https://jmee.isme.ir/ Iranian Journal of Mechanical Engineering Transactions of the ISME en daily 1 Mon, 01 Sep 2025 00:00:00 +0330 Mon, 01 Sep 2025 00:00:00 +0330 https://jmee.isme.ir/article_723291.html This article presents a novel application of deep learning in automated fruit-sorting robotics, improving real-time object recognition and handling. By integrating advanced neural networks, the robot achieves higher accuracy in identifying various fruits, addressing fruit variability and enhancing sorting precision. This innovation, combining deep learning and visual servoing, represents a significant advancement in automated fruit-sorting technology, with promising benefits for agricultural processes. The project aims to control a fruit-sorting robot using image processing data, merging sliding mode control and NN-based (neural network-based) techniques for automation. Utilizing the latest YOLO (You Only Look Once) model, the system classifies and positions fruits rapidly and accurately, making it suitable for real-time applications. After identifying fruit types and positions, a controller is designed for the pick-and-place process. Sliding mode control manages uncertainties and guides manipulator movements precisely, while a neural network controls joint angles for smooth and accurate fruit manipulation. Comparative tests on a simulated robot revealed that the NN-based controller excels in accuracy and speed, adapting to different fruit configurations effectively. The sliding mode controller, though robust and stable, is sensitive to uncertainties, affecting sorting precision. The hybrid system, integrating both controllers, enhances adaptability by combining the NN-based approach's precision with the stability of sliding mode control, optimizing fruit-sorting performance across diverse scenarios. Results emphasize selecting the appropriate controller to balance precision and speed based on specific application needs. https://jmee.isme.ir/article_718880.html In this paper, the dynamic stress intensity factors (DSIFs) in an orthotropic strip coated by a functionally graded piezoelectric (FGP) containi8ng several moving cracks has been studied. The distributed dislocation method (DDM) is extended to construct integral equations for the several cracks. At first, the stress fields in an orthotropic strip coated by FGP containing a single dislocation are calculated. Then, by use of distributed dislocation density on the faces of cracks, systems of singular integral equations with Cauchy type singularity are obtained. Finally, the integral equations are solved with an appropriate numerical method to specify the dislocation density and then DSIFs at the crack tips. The primary objective of this paper is to investigate the effects types of loading, the position of cracks relative to each other, crack speed and nonhomogeneity parameter on the DSIFs. https://jmee.isme.ir/article_719349.html Fused deposition modeling (FDM) is the most popular, simplest, and least expensive method of additive manufacturing and 3D printing. This technique, based on extruding molten thermoplastic filament, is favored across industries for rapid prototyping and creating complex geometries without molds or extra equipment. A key challenge in FDM is the significant impact of printing parameters on the mechanical and physical properties of the final product. This research aims to examine how basic printing parameters, specifically using a 0.4 mm nozzle diameter in two injection mold patterns (linear and concentric), affect tensile strength. Results showed that altering the injection pattern changes tensile strength, ranging from 28.1 MPa to 27.8 MPa at 190℃. The linear pattern achieved the highest tensile strength, while the concentric pattern had the lowest. Additionally, scanning electron microscope images of the fracture surfaces revealed that all samples had micro holes at the layer interfaces, a characteristic inherent to the FDM process. https://jmee.isme.ir/article_719903.html Passive dynamic walkers have gained widespread interest for their ability to mimic human-like movements. However, modeling and simulating these walkers in mathematical software can be challenging due to their complex dynamic equations of motions. This paper presents a framework for multibody modeling and simulating passive dynamic biped walkers with rigid legs in MSC ADAMS. This approach significantly simplifies the modeling process by avoiding the complexity of deriving mathematical equations of motion. The framework involves creating a general base model of the biped walker (such as a compass-like design), followed by dynamic analysis in MSC ADAMS. The model developed in MSC ADAMS is carefully adapted through a suggested parameter adjustment procedure to ensure that the core functionalities of a purely mathematical model are preserved. The findings indicate that a slightly higher initial angular velocity of the stance leg is required in MSC ADAMS compared to the mathematical model to achieve stable periodic motion and account for stance foot slippage. This research enables more realistic simulations of passive biped robots in MSC ADAMS, reducing reliance on purely theoretical models. https://jmee.isme.ir/article_719421.html This research investigated how atmospheric humidity affects both steady-state and transient performance metrics of a trainer single-spool turbojet engine. Using the inter-component volume (ICV) method, a detailed thermodynamic model was developed and simulations were conducted in MATLAB/Simulink. The study considered modifications to gas properties due to water vapor content. Notably, compressor fouling exacerbates performance degradation, especially when combined with varying ambient humidity levels. Findings indicate that without fouling, peak humidity has minimal impact (within 1% variation). However, fouling at zero relative moisture reduces thrust by 3.48% and increases specific fuel consumption by 1.64%. Under saturated humid conditions (100% relative humidity), thrust can decrease by up to 7%, and fuel consumption rises by approximately 5%. Additionally, transient response times suffer due to both fouling and increased humidity. https://jmee.isme.ir/article_719929.html This paper investigates and compares the coordinated landing of multiple vehicles using the Rough Mimetic Neural Controller (R-MNC) and Sliding Mode Controller. Coordinated landing scenarios, critical for advanced aerospace operations, require robust control strategies to handle nonlinear dynamics and ensure safe, precise landings. In the simulations, nonlinear dynamic equations of the agents are used, and control signals are allocated among system actuators based on inputs such as gamma angle, angle of attack, and altitude rate. The NSGA-II optimization algorithm tunes controller parameters to enhance performance and reduce control effort. Results demonstrate that both controllers effectively stabilize the vehicle and achieve desired outcomes, but R-MNC shows superior adaptability in dynamic environments, particularly under varying conditions. This study examines the trade-offs and complementary advantages of both methods, offering insights for designing reliable coordinated landing