Tarbiat Modares University Modares Mechanical Engineering 2476-6909 26 10 2026 09 23 The Simultaneous Effect of Impact Modifier and Calcium Carbonate on UPVC Profile Mechanical Properties The Simultaneous Effect of Impact Modifier and Calcium Carbonate on UPVC Profile Mechanical Properties 757 768 28445 10.48311/mme.2026.119370.82981 FA Negin Moallemi Khiavi R&D Manager, Roozwin Industrial Complex, Ardadil,, Iran 0009-0007-1390-7612 Ata Tavakkoli Aval Managing Director, Roozwin Industrial Complex, Ardabil, Iran Journal Article 2026 02 18 This research experimentally evaluated the mechanical performance of UPVC door and window profiles produced using three industrial formulations designated TF-01, TF-02, and TF-03, which contain varying amounts of "ACR" and "CPE" impact modifiers, as well as Calcium Carbonate (〖"CaCO" 〗_3). A comprehensive series of standard tests, including flexural modulus, tensile impact strength, material and profile Charpy impact strength, falling-weight impact test, and compression and tensile stress tests on welded corner joints, were conducted in accordance with the Iranian National Standard INSO 12291-1 and corresponding international standards, at the Plastics Technology Institute of the Roozwin Industrial Complex. The results clearly demonstrate that the TF-03 formulation, characterized by the optimized balance of "ACR" and a reduced 〖"CaCO" 〗_3content from “36Phr” (in TF-01) to “29Phr”, yielded significant performance improvements. Specifically, TF-03 achieved a maximum tensile impact strength of “683 kJ/m2”, substantially higher than the “297 kJ/m2” recorded for TF-01. Furthermore, its profile Charpy impact strength reached “51 kJ/m2”, surpassing the minimum standard requirement (≥〖"\"45 kJ/m" 〗^2"), while TF-01 only reached “30.8 kJ/m2 kJ/m2”. Additionally, the falling-weight impact tests indicated that all three formulations exhibited satisfactory performance (zero failures in ten applied impacts). It can be stated that the reduction of Calcium Carbonate concentration to “29Phr”, by mitigating stress concentration, was a key factor enabling TF-03 to attain the highest toughness and achieve full compliance with the standard’s impact requirements. This research experimentally evaluated the mechanical performance of UPVC door and window profiles produced using three industrial formulations designated TF-01, TF-02, and TF-03, which contain varying amounts of "ACR" and "CPE" impact modifiers, as well as Calcium Carbonate (〖"CaCO" 〗_3). A comprehensive series of standard tests, including flexural modulus, tensile impact strength, material and profile Charpy impact strength, falling-weight impact test, and compression and tensile stress tests on welded corner joints, were conducted in accordance with the Iranian National Standard INSO 12291-1 and corresponding international standards, at the Plastics Technology Institute of the Roozwin Industrial Complex. The results clearly demonstrate that the TF-03 formulation, characterized by the optimized balance of "ACR" and a reduced 〖"CaCO" 〗_3content from “36Phr” (in TF-01) to “29Phr”, yielded significant performance improvements. Specifically, TF-03 achieved a maximum tensile impact strength of “683 kJ/m2”, substantially higher than the “297 kJ/m2” recorded for TF-01. Furthermore, its profile Charpy impact strength reached “51 kJ/m2”, surpassing the minimum standard requirement (≥〖"\"45 kJ/m" 〗^2"), while TF-01 only reached “30.8 kJ/m2 kJ/m2”. Additionally, the falling-weight impact tests indicated that all three formulations exhibited satisfactory performance (zero failures in ten applied impacts). It can be stated that the reduction of Calcium Carbonate concentration to “29Phr”, by mitigating stress concentration, was a key factor enabling TF-03 to attain the highest toughness and achieve full compliance with the standard’s impact requirements.

