The mechanization-oriented technology for shallot planting is a suitable solution which has a positive impact on changing the style of farming and reducing labor costs and increasing the efficiency in the process of planting shallot. In this research using an automatic planting device, the kinematics of shallot seed feed roller is calculated, designed and surveyed for correct positioning of the shallot in the created hole. This is done by the aid of Autodesk Inventor Professional and Matlab Simulink software. Working principle Diagram of planting shallot device is presented and the design parameters were optimized, and the stability of the suspension system used in the device was investigated.

Nowadays, in order to increase construction of tall structures, the importance of choosing optimum systems, with a huge energy absorption capacity against wind and earthquake loads, has been widely considered. Since four decades ago, steel shear walls had been used as a stiff and high performance lateral system. This study is about the effect of concrete filled steel tubes (CFT) columns as vertical boundary elements of steel shear wall on seismic behavior of steel structures. Due to do this, three 10-storey steel structures, with similar plans and lateral load career systems of steel shear wall, coinciding X-bracing, and moderate steel frame were analyzed by means of non-linear, time-history method through SAP2000 software, and the results of roof displacement of them were compared with each other. Also after validating a two-storey, single-span frame sample with steel shear walls and CFT columns, 3 single-storey structures were analyzed by means of hysteresis and pushover, through ABAQUS software. The results of this study showed that a shear wall system presents suitable stiffness, resistance and ductility in comparison with other lateral bearing systems.

Friction Stir Welding (FSW) is a process of welding materials that generates heat through friction. Plastic deformation, nonlinear material movement, tool-to-structural evolution friction, and heat production from friction and plastic deformation all have an impact on FSW operation. In this paper, thermo-mechanical characteristics of aluminum alloy AA6061-T6 during the FSW process were simulated based on COMSOL® software using a finite element approach. A conceptual model was created to interpret the thermal and structural analyses. According to the obtained results, the temperature rises on the top and bottom surfaces as the axial force increases but decreases along the line perpendicular to the weld direction. The overall temperature decreases as the forward welding speed rises within the acceptable induced temperature range of the workpiece, while the axial force and rotational speeds stay stable.

The article deals with stress separation using different experimental techniques and their comparison to numerical and theoretical solutions. The method is applied to a keyhole sample coupon, to which measurements of fringe order, temperature or displacement were made using photo-elasticity, TSA (Thermo-elastic Stress Analysis) and DIC (Digital Image Correlation). The results are compared to FEM simulations (Finite Element Method) using the stress concentration factor (Kt) as a benchmark. Additionally, an Airy stress function is proposed and tested against obtained measurements. The comparison of Kt shows agreement among measurements as well as numerical and theoretical results. It is concluded that the presented method can be used for isotropic materials subjected to the plane stress, where stress variation through-thickness is negligible.

Stainless steel (SS) and Titanium alloy (Ti) are the most commonly used materials in many industrial fields such as the automotive and aerospace industry. Stainless steel has good corrosion resistance and titanium alloy has an extremely lightweight characteristic. The combination of both materials has become a tremendous innovation in the industrial sector. Resistance spot welding which has commonly applied in many industrial fields is a good consideration to join these two dissimilar materials due to the high efficiency that could be achieved by using this method. However, the way of joining these dissimilar materials should be carefully considered due to the significant difference in mechanical properties between SS and Ti. In the present study, 3 mm of SS316L and Ti6Al4V sheets were joint under the resistance spot welding method with an aluminum interlayer. The optimized welding parameters were provided under the Taguchi method L9 orthogonal array along with the mechanical properties’ investigation. The optimum welding parameters were 11 kA of weld current, 30 Cycles of welding time, and 5 kN of electrode force which produced 8.83 kN tensile-shear load of the joint. The mechanical structure analysis shows the different morphology between stainless steel and titanium interfaces and the intermetallic compound layer was formed on the SS/Al and Al/Ti interfaces. The EDX analysis shows the atomic diffusion-reaction on the application of aluminum as an interlayer on the SS/Ti joint.

