The manufacturing industry plays an important role in a country's economy because it can produce high-value products and has the opportunity to create jobs for local communities. In this study, the authors designed a horizontal shell core casting machine for small and medium enterprises in the automotive sector with a productivity of 60 seconds per cycle of products is designed based on requirements needed. This shell core casting machine is a device to produce shell core molds used to manufacture automotive components and parts. The design of this device was focused on engineering design in the form of 2-dimensional drawings and computer aided design models in 3-dimensional form. This study was done in collaboration with a local machinery manufacturer in Karawang district in Indonesia. It is expected from these designs will become a reference to manufacture shell core casting machines to support national industrialization impacted on improving the local community's economy.

Issues in friction stir spot welding focus mainly on the mechanical characteristic affected by its Hardness. This Hardness must be maintained by evenly temperature distribution in weld zones during welding. The process parameters are mainly responsible for the development of the hardness of the friction stir spot weld. This study presented the hardness evaluations on the friction stir spot weld via the Hardness-Vickers test and analysis of the temperature distribution in the weld zones via the finite element method. The workpiece samples used in this study were Aluminium alloy 5052-H112 with a thickness of 2 millimeters in the lap-shear mode based on 3 main parameters at low and high levels of parameters configuration. The results obtained via the Hardness-Vickers tests exhibited a value of 42-HV located in the middle of the spot-weld center using a low-level parameters configuration. This value increased to 64-HV around the vicinity of the keyhole. And then the value decreased to 53-HV outside the keyhole, about 6 millimeters from the spot-weld center. Using high-level parameter configuration, the Hardness-Vickers value increased to 61-HV in the middle of the spot-weld center. The value then increased to 76-HV in the vicinity of the keyhole. Furthermore, the value decreased at 60-HV outside the keyhole, which ca 6 millimeters away from the spot-weld center. The temperature distribution of the weld zones achieved 480 oC in the vicinity of the keyhole using the low-level parameter configuration. Slowly, the temperature declined to 380 oC at 6 mm away from the friction spot-weld center in the HAZ. Using the high-level parameters configuration, the temperature distribution reached 540 oC in SZ, and slowly reduced to 425 oC in HAZ. Based on the results, it was found that by using high-level parameters configuration the hardness of the friction stirs spot weld exhibited better Hardness-Vickers value and evenly temperature distribution in the weld zones.

Traffic congestions problem could affect everyday life especially in urban area.In order to solve the issue, an excellent traffic flow prediction needs to be developed for a better traffic management.Hence, this study was conducted in order to predict traffic flow by using the data of total volume of vehicles per hour at two main roads located in urban areas namely Selangor and Kuala Lumpur, Malaysia by using application of chaos theory.Phase space reconstruction was used to determine the chaotic behaviour of the total volume of vehicles per hour data.The reconstruction of phase space involves a single variable of the total volume of vehicles per hour data to m-dimensional phase space.Meanwhile, the inverse approach as well as local linear approximation method was used to develop prediction model of the traffic flow time series data.This study found that (i) the time series data were chaotic behaviour based on the phase space plot and (ii) inverse approach can provide prediction on the traffic flow time series data besides give excellent prediction with the value of correlation coefficient more than 0.7500.Hence, inverse approach of chaos theory can develop to prediction model towards the traffic flow in urban area; thus may help the local authorities to provide good traffic management.

In an initiative to reveal the property of welded joint, investigation and assessment of the welding parameters in friction stir spot welding (FSSW) was carried out. In this study, the AA5052-H112 sheets with 2mm thickness was welded using cylindrical tool pin profile under different combinations of main process parameters i.e. spindle speed, tool depth, and dwell time. The fatigue test under cyclical load condition was performed to investigate the dynamic behavior of the welded joint. Failure mode analysis on the fracture of the weld joint after fatigue test was took also consideration. Finally, results from the test were evaluated using analysis of variance (ANOVA) to deter-mine statistically significant factors and associated percentage contribution together with the generation of main effects plots. From ANOVA results, dwell time had the highest influence on fatigue load with a PCR of 52.8%, followed by the spindle speed 37.1%, and then tool depth 6%.

