Impact Mechanics
Farshid Kholoosi; Saman Jafari; Mahdi Karimi
Abstract
In this study, the crushing behavior and energy absorption of various thin-walled structures under quasi-static loading are investigated. Some experimental data from similar work are used for the validation of a simulated model. Some samples are designed and considered with different combined geometries. ...
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In this study, the crushing behavior and energy absorption of various thin-walled structures under quasi-static loading are investigated. Some experimental data from similar work are used for the validation of a simulated model. Some samples are designed and considered with different combined geometries. It was found from simulated model that the most ability of specific energy absorption and crushing force efficiency are related to the circle-square sample. For the circle-square sample, the analytic equations for calculating the mean crushing force are obtained. The mean crushing force result is compared with the result of simulations, showing a good agreement. The multi-objective optimization process for the circle-square structure is performed using non-dominated sorting genetic algorithms for two statuses. The purpose of optimization is to increase the specific energy absorption and to decrease the peak crushing force, which causes the increase of the crushing force efficiency amount. The amount of specific energy absorption in the second status compared to the first status is improved by 17%. The amount of crushing force efficiency is improved by 12% after the optimization process.
Welding
Saman Khalilpourazary; Reza Abdi Behnagh; Ramezanali Mahdavinejad; Nasib Payam
Abstract
This study focused on the optimization of Al—Mg to CuZn34 friction stir lap welding (FSLW) process for optimal combination of rotational and traverse speeds in order to yield favorable fracture load using Grey relational analysis (GRA). First, the degree of freedom was calculated for the system. ...
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This study focused on the optimization of Al—Mg to CuZn34 friction stir lap welding (FSLW) process for optimal combination of rotational and traverse speeds in order to yield favorable fracture load using Grey relational analysis (GRA). First, the degree of freedom was calculated for the system. Then, the experiments based on the target values and number of considered levels, corresponding orthogonal array, Grey relational coefficient and Grey relational grade were performed. In the next step, Grey relational graph of each level was sketched. The performed graph and analysis of Grey results proved the impact of rotational speed and traverse speed on fracture load of resultant joints. Finally, the optimum amount of each parameter for better strength of the welds was obtained. This study showed feasibility of the application of Grey relational analysis for achieving dissimilar friction stir lap welds with the highest quality.
Manufacturing Processes
S. Khalilpourazary; P. M. Kashtiban; N. Payam
Abstract
Nowadays, in order to reach minimum production cost in machining operations, various optimization methods have been proposed. Since turning operation has different parameters affecting the workpiece quality, it was selected as a complicated manufacturing method in this paper. To reach sufficient quality, ...
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Nowadays, in order to reach minimum production cost in machining operations, various optimization methods have been proposed. Since turning operation has different parameters affecting the workpiece quality, it was selected as a complicated manufacturing method in this paper. To reach sufficient quality, all influencing parameters such as cutting speed, federate, depth of cut and tool rake angle were selected as input parameters. Furthermore, both surface roughness and tool life were considered as the objectives. Also, ST37 steel and M1 high speed steel (HSS) were selected as workpiece material and tool, respectively. Subsequently, grey relational analysis was performed to elicit optimal values for the mentioned input data. To achieve this goal, first, degree of freedom was calculated for the system and the same experiments were performed based on the target values and number of considered levels, leading to calculating grey relational generating, grey relational coefficient and grey relational grade. As the next step, the grey relational graph was sketched for each level. Finally, optimum values of the parameters were obtained for better surface roughness and tool life. It was shown that the presented method in the turning operation of ST37 led to high surface quality and tool life.
Manufacturing Processes
R. Arokiadass*; K. Palaniradja; N. Alagumoorthi
Abstract
Metal matrix composites have been widely used in industries, especially aerospace industries, due to their excellent engineering properties. However, it is difficult to machine them because of the hardness and abrasive nature of reinforcement elements like silicon carbide particles (SiCp).In the present ...
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Metal matrix composites have been widely used in industries, especially aerospace industries, due to their excellent engineering properties. However, it is difficult to machine them because of the hardness and abrasive nature of reinforcement elements like silicon carbide particles (SiCp).In the present study, an attempt has been made to investigate the influence of spindle speed (N), feed rate (f), depth of cut (d) and various %wt. of silicon carbide (S) manufactured through stir cast route on tool flank wear and surface roughness during end milling of LM25 Al-SiCp metal matrix composites. Statistical models based on second order polynomial equations were developed for the different responses. Analysis of variance (ANOVA) was carried out to identify the significant factors affecting the tool flank wear and surface roughness. The contour plots were generated to study the effect of process parameters as well as their interactions. The process parameters are optimized using desirability-based approach response surface methodology.