https://mme.modares.ac.ir/article_28445_4eedf3f92629bc3b1a208cfaacc4b2d2.pdf

Tarbiat Modares University Modares Mechanical Engineering 2476-6909 26 10 2026 09 23 Design and Optimization of a Pendulum Driven Piezoelectric Energy Harvester Embedded in Wheel Spokes for Autonomous Tire Sensor Systems Design and Optimization of a Pendulum Driven Piezoelectric Energy Harvester Embedded in Wheel Spokes for Autonomous Tire Sensor Systems 769 779 28771 10.48311/mme.2026.119397.82983 FA Javad Farjadi Bajestani Department of Mechanical Engineering, Ferdowsi University of Mashhad, Mashhad, Iran Mohammad Hossein Abolbashari Department of Mechanical Engineering, Ferdowsi University of Mashhad, Mashhad, Iran 0000-0001-6703-6364 Journal Article 2026 02 18 Energy harvesting technologies aim to recover wasted mechanical energy and are typically categorized into piezoelectric, electromagnetic, and electrostatic mechanisms. Among these, piezoelectric harvesters are particularly appealing due to their structural simplicity, scalability, and high energy density. This study presents a novel vibration-based piezoelectric energy harvesting system integrated within the spokes of a vehicle wheel to continuously supply power for autonomous tire sensor systems. The design employs a pendulum embedded inside each spoke that oscillates during wheel rotation and impacts plates on both sides, thereby exciting the piezoelectric layers mounted on them and converting vibrational energy into electrical output. Eliminating the use of adhesives and the placement of piezoelectric plates significantly improve structural integrity, durability, and operational safety compared to conventional strain based configurations mounted on the tire’s inner liner. The governing equations were solved and the results were validated against finite element analysis performed in COMSOL Multiphysics. The proposed configuration achieves average output power levels exceeding those of previously reported wheel-based designs by factors ranging from 2 to 20,000 while maintaining stable performance within the 20–120 km/h speed range required for Tire Pressure Monitoring System applications. Genetic algorithm–based optimization further enhanced the performance by 82.27%, confirming the system’s feasibility for next-generation intelligent tire technologies. Energy harvesting technologies aim to recover wasted mechanical energy and are typically categorized into piezoelectric, electromagnetic, and electrostatic mechanisms. Among these, piezoelectric harvesters are particularly appealing due to their structural simplicity, scalability, and high energy density. This study presents a novel vibration-based piezoelectric energy harvesting system integrated within the spokes of a vehicle wheel to continuously supply power for autonomous tire sensor systems. The design employs a pendulum embedded inside each spoke that oscillates during wheel rotation and impacts plates on both sides, thereby exciting the piezoelectric layers mounted on them and converting vibrational energy into electrical output. Eliminating the use of adhesives and the placement of piezoelectric plates significantly improve structural integrity, durability, and operational safety compared to conventional strain based configurations mounted on the tire’s inner liner. The governing equations were solved and the results were validated against finite element analysis performed in COMSOL Multiphysics. The proposed configuration achieves average output power levels exceeding those of previously reported wheel-based designs by factors ranging from 2 to 20,000 while maintaining stable performance within the 20–120 km/h speed range required for Tire Pressure Monitoring System applications. Genetic algorithm–based optimization further enhanced the performance by 82.27%, confirming the system’s feasibility for next-generation intelligent tire technologies.

