In the present study, the effects of process and geometrical parameters on the maximum temperature of tool have been investigated. Simulation of mild steel machining process in different cutting depths, speed of rotation (SOR), feeding rates, and different rake angles was performed. To verify the simulation, numerical results were compared with experimental results. Based on the results, it was found that by increasing the speed of rotation at a constant cutting depth and a constant feed rate, the maximum temperature of the process experiences a significant increase. By increasing the depth of the cut, the geometric location of the workpiece maximum temperature was transmitted to the edge of the tool and surface changes occurred, which it was accompanied with increment in the depth of the cut. The tool with the rake angle of -10° and the depth of cutting of 2 mm had the highest recorded temperature due to the lack of sufficient space for removing chips from the work surface. پرونده مقاله

In this paper, analytical and finite element solutions of mechanical buckling of a thick Functionally Graded (FG) plate have been investigated. Boundary conditions have been assumed as simply supported at all edges and three different loadings have been applied. In analytical section the procedure of developing the critical buckling force by third order shear theory has been presented and then the stability Equations have been reduced from 5 to 2. In continue, the problem has been solved using numerical simulation by ABAQUS. To validate the FEM, results have been compared and validated with analytical solution. The results show that the bi-axial compression loading case with the loading ratio of R to one and R to zero are the most possible and most unlikely case in buckling occurrence, respectively. پرونده مقاله

In this research, the impact behavior of nanocomposite sandwich panels with epoxy/fiberglass/nanosilica face sheet were assessed by the finite element method. In the first step, the mechanical properties of the nanoparticle-containing composite should be obtained. A unit cell of fabric was designed in Catia software and placed within the designed polymeric matrix. The mechanical properties of this unit cell were defined as a new matrix and the nanoparticles were randomly dispersed in the new matrix using a Python code. The elastic properties of the modeled nanocomposite were obtained using Abaqus software via applying periodic boundary conditions based on the mean volumetric stress. In the next step, the sandwich structure was subjected to impact loads at various speeds and contact force-time diagrams were plotted using Abaqus software. The modeled results were compared with the known experimental data which showed a high accuracy in predicting the mechanical properties and impact behavior of the nanocomposite sandwich structures. پرونده مقاله

In this research, two methods of conventional Friction Stir Welding (FSW) and two-pass friction stir welding have been used to weld AA6061-T6 alloy parts with a copper interlayer (copper foil. Based on the results, it was determined that the number of welding passes, the presence or absence of copper foil as an interlayer, the number of welding passes, the direction of tool rotation and the direction of tool movement in the second pass strongly affect the strength and ductility of FSW. According to the results, the highest tensile strength and ductility belong to TP-D(Two-Pass, type D), TP-B(Two-Pass, type B), TP-C(Two-Pass, type C), TP-A(Two-Pass, type A), CF-Cu and CF(Conventional FSW) samples, respectively. The mentioned samples have growth of 21, 29, 45, 36 and 58% respectively compared to the CF sample. The highest strength growth was related to the TP-D sample, which experienced a 58% increase in tensile strength compared to the CF sample. The tensile strength efficiency of this sample is 89.3% compared to the base metal. The highest increase in ductility was related to the TP-D sample, which experienced a 35% increase in ductility compared to the CF sample. The ductility efficiency of this sample is 81.1% compared to the base metal. پرونده مقاله

The present study investigated the effect of using tools with tapered pins in Friction Stir Welding (FSW) of AA6061-T6 aluminum alloy. Two techniques named conventional FSW and Refill Friction Stir Welding (RFSW) were used for this purpose. Five tools with different tapered angles (0, 5, 10, 15, and 20 degrees) were used. To study the mechanical properties, tensile, three-point bending, and Vickers microhardness tests were performed. Macrographic and microstructural tests were also used to investigate the metallurgical properties of the welded samples. Based on the results, it was found that the key factors determining the ductility and strength of the welded specimens are the type of welding process (conventional FSW or RFSW) and the geometry of the tool pin (straight or tapered pin). Furthermore, it was found that all specimens welded by RFSW have higher tensile strength and elongation than the samples welded by conventional FSW. پرونده مقاله