian random rough surfaces by ultrasonic method is presented. In this work, Johnson distribution together with Kirchhoff theory have been employed to derive a newly proposed Johnson characteristic function, which provides a theoretical relationship among ultrasonic reflection coefficient, Rq and Rsk. Based on the characteristics of such relationship, an effective ultrasonic measurement method consisting of a pitch-catch and a pulse-echo configuration to quantitatively characterize Rq and Rsk has been proposed. A general guideline for such characterization method has also been suggested. The validation of the proposed method has then been conducted numerically in the case of an air-coupled ultrasound. Good agreements between the numerically estimated Rq and Rsk and the corresponding reference values thus confirm the validity of the proposed method.

Abstract: This paper presents a hybrid control model, which is based on the Hybrid Automata (HA) and real-time Unified Modeling Language (UML) to systematically and homogenously implement cooperative controllers for an Autonomous Surface Vehicle (ASV) combined with Multiple Autonomous Underwater Vehicles (MAUVs) operating in the team. The paper brings out the main points as follows: the dynamics of an individual underwater vehicle are adapted for control; the coordinated operation scenarios, hierarchical control architecture and the Hybrid Cooperative Control Model (HCCM) are proposed to capture the control requirements for an ASV-MAUVs team. The HA’s features are specialized for modeling the global control algorithms of ASV-MAUVs cooperated in the team; the specialized HA of HCCM is then implemented for the team-based cooperative operations of the ASV-MAUVs team by using the real-time UML. Finally, a cooperative controller permits a team of a small-scale ASV combined with 03 AUVs to perform pre-determined search scenarios with the coordination mechanisms for ocean exploration, was designed and simulated. In this application, the implementation model was converted into the simulation environment by using an open-source platform of OpenModelica to quickly perform the simulation model for the controller. The obtained simulation results could allow us to verify and evaluate the proposed control model with good reliability and feasibility.

Abstract: Many researchers have been tried to discuss the parameters that used to enhance the heat transfer rate within different shapes of enclosure that exerted by an external magnetic field with a lid driven. So, in this research, combined effect of non-Newtonian fluid that contains Nano-particles Al2O3 within new square enclosure heat geometry shapes (four cases that will be elaborated in this research: case I :small wavy notched shape, case II: small semicircle notched, case III: bigger semicircle notched and the last one case IV has a large wavy notched) have been solved numerically by finite element method that base on the Galerkin weighted residual formulation where used in COMSOL Multiphasic under a relevant dimensionless parameters: 0.001  Ri  1, 0  Ha  60, solid volume fraction 0    0.1, power law index 0.2  n  1.4, Grashof number Gr=100. However, the innovation of the boundary conditions are a new heating geometry shape wall has an alternating effect with the variation of the power index parameters and Richardson number. It can be shown that case II of small circular notched is the best cases that justified of improving forced and mixed convection heat transfer. The magnetic field strength interplay negative effect on improving the forced convection flow within the enclosure. The average Nusselt number increases by evolution of the power law index value while independent on the shape geometry of the heating cavity wall.

Abstract: Nowadays, the need for energy in Indonesia increases related to population growth rapidly where it leads to degrading the reliability of the power system operation. Meanwhile, conventional energy reserves such as oil, coal, and others are running low. Therefore, the usage of alternative energy that categorized as green technology and promising energy in the future is a must. One of the most potentials of those energy technologies is a wind power generation. Generator, a component of wind power plant, is having the function to convert mechanical energy into electrical energy. Due to the intermittent of wind power generator output affected by the weather circumstances, a converter device namely a buck-boost converter was utilized as control of the wind generator to increase or decrease the voltage depending on the desired voltage on the system. To enhance the performance of the buck-boost converter, intelligent control namely fuzzy logic controller (FLC) was employed as feedback control of the converter. Here, error and delta error signals of the converter were utilized as the input data of FLC while the duty cycle of the converter was employed as output data of FLC. In this research work, the proposed control model has designed to work for blade rotation within the range of 192-364 rpm. From the simulation results, the performance of the converter controlled by FLC had obtained the time delay of 0.037 s, found the time up of 0.159 s, produced the peak time on 0.354 s, attained the overshoot of 1.07 %, and reached the time for steady-state on 0.164 s. Meanwhile, when the proposed control model had connected to the hardware, it had resulted on 2.6 s for the delay time, produced the uptime of 3.5 s, found the peak time of 4.9 s, achieved the time for steady-state on 3.2s and generated the steady-state error of 1.92 %.