https://mme.modares.ac.ir/article_28771_97f415c3bb3fe916c116c41d3746cc73.pdf

Tarbiat Modares University Modares Mechanical Engineering 2476-6909 26 10 2026 09 23 Sensitivity Analysis of the Influential Parameters on the Geometric Properties of Laser Cladding on a Hastelloy X Superalloy Substrate Using NiCoCrAlY Powder Sensitivity Analysis of the Influential Parameters on the Geometric Properties of Laser Cladding on a Hastelloy X Superalloy Substrate Using NiCoCrAlY Powder 781 794 28742 10.48311/mme.2026.119664.82990 FA Amin Alimohammadi Faculty of Mechanical Engineering, Faculty of Engineering, University of Tehran. Alireza Araee Faculty of Mechanical Engineering, Faculty of Engineering, University of Tehran. Journal Article 2026 03 20 NiCoCrAlY coatings are widely used in aerospace industries and gas turbines due to their exceptional resistance to high-temperature oxidation and corrosion. Despite this significance, the quantitative analysis of the influence of laser cladding process parameters on the geometrical characteristics of these coatings, particularly using sensitivity analysis methods, remains a research gap. In this study, the effects of laser power, duty cycle, and scanning speed on the coating height, width, angle, and dilution produced by laser cladding were investigated. For this purpose, a fiber laser with a maximum power of 1 kW was utilized. RSM developed regression models, and ANOVA confirmed that the models were significant, with a high R² and a non-significant lack of fit. The results of Sobel sensitivity analysis revealed that scanning speed has a dominant effect on height, angle, and dilution, contributing more than 80% (88.8%, 80.7%, and 81.8%, respectively). In contrast, laser power exhibited a minor to moderate influence (3.9%, 16.3%, and 13.3%, respectively), while the duty cycle, with contributions of 7.3%, 3%, and 4.9%, was the least significant control parameter for these three output responses. For coating width, laser power (51.3%) was more than twice as influential as duty cycle (25.8%) or scanning speed (22.9%). The complete consistency in the ranking of effective factors between the Sobel method and RSM confirms the validity of the results. This study demonstrates that Sobel sensitivity analysis, by quantitatively decomposing the contribution of each parameter, serves as a powerful tool for the optimal design of the laser cladding process. NiCoCrAlY coatings are widely used in aerospace industries and gas turbines due to their exceptional resistance to high-temperature oxidation and corrosion. Despite this significance, the quantitative analysis of the influence of laser cladding process parameters on the geometrical characteristics of these coatings, particularly using sensitivity analysis methods, remains a research gap. In this study, the effects of laser power, duty cycle, and scanning speed on the coating height, width, angle, and dilution produced by laser cladding were investigated. For this purpose, a fiber laser with a maximum power of 1 kW was utilized. RSM developed regression models, and ANOVA confirmed that the models were significant, with a high R² and a non-significant lack of fit. The results of Sobel sensitivity analysis revealed that scanning speed has a dominant effect on height, angle, and dilution, contributing more than 80% (88.8%, 80.7%, and 81.8%, respectively). In contrast, laser power exhibited a minor to moderate influence (3.9%, 16.3%, and 13.3%, respectively), while the duty cycle, with contributions of 7.3%, 3%, and 4.9%, was the least significant control parameter for these three output responses. For coating width, laser power (51.3%) was more than twice as influential as duty cycle (25.8%) or scanning speed (22.9%). The complete consistency in the ranking of effective factors between the Sobel method and RSM confirms the validity of the results. This study demonstrates that Sobel sensitivity analysis, by quantitatively decomposing the contribution of each parameter, serves as a powerful tool for the optimal design of the laser cladding process.