Rotating shafts have a vast application in various industries especially in the aerospace industry such as engines, compressors and turbines. The researchers have performed considerable efforts on the rotating shafts’ dynamic behavior because of their sensitivity to the rotor specifications and different parameters such as supports. In this paper by employing a pipe elbow element, an especial finite element formulation is derived to investigate dynamic behavior of rotating shaft in the presence of support clearance. The proposed element consists of four nodes with twenty-four degrees of freedom, which also accounts for the shear and gyroscopic effects. Within a finite element analysis framework, the focus of the paper is proposing a formulation to account for the dynamic behavior of a rotating shaft with much less number of elements. The element is implemented in a finite element code and then is used to model and analyze some rotating shaft examples. In order to verify the developed formulation, results are compared with those obtained from other schemes reported in the literature.

The blade shape parameters have a remarkable effect on the centrifugal pump performance. In order to reveal the relationship between these parameters and pump performance, a single channel was regarded as the research object to calculate its performance by numerical simulation, and the performance was measured on an experimental rig. The optimized ANN is proposed, and it is proved to be highly accurate. The ANN correlation coefficient of the total response could be above 0.997 after thousands of retaining. The sorts and degrees affecting performance parameters were found out by gray relation analysis. It was found that the blade angles at the leading edge were more influential for reaction force, head and minimum pressure, while the wrap angles had greater impact for efficiency. Furthermore, a multiple linear regression model was established to quantify the weight and trend of the influence of blade shape parameters on performance. The results provide a reference guide for the optimized design of centrifugal impeller to improve pump performance.

The application of Fused Deposition Modeling (FDM) is restricted due to limited information about the mechanical properties of printed parts. Therefore, it is required to determine the mechanical properties of the FDM properties to avail the full benefit of the FDM process. In the present study, Classic Laminate Theory (CLT) has been employed at the different configurations of layer thickness and raster width. The required elastic constant of material for CLT has been experimentally obtained through FDM printed Polylactic Acid (PLA) unidirectional specimens at 0°, 45° and 90° for different combinations of layer height and raster width. For these different combinations of layer height and raster width, constitutive models were developed to predict the tensile properties of the PLA parts. Tensile strength of the FDM printed bi-directional specimens has been experimentally obtained to validate the proposed CLT model results. The experimental tensile strength data is in good agreement with the data predicted by the proposed CLT model. Higher tensile strength and modulus were achieved with 0° raster angle compared to 90° raster angle. In the case of a bi-directional printed specimen, higher tensile strength was obtained with 45°/-45° raster angle followed by 30°/-60° and 0°/90° raster angle.

A study of the stress-strain state (SSS) of disc specimens has been conducted when testing specimens with stress concentrators (grooves). The research has shown that the truncation of circular discs along two symmetrical chords makes it possible to change the type (the ratio of principal stresses) of SSS that occurs at the destruction site. Therefore, these specimens can be used to assess the structural strength of materials on standard single-drive testing machines, taking into account the real type of SSS that occurs in the bearing elements of machines. The results of numerical SSS modeling have been used to build the dependences of the SSS type and level on geometric parameters of specimens. Geometrical parameters can be chosen for a certain SSS type to assess both the static and fatigue strengths of materials used in the manufacture of bearing elements.

Large-scale wind turbines mostly use Continuously Variable Transmission (CVT) as the transmission system, which is highly efficient. However, it comes with high complexity and cost too. In contrast, the small-scale wind turbines that are available in the market offer a one-speed gearing system only where no gear ratios are varied, resulting in low efficiency of harvesting energy and leading to gears failure. In this research, an unsupervised machine-learning algorithm is proposed to address the energy efficiency of the automatic transmission system in vertical axis wind turbines (VAWT), to increase its efficiency in harvesting energy. The aim is to find the best adjustment for VAWT while the automatic transmission system is taken into account. For this purpose, the system is simulated and tested under various gear ratios conditions while a centrifugal clutch is applied to automatic gear shifting. The outcomes indicated that the automatic transmission system could successfully adjust the spinning in line with the wind speed. As a result, the obtained level of harvested voltage and power by VAWT with the automatic transmission system are improved significantly. Consequently, it is concluded that automatic VAWTs, equipped with the machine-learning capability can readjust themselves with the wind speed more efficiently.