Abstract: The objective of this research is to investigate the effect of the machining parameters on the surface texture and the surface residual stresses distribution for AL2024-T351 in the face turning process. Experimental work is carried out on samples of AL2024-T351 for the face turning process at different machining parameters of cutting speed and feed rate with a constant depth of cut. 3D Optical Microscope is used to assess the surface topography for the machined samples. 3D–simulation model developed for plane stress finite element modeling of a pure orthogonal cutting process for Al2024-T351 at different machining conditions. In this research, ABAQUS/Explicit package was used to predict the surface residual stress distributions in the face turning process at different cutting conditions. Finally, correlations are made between the measures of the surface roughness and the finite element analysis results to predict the optimal trend of machining parameters for quality surface finish and minimum surface residual stress.

Abstract: In this study, Friction Stir Welding process is applied to weld two plates of AA5052-H111 as a butt joint using Stepped and Tapered pin profile tools. Design of Experiment is planned by Minitab17 for the welding conditions; Welding Speed (W.S), the Rotational Speed (R.S), Tool Tilting Angle (T.A) and the tool design. Visual and mechanical (Tensile UTS and microhardness VHN) tests are carried out then the multi-response optimization based on Taguchi-method is performed to identify the highest effect of these parameters. At welding conditions; R.S 1600 rpm, W.S 17mm/min and T.A 2° using the stepped tool, the UTS and VHN are optimum and extend to 90.5% and 150% of the base material, respectively. By observing the resulted samples; the usage of Stepped tool contributes to the smooth surface and helps in the good appearance of the weld quality. Also, the welded samples using the Tapered tool obtains higher hardness.

Abstract: Since the shaft is an important part of all machines, it is deemed very necessary to design it effectively. The whole shaft design involves several iterative steps beginning with the determination of the shaft's preliminary dimensions. This paper introduces software that is based on a new integrated method of stress, deflection and critical speed analysis to determine the optimal dimensions of different stepped shafts. This software was developed with the help of a graphical user interface and visual aids using MATLAB as a programming language. In order to determine the optimal shaft diameter, the fatigue stress analysis is conducted at the most critical locations automatically. Analysis of deflection is then performed to check whether the resulting dimensions are safe or not. The study of vibration is also conducted to test whether the shaft runs safely away from critical ones. Verification is also carried out on the basis of a comparison between the proposed design and the Shigley design on a given case study, which shows that the new approach used in the proposed design leads to more accurate results. The proposed software greatly serves any user who has no experience or knowledge of different design techniques and strategies, resulting in time, effort, and cost savings.

Abstract: The present work deals with a study highlighted on the cylindrical deep drawing process of AA2024-T4 aluminum alloy. The influence of different weight percentages of Nano powder additives (MoS2 and CuO) added to sunflower and HD50 oils had been experimentally investigated. A constitutive finite element model was constructed for 3-D simulation cup product of the deep drawing process by using Commercial ANSYS V.18 (Workbench LS-DYNA model) software to assess the influence of coefficient of friction of these Nano particle additives on the forming force, thickness distribution, spring-back, forming limit diagram (FLD) and percentage of thinning ratio. An elastic – plastic behavior according to Cowper Symonds power law hardening, assuming isotropic properties was used to simulate the plasticity behavior of AA2024-T4 aluminum alloy during the deep drawing process. For the validation, the experimental results were compared with numerical simulation results. The results show that the blank holder force should be equal 20 KN to prevent occurring the wrinkling and cracking in the deep drawing product. The MoS2 Nano particle additives reveal good results in compared with CuO Nano particle additives while using hybrid Nano additives gives best quality of the deep drawing product than using MoS2 or CuO individually as a lubricant additives. Design of experiment (DOE) according to Taguchi method was used with the aid of Minitab program to verification for the experimental and numerical results.

Abstract: The objectives of this study were to design and simulate an aluminum sand casting process of air compressor fan blade, which had thin disc and fins. The finite difference analysis (FDA) was conducted to predict the fluid flow and defect during cast process. The experimental work in a commercial foundry was used to validated the FEA results. This study was conducted in three phases. It started from design, simulation, and experimental validation. SOLIDCast software was selected for designing the mold and rigging system as well as defining the mesh. The software adopted a finite difference method as the basis of calculation. From FDA, it showed that a 10mm diameter of down sprue was able to flow the molten aluminum and fill in 100% of the cavity within 3 seconds without premature solidification. The output criteria of solidification time and critical fraction solid time had confirmed good directional solidification without any isolated pool. The material density criteria displayed 30% porosity around the disc surface. In the experimental work, the casting process completed in approximately 2.5 seconds. The casted fan blade was then cut into pieces at the location where the simulation identified potential defects for defect analysis under Photo Micro. The simulation results were found to be in good confirmation when compared with the experimental trial. The defects could be predicted during the simulation, and hence optimization could be done before the actual casting in foundry.