https://mme.modares.ac.ir/article_28742_9828cb4d004ea22ddad5fb03c84a2379.pdf

Tarbiat Modares University Modares Mechanical Engineering 2476-6909 26 10 2026 09 23 Chromosome-Based Mapping of the Obstacle Traversal Problem: An Adaptive Fuzzy-Genetic Framework for a Six Wheel-Leg Robot Chromosome-Based Mapping of the Obstacle Traversal Problem: An Adaptive Fuzzy-Genetic Framework for a Six Wheel-Leg Robot 795 815 28900 10.48311/mme.2026.120505.83013 FA Seyed Mostafa Hoseini Department of Mechanical Engineering, Isfahan University of Technology, Isfahan, Iran 0009-0008-2623-4397 Saeed Behbahani Department of Mechanical Engineering, Isfahan University of Technology, Isfahan, Iran 0009-0009-7178-4168 Journal Article 2026 05 17 Hybrid wheeled-legged robots offer superior mobility in unstructured terrain by combining the locomotion efficiency of wheels with the adaptability of legs. However, efficiently traversing complex obstacles necessitates intelligent reconfiguration policies that coordinate leg movements, wheel velocities, and body posture. This paper presents an integrated learning framework to derive optimal policies for a six-wheeled-legged robot traversing an asymmetric step obstacle. Initially, the kinematic relationships governing wheel-leg interaction with the ground and slip-free wheel velocity coordination are formulated. As the key innovation, the obstacle traversal problem is mapped into a low-dimensional and continuous parametric optimization space, upon which a Genetic Algorithm-based learning framework is developed. Without imposing restrictive assumptions, this framework significantly reduces the complexity of the search space. In addition, fuzzy logic is employed to integrate human expertise into the cost function and adapt its weighting coefficients. This facilitates the automatic discovery of practical policies without relying on pre-defined motion sequences. Simulation results are validated through experiments on the ViraHex robot, demonstrating close agreement in leg motion sequences, support polygon transitions, and the mitigation of undesired body deviations. Overall, this framework offers an effective and scalable solution for optimizing obstacle traversal in hybrid robots, highlighting the potential of learning-based strategies in complex environments. Hybrid wheeled-legged robots offer superior mobility in unstructured terrain by combining the locomotion efficiency of wheels with the adaptability of legs. However, efficiently traversing complex obstacles necessitates intelligent reconfiguration policies that coordinate leg movements, wheel velocities, and body posture. This paper presents an integrated learning framework to derive optimal policies for a six-wheeled-legged robot traversing an asymmetric step obstacle. Initially, the kinematic relationships governing wheel-leg interaction with the ground and slip-free wheel velocity coordination are formulated. As the key innovation, the obstacle traversal problem is mapped into a low-dimensional and continuous parametric optimization space, upon which a Genetic Algorithm-based learning framework is developed. Without imposing restrictive assumptions, this framework significantly reduces the complexity of the search space. In addition, fuzzy logic is employed to integrate human expertise into the cost function and adapt its weighting coefficients. This facilitates the automatic discovery of practical policies without relying on pre-defined motion sequences. Simulation results are validated through experiments on the ViraHex robot, demonstrating close agreement in leg motion sequences, support polygon transitions, and the mitigation of undesired body deviations. Overall, this framework offers an effective and scalable solution for optimizing obstacle traversal in hybrid robots, highlighting the potential of learning-based strategies in complex environments.

https://mme.modares.ac.ir/article_28900_f29fa72991dafa0ab83a053e89b9866a.pdf

Tarbiat Modares University Modares Mechanical Engineering 2476-6909 26 10 2026 09 23 Numerical Study of the Aerodynamic Performance of a Light Aircraft Propeller Equipped with Surface Suction Slot Numerical Study of the Aerodynamic Performance of a Light Aircraft Propeller Equipped with Surface Suction Slot 817 830 28888 10.48311/mme.2026.118933.82963 FA HamidReza Jashnani Tarbiat Modares univercity Saeed Karimian Aliabadi Tarbiat Modares university 0000-0003-4782-2813 Journal Article 2026 04 26 In this study, the aerodynamic performance of the Bonanza light aircraft propeller was investigated by implementing a suction slot on the blade airfoil surface. Previous research has predominantly investigated the use of surface suction slots for delaying flow separation and increasing stall speed on aircraft wings, compressor blades, wind turbines, and UAV propellers. Such slots are generally categorized into two types: active and passive. In the present work, a passive configuration was adopted to prevent additional structural weight and avoid any alteration in the aircraft’s center of gravity during flight. The position of the suction slot on the lower surface of a two-dimensional asymmetric airfoil was determined relative to the leading edge, taking into account the geometric pitch angle at cruise altitude and velocity, as well as the temperature, pressure, and humidity conditions representative of Tehran Mehrabad International Airport. Baseline calculations for a propeller without a slot were carried out using Blade Element Momentum (BEM) theory, complemented by numerical simulations in ANSYS Fluent 2025 R1. The findings indicated that the closer the slot is positioned to the leading edge, the smaller its effect on reducing the lift coefficient. Nevertheless, when the slot was applied according to the geometric dimensions proposed in this study, the lift coefficient (CL) of the propeller blade increased by about 7%, the moment coefficient (Cm) at the reference station increased by about 6%, and the overall propeller efficiency (η) improved by approximately 4% within the advance ratio range. In this study, the aerodynamic performance of the Bonanza light aircraft propeller was investigated by implementing a suction slot on the blade airfoil surface. Previous research has predominantly investigated the use of surface suction slots for delaying flow separation and increasing stall speed on aircraft wings, compressor blades, wind turbines, and UAV propellers. Such slots are generally categorized into two types: active and passive. In the present work, a passive configuration was adopted to prevent additional structural weight and avoid any alteration in the aircraft’s center of gravity during flight. The position of the suction slot on the lower surface of a two-dimensional asymmetric airfoil was determined relative to the leading edge, taking into account the geometric pitch angle at cruise altitude and velocity, as well as the temperature, pressure, and humidity conditions representative of Tehran Mehrabad International Airport. Baseline calculations for a propeller without a slot were carried out using Blade Element Momentum (BEM) theory, complemented by numerical simulations in ANSYS Fluent 2025 R1. The findings indicated that the closer the slot is positioned to the leading edge, the smaller its effect on reducing the lift coefficient. Nevertheless, when the slot was applied according to the geometric dimensions proposed in this study, the lift coefficient (CL) of the propeller blade increased by about 7%, the moment coefficient (Cm) at the reference station increased by about 6%, and the overall propeller efficiency (η) improved by approximately 4% within the advance ratio range.