strategies in complex aerospace missions. https://jmee.isme.ir/article_725985.html This paper provides an analytical approach to determining the buckling load of an axisymmetric cylindrical shell made of functionally graded material (FGM) using utilizing the first-order shear deformation theory (FSDT) and von Karman relations. Nonlinear equilibrium equations are derived using the virtual work principle and solved with the perturbation technique. The stability equations are then obtained using the adjacent criterion method, resulting in a system of coupled linear differential equations with variable coefficients, which are solved analytically for the buckling load. A parametric study examines how various geometric and material properties influence the results. It is found that transitioning from homogeneous materials to FGMs increases the buckling load by 4–11%, depending on the shell dimensions. Additionally, finite element method (FEM) results are used to validate the analytical findings and are compared with existing literature. https://jmee.isme.ir/article_728136.html This study presents a detailed numerical analysis of composite beams enhanced with piezoelectric actuators, focusing on their mechanical performance under varying design parameters. Finite Element Analysis (FEA) using Abaqus software was employed to investigate the influence of fiber orientation angles (0° to 90°) and the number of layers (2 to 6) on the stress-strain behavior and bending resistance of the beams. The results demonstrate that optimal fiber orientation and appropriate layer configurations significantly enhance mechanical performance, with notable improvements in maximum stress capacity and strain energy absorption. The findings validate the potential of smart composite systems in advanced precision engineering applications and provide critical insights for optimizing their structural performance through parametric design adjustments.This study also offers a comparative analysis with Classical Laminate Theory to identify deviations resulting from shear deformation and coupling effects. These results hold promise for applications in aerospace, robotics, and energy systems, where adaptability and structural resilience are essential. https://jmee.isme.ir/article_713959.html Heat exchangers constitute the most important components of many industrial processes with a wide range of engineering applications. Numerous research works are going on to enhance thermal performance of the heat exchangers by adopting different heat transfer enhancement techniques with additional requirements of energy saving, size reduction and minimal operation cost. These methods may be active methods, which require an external power or passive methods, which employ special surface geometries or additives to the fluids. To overcome the disadvantages and to improve quantity of productivity per time, straight tube or helical tube can be inserted in double tube heat exchangers termed as triple fluid heat exchanger or triple concentric tube heat exchanger. TFHE is one of the examples of such heat exchangers, where a straight tube is inserted between two concentric straight tubes with several applications found in aerospace, petrochemical, food processing industries, purification and liquefactions of hydrogen, air separation systems etc. In this review article, flow configurations, arrangements of tubes, using phase change materials and enhancement of effectiveness of the three fluid heat exchanger has been discussed. https://jmee.isme.ir/article_724916.html In this article, the axial crushing behavior of energy absorbers is analyzed. Numerical analysis compares absorbers with various cross-sections such as circular, square, hexagonal, conical, and square frustum under impact loading, using ABAQUS software. The effect of velocity on proportions such as the type of deformation during impact, energy absorption density, and maximum collision strength values have been investigated. This study identifies and interprets the variations and parameters affecting the adsorbent efficiency. Additionally, the initial peak force of the conical section was significantly reduced, achieving 21% higher specific energy absorption compared to other designs. This study also focuses on dynamic energy absorbers for Formula Student competitions, aiming to improve their efficiency. The addition of grooves and holes increased the efficiency of the crushing force (η) by 38% and significantly enhanced the energy absorption per unit mass known as specific energy absorption (SEA) is also presented, which is an innovation not previously explored. By reducing the initial maximum force, increasing the crushing length, and incorporating symmetric folding, a new model was developed, enhancing both energy absorption capacity and overall efficiency. https://jmee.isme.ir/article_727597.html This paper analyzes the thermoelasticity of the thick-walled cylindrical shell under pressure and thermal loading on the inner surface of the shell. First-order shear deformation and First-order temperature theories are used to determine the displacement and temperature fields, respectively, which include displacement and temperature changes along the length and thickness of the shell. The system's governing equations and boundary conditions have been derived utilizing the energy method. The system of governing differential equations was solved using the analytical process of matched asymptotic method of perturbations technique. The mechanical and temperature behavior of the cylindrical shell has been analyzed by solving the equations and obtaining the displacement and temperature parameters. The analytical solution was then compared with the numerical solution, showing a substantial similarity in behavior. Moreover, the effectiveness of the proposed method in addressing axisymmetric cylindrical shells under various boundary conditions and thermo-mechanical loading is demonstrated. Examining the shell's mechanical and thermal behavior reveals that shear stress changes significantly near the boundaries, and both displacement and temperature fields are influenced by the cylindrical shell's length. https://jmee.isme.ir/article_728240.html In the present study, enhancing the performance of a transcritical refrigeration system is investigated. To do this, an ORC is employed to recover the waste energy of the compressor outlet stream. Moreover, the power of the ORC is used to operate a vapor compression refrigeration cycle which is used for subcooling the exit vapor of the gas cooler. Furthermore, an expander is used to produce more power. Thermodynamic modeling shows that application of ORC, Subcooling system and expander for evaporator temperature of -20°C and gas cooler temperature of 40 °C leads to an enhancement of 65.83% and 63.9% in COP and exergy efficiency, respectively. Moreover, the exgergy analysis indicates that in the presented cycles the compressor, the cascade heat exchanger the evaporator and the expansion valve have the maximum exergy destruction rates. The effect of gas cooler temperature, gas cooler pressure, evaporator temperature and ORC turbine inlet temperature on the cycle performance is also investigated.