Determination of Barreling of Aluminum Solid Cylinders During Cold Upsetting Using Genetic Algorithm

This study presents Genetic Programming models for the formulation of barreling of aluminum solid cylindersduring cold upsetting based on experimental results. The maximum and minimum radii of the barreledcylinders having different aspect ratio (d/h= 0.5, 1.0 and 2.0) were measured for various frictional conditions(m=0.1-0.4). The change in radii with respect to height reduction showed different trends before and afterfolding, therefore, the corresponding reduction ratios of folding were also determined by using incrementalupsetting. Genetic programming models were prepared using the experimental results with the input variablesof the aspect ratio, the friction coefficient, and the reduction in height. The minimum and maximum barrelingradii were formulated as output taking the folding into consideration. The performance of proposed GP modelsare quite satisfactory (R2 = 0.908-0.998).Keywords: Upset, forging, barreling, bulging, axisymmetric compression

Experimental and Numerical Investigation on Effects of Pin Diameter on Multi-Point Forming

Multi-point forming (MPF) is an advanced and flexible method to form sheet metal workpieces. Although there are studies investigating different aspects of this method, the studies on the effects of pin diameter on sheet and pin contact on MPF are insufficient. In this study, pins with diameters of 10, 12, and 14 mm were used to investigate the damage factor, effective stress distribution, and required forming loads of three forms of aluminum 1100 parts in finite element simulations. In addition, experimental works were conducted for the 12 mm pin and the forming loads and the thinning on the contact points of pin and formed sheet metal parts were compared with the simulations. The 14 mm pin forming provided the highest effective stress distributions and the damage factors of 0.448, 0.770, and 0.329 were obtained for form1, form2, and form3, respectively. The percentage errors between experimental works and simulations using 12 mm pin forming were calculated as 7.4, 5.1, and 2.4% for all forms 1 to 3. In conclusion, pin diameter was shown to have significant effects on the MPF process. Larger diameter pins resulted in higher loads and tearing of sheet metal

Experimental and Numerical Investigation on Effects of Pin Diameter on Multi-Point Forming

Multi-point forming (MPF) is an advanced and flexible method to form sheet metal workpieces. Although there are studies investigating different aspects of this method, the studies on the effects of pin diameter on sheet and pin contact on MPF are insufficient. In this study, pins with diameters of 10, 12, and 14 mm were used to investigate the damage factor, effective stress distribution, and required forming loads of three forms of aluminum 1100 parts in finite element simulations. In addition, experimental works were conducted for the 12 mm pin and the forming loads and the thinning on the contact points of pin and formed sheet metal parts were compared with the simulations. The 14 mm pin forming provided the highest effective stress distributions and the damage factors of 0.448, 0.770, and 0.329 were obtained for form1, form2, and form3, respectively. The percentage errors between experimental works and simulations using 12 mm pin forming were calculated as 7.4, 5.1, and 2.4% for all forms 1 to 3. In conclusion, pin diameter was shown to have significant effects on the MPF process. Larger diameter pins resulted in higher loads and tearing of sheet metal

The 2D Finite Element Microstructure Evaluation of V-Shaped Arc Welding of AISI 1045 Steel

In the present study, V-shaped arc welding of the AISI 1045 steel is modeled by using 2D Finite Element Model (FEM). The temperature distribution, microstructure, grain growth, and the hardness of the heat-affected zone (HAZ) of the welding are simulated. The experimental work is carried out to validate the FE model. The very close agreement between the simulation and experimental results show that the FE model is very effective for predicting the microstructure, the phase transformation, the grain growth and the hardness. The effect of preheat temperature on the martensite formation is analysed, and it is shown that 225 °C preheating completely eliminates the martensite formations for the 12 mm thick plate