https://mme.modares.ac.ir/article_28888_6cd4d4f7768fc86ca5642be0f600b518.pdf

Tarbiat Modares University Modares Mechanical Engineering 2476-6909 26 10 2026 09 23 Investigation of friction coefficient and convective heat transfer in a metal foam-filled porous tube based on a two-equation model Investigation of friction coefficient and convective heat transfer in a metal foam-filled porous tube based on a two-equation model 831 840 28744 10.48311/mme.2026.118915.82961 FA Meysam Mahmoudi Mechanical Engineering Department, Velayat University, Iranshahr, Iran Journal Article 2026 01 28 In this study, a closed-form analytical solution is presented for fully developed forced convection in a cylindrical tube partially filled with open-cell metal foam. The flow field is modeled using the Brinkman–Darcy approach, while heat transfer between the solid and fluid phases is analyzed based on the local thermal non-equilibrium (LTNE) model. Compared with the local thermal equilibrium (LTE) assumption, LTNE provides more accurate predictions, particularly when the solid-to-fluid thermal conductivity ratio is high. The validity of the model is confirmed through comparison with two limiting cases: a hollow tube and a fully filled tube. Owing to the closed-form nature of the solution, system performance can be evaluated continuously over the entire porosity range of (0,1). The results show that, as the dimensionless interfacial radius increases, the friction factor decreases and varies inversely with the Reynolds number. The Nusselt number exhibits a non-uniform dependence on porosity, and for each pore density there exists an optimal porosity that maximizes heat transfer; for ω=30 PPI, this optimum is obtained at ε=0.87. In addition, the dependence of Nu on the interfacial radius is nonlinear, and in some ranges the thermal performance becomes even weaker than that of the hollow tube. Overall, the findings indicate that a partially filled configuration, with proper selection of geometric and morphological parameters, can achieve an effective balance between heat transfer enhancement and pressure-drop control. In this study, a closed-form analytical solution is presented for fully developed forced convection in a cylindrical tube partially filled with open-cell metal foam. The flow field is modeled using the Brinkman–Darcy approach, while heat transfer between the solid and fluid phases is analyzed based on the local thermal non-equilibrium (LTNE) model. Compared with the local thermal equilibrium (LTE) assumption, LTNE provides more accurate predictions, particularly when the solid-to-fluid thermal conductivity ratio is high. The validity of the model is confirmed through comparison with two limiting cases: a hollow tube and a fully filled tube. Owing to the closed-form nature of the solution, system performance can be evaluated continuously over the entire porosity range of (0,1). The results show that, as the dimensionless interfacial radius increases, the friction factor decreases and varies inversely with the Reynolds number. The Nusselt number exhibits a non-uniform dependence on porosity, and for each pore density there exists an optimal porosity that maximizes heat transfer; for ω=30 PPI, this optimum is obtained at ε=0.87. In addition, the dependence of Nu on the interfacial radius is nonlinear, and in some ranges the thermal performance becomes even weaker than that of the hollow tube. Overall, the findings indicate that a partially filled configuration, with proper selection of geometric and morphological parameters, can achieve an effective balance between heat transfer enhancement and pressure-drop control.

https://mme.modares.ac.ir/article_28744_7b75a9a9404959d96c63d1f61ec75550.pdf