In this paper, first design and analysis history of full metal CNG cylinders for vehicle are investigated. Next with respect to the CNG worldwide standards, a full metal type cylinder is designed and analysed. Then the numerical analysis results and practical results are compared, and the correctness of the investigation is verified. In the end, the most suitable alloy with respect to the dimensions for the purpose of manufacturing of such cylinders is suggested. Manuscript profile

Abstract: Nowadays, the non-traditional processes such as “LASER, EDM and AWJ” used for cutting high thickness sheet metal. Hardox is hard and tough steel alloy and it has many industrialize applications. One best process to cut the Hardox is abrasive water jet (AWJ) cutting.  It can cuts complex shape with high quality and accurate tolerance.  AWJ cutting offers certain unique benefits such as negligible heat affected zone, high degree of manoeuvrability in cutting process and less machining force exertion.  In this research work, first, the effective cutting process “AWJ” parameters were identified.  Then, to determine optimum Hardox cutting parameters, some experimental tests were undergone.  Finally, the experimental results were analysed using “ANOVA” technique in order to determine regression equations for achieving optimum parameters to set-up equipment for Hardox steel cutting. Manuscript profile

On account of some complexities such as fluid-structure interaction and extra-large deformation problems, complete simulation of abrasive water jet cutting process is very hard. The main goal of this paper is to overcome these difficulties through comprehensive simulation in LS-DYNA commercial software. For this purpose the Smoothed Particle Hydrodynamics (SPH) and Arbitrary Lagrangian Eulerian (ALE) methods are employed. Utilizing these methods, the depth of water jet penetration and mechanism of erosion are simulated for a certain test case. In addition, the effect of water pressure and traverse speed on depth of penetration are examined. Comparison between the obtained results using both methods showed that the numerical results are in good agreement with available experimental data. Manuscript profile

Studying the formability of the sheet metals have been the subject of many researches during the last decades. A number of experimental and numerical approaches were implemented to derive the formability diagrams of different materials. In this study, the formability of two mostly used alloys, Brass 260 and Al5182-O as low and moderate formability materials, were investigated respectively. The forming limit diagrams of both materials were determined by using three experimental approaches such as Nakazima quasi-static as low strain rate method, hydrodynamic forming method as the moderate strain rate method and Electrohydraulic Forming process as high strain rate method. Three experimental results of forming limit diagram with the various strain rate were compared graphically. The results have shown that both of the materials could withstand higher strains when the electrohydraulic forming method was applied on the specimens and consequently, the forming limit diagrams for Brass 260 and Al5182-O shift up by 11% and 14%, respectively. In addition, it was concluded that the hydrodynamic forming method improves the formability of the materials by 4% and 6% for Brass 260 and Al5182-O, respectively. The outcomes of this study indicated that the formability of both materials was improved significantly by increasing the strain rate. Manuscript profile

CNG vessels are used in many vehicles. Mass production of CNG pressure vessels requires exact understanding of process effective parameters. In this paper, the numerical analysis has been used to study the manufacturing parameters. The entire manufacturing processes, including deep drawing, redrawing and ironing, of an aluminum liner sample of CNG pressure vessel (without spinning) have been simulated by Finite Element technique. The deep drawing process has been modeled by using flat dies. Then, drawing force and wall thickness variations have been studied. In order to achieve the final diameter of the liner, the redrawing process has been implemented in a flat die. To obtain a uniform wall thickness, the ironing process has been simulated in two stages, and the required force and the change of wall thickness for each process have been recorded. The results of this paper have been compared with the published results obtained by other researcher and found a good correlation between them. Manuscript profile

Three important parameters in designing a closed die for forging process are ratio of width to flash thickness, ratio of height to billet diameter and the friction factor. In this paper the influences of these parameters on the required force for the forging and percentage of die filling were investigated. It was found that by controlling the flash dimension, the material loss is reduced and the percentage of die filling is increased. Also, an experimental model was simulated and analyzed by finite element method. To validate the numerical results obtained by this research, value of gained force from finite element method was compared with the obtained experimental results. In order to coordinate and connect between the mentioned parameters and obtain a performance function, a two layer neural network was used. Finally, by using neural network and genetic algorithm, the optimum sets of parameters which minimized the force and maximized the percentage of die filling were found. These values were compared with the experimental results of other researchers. The genetic algorithm has good correlation with the experimental method as well as it has presented acceptable estimation for effective parameters in the forging process. Manuscript profile