The parameter of angular speed, depth of tool, and time of dwell of friction welded spot was studied on the alloy of aluminium. To do so, the impact from parameters was investigated through tensile shear test on the welded alloy and using the design of experiment (L8). ANOVA is then used to see important factors and contributions via main effects plots. It was found that angular speed of tool had a big impact on tensile shear load with 45 %, time of dwell 34 %, depth of tool 10 %. The angular speed of 1 400 rpm, time of dwell 9 s, and depth of tool 3.5 mm were the optimal parameters in this study. Keywords: light material welding, optimize weld process, weld softened material

The cost and efficiency of experiment and test are still a major issue in manufacturing especially in welding. In this study, a machine learning technique i.e. support vector machine (SVM) was applied to develop a load level prediction system of friction stir spot welded joint aluminium alloy AA5052-H112. This load level prediction system model was proposed based on three levels of load group of the welded joint. Experimental works in friction stir spot welding was conducted on samples specimens of AA5052-H112 2mm thick overlap joint based on 27 combinations of governed parameters i.e. spindle speed, tool depth, and dwell time. Mechanical testing of tensile shear load was then carried out to those specimens to obtain 27 loads data to form the SVM classifier. These data were required for pattern classification and model development via training and testing the proposed prediction system. The result obtained via training and testing showed the classification of load data produced by the proposed system, matched to the required load level with the 100%. This study proved that the proposed load level prediction system offered a useful tool to predict the load level of friction stir welded joint aluminium alloy AA5052-H112 by using respected parameters without required experiments and tests.

Optimization of the process was still the issue in manufacturing. Investigation on the process parameters that effects to the property of welded structure were necessary. In this study, the AA5052-H32 sheets of 2 mm thick were welded using friction stir spot welding (FSSW) and tested via tensile shear load test to investigate the influence of spindle speed, tool depth, and dwell time to the tensile shear load of the joints. The result shows that in every set of parameter combination, exhibit interesting influence to the tensile shear load. The effect of spindle speed of 1000 rpm shown the good property in average 18.33 KN especially at tool depth of 3.5 mm. Furthermore, the effect of tool depth brought significant effect to the tensile shear load especially at 3.5 mm for each set of spindle speed and dwell time. The set of dwell time to parameter combination had no significant effect to the tensile shear load. The good tensile shear load could be achieved in the range of 17.7-19.3 KN at 3.5 mm of plunge depth and 1000 rpm of spindle speed, where the best one was 19.3 KN at 7s of dwell time.

Friction stir welding (FSW) is a promising joining process that offers a high potential to be widely applied across industry sectors such as automotive, shipbuilding and aerospace. Nevertheless the path force can vary significantly due to the fluctuation of workpiece temperature and other process variations, thus results in inconsistency in weld microstructure. This paper describes the system integration of a FSW machine with a focus on the development of a traverse controlled table in order to produce a consistent temperature and path force along the weld path in FSW process. Aluminium alloy 6061 plate and a FSW's tool with a flat shoulder and conical pin without thread are used. Advantages of such an approach include wormhole generation will be eliminated, a high quality of weld microstructure can be produced and the synchronization between the temperature and path force can be obtained.

Friction stir welding (FSW) is a relatively new solid-state joining process which is considered energy efficient, eco-friendly and versatile. High stress and strain occur at the rotating tool, consisting of a pin (probe) and a shoulder, during the friction stir process. The geometrical design of the tool has some impact in terms of stress and strain once static load is applied against the tool. In this work, specific stress can be found on the tool due to the plunging and travel process that is analysed using finite element method. In the present work, a steady state finite element stress analysis of friction stir welding was carried out using CATIA V5 software. The critical points of the FSW tool are located mainly on the edge between the shoulder and the pin, where a large amount of stress is found and further leads to failure or tool defects. This critical stress and strain can be reduced by enlarging the diameter size of the pin and increasing tool life.

A three-dimensional (3D) finite element model was created to simulate the friction stir welding process of 6063-T5 aluminum alloy. The analysis studies the fundamental knowledge of FSW process with respect to temperature difference in material to be joined and to simulate the temperature distribution in the workpiece as a result of a Friction Stir Welding. The simulation uses HyperMesh and HyperView solver from Altair Hyperworks. The simulation provides better understanding for the peak temperature distribution in the friction stir process. Two cases have (i) constant traverse speed, but varying been simulated rotational speed, and (ii) constant rotational speed, but varying traverse speeds. Simulation results show the peak temperatures increased when the traverse and rotational speeds were increased.