Recent Patents on Mechanical Engineering - Volume 18, Issue 5, 2025

The present need for manufacturing industries is the creation of a new class of engineered materials with high specific properties. In this regard, nanocomposite materials have shown promising results compared to monolithic materials. Recent patents also show high mechanical and tribological properties.

The tribological and mechanical properties of graphene nanoplatelets (GNP)-reinforced aluminium 7075 nanocomposites are reported in this article with the objective of finding optimum properties.

The nanocomposites were successfully produced with the stir casting technique, a liquid metallurgy route with varying weight percentages of reinforcement composition of 0.5%, 1%, and 2%.

The result showed an improvement in ultimate tensile strength of 69.5% and microhardness of 76.67% in contrast to the base alloy when it was cast. The wear rate was dropped significantly by 43% and 40% in 10 N and 20 N loading conditions with respect to as-cast conditions. Further, a decrease in the average coefficient of friction was observed from 0.680 to 0.565.

Graphene nanoplatelets came out as excellent reinforcement in the aluminium 7075 alloy, as they showed an impact on improved properties. The decreasing wear rate and coefficient of friction showed their self-lubricating nature. Additionally, X-ray diffraction (XRD) results and optical microstructure were also discussed.

Owing to the promising characteristics— high strength-to-weight ratio, acoustic and thermal insulation, renewable and biodegradable, sisal fiber-based composites have been explored. Including patents, interesting literature is available on sisal fiber-based composites.

The materials under investigation were sisal fiber (SF), polypropylene (PP), and sisal- fiber-reinforced polypropylene composite (SFR-PC). Three different samples of SFR-PC were fabricated via injection molding. Their morphological-, mechanical-, thermal-, and water absorption- properties were analyzed.

The untreated sisal fiber (USF) sample showed a network microstructure with micro-void; however, the alkali (NaOH)-treated sisal fiber (TSF) sample envisages surface roughness morphology. The C-O stretching vibration of the acetyl groups of lignin in the USF vanished after the alkali treatment of SF. The degree of crystallinity index, thermal stability, weight loss, and water resistance improved with the alkali (NaOH) treatment of SF. The tensile modulus (E) for SFR- PC showed an increasing trend with the addition of TSF at all weights % envisaging a better interaction between polymer matrix and reinforcement; however, the 90PP-10TSF sample exhibited the highest storage modulus (Eˈ) at all temperatures due to the TSF distribution and agglomeration in the polymer matrix. The addition of TSF improved the loss modulus (E˝) for the SFR-PC sample as compared to the PP sample.

The 90PP-10TSF sample showed the optimum distribution of TSF in the PP matrix. DSC secondary heating thermograph depicted that the addition of TSF did not affect the melting temperature of SFR-PC samples, and the cooling thermograph showed that the addition of TSF in the polymer matrix gradually increased the crystallization temperature, suggesting a better packing of the cellulose chain. The 70PP-30TSF sample showed the highest absorption, followed by 80PP-20TSF and 90PP-10TSF samples, whereas the PP sample showed the lowest absorption.

This research aims to mitigate defects in the turning operation of thrust plates used in fighter jet fuel tank assemblies, thereby reducing the rejection rate and improving overall quality. This aligns with the aerospace industry's reliability goals.

The thrust plate is a critical component in fighter jet fuel tank assembly, transmitting engine thrust to the airframe. Quality compromises in this component can impair jet performance. It was observed that the thrust plate had a rejection rate of about 2.9% due to various defects. This real-world scenario underscores the importance of our study on the thrust plate and its potential impact on the aerospace industry. The rejection rate underscores its significance and potential for patent by quality improvement in turning of the thrust plate.

The objective is to mitigate turning operation defects on the thrust plate to reduce rejection rates, aligning with aerospace industry reliability goals.

Experimentation encompassed four pivotal factors: turning speed, feed rate, cutting depth, and tool inserts, implemented through Taguchi's Orthogonal Array technique. Grey Relational Analysis was utilized to optimize parameters in thrust plate turning. Specifically, this paper targeted the enhancement of its diameter, surface roughness, and tool life.

A single coefficient for the multiple responses, i.e., grey relational grade, has been determined, and optimum levels for the parameters have been identified. Confirmation experiments with the optimal factor level combination were carried out on a sample of thrust plates, and no rejections were observed.

An experimental design based on Taguchi’s orthogonal array approach was used to conduct the experiments. The Grey Relational Analysis has been applied to analyze the experimental results and optimize the turning operation process parameters for the responses thrust plate diameter, tool life, and surface roughness. With this, the rejection of the thrust plate has been considerably reduced.

The disposal of chicken eggshell (ES), a byproduct of aviculture, is a major environmental issue. Chicken eggshell can be utilized to create new low-cost, low-density consumer goods materials. In order to alleviate environmental difficulties, the proper usage of ES as a bio-waste should be actively pursued.

Composites emerged as the most promising materials in recent years. Nowadays, hybrid aluminium matrix composites were developed by utilizing of low-cost reinforcements with less density and high strength. Composite materials which were developed by use of agricultural waste as a reinforcement can be utilized in various applications/industries such as aeronautical, manufacturing, automobile etc.

The objective of present work is to find out the tribological characteristics of AA2024/SiC/carbonized eggshell hybrid green aluminium metal matrix composites (AMMCs). The wear rate (WR) and coefficient of friction (CF) were investigated at different combinations of load, reinforcement, sliding speed, and sliding distance.

A Taguchi-based L16 orthogonal array methodology was used to set up the combination of parameters. The mathematical models have been developed, and solved using non-dominating sorting genetic algorithm-II (NSGA-II). The solutions were predicted using NSGA-II were ranked using Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). The confirmation experiments were performed at three suggested settings (rank 1 to rank 3). In one of the patents (CN113957284B) the development method for hybrid composites is discussed.

The results revealed that hardness of AA2024 hybrid green composite was observed to be enhanced as compared to base aluminium alloy. Wear resistance of the AA2024/SiC/carbonized eggshell composite was also improved. The patents on Al composite (US 3649227) revealed that after the addition of reinforcement, the mechanical characteristics such as tensile strength was improved.

Wear resistance is improved on AA2024/SiC/carbonized eggshell composite. With an increase in reinforcement percentage and speed, the WR decreased from 29.16×10^-5 g/min to 26×10^-5 g/min. The CF increases from 0.4 to 0.46 with the increase in reinforcement percentage, from 3% to 12%.

Energy harvesting systems provide a sustainable way to capture and convert various forms of energy into usable electrical power. The Electromagnetic Energy Harvester (EMEH) systems function based on Faraday’s law and are usually implemented in small systems where the demand for electrical energy is low.

This study aims to expand the use of a pneumatic cylinder by enabling it to work as an EMEH.

The objective can be achieved by adding a coil arrangement wrapped around the pneumatic cylinder and taking advantage of the rectilinear motion of the cylinder's inner magnet, which is a moving magnetic field. The paper explored the influence of key parameters on the induced voltage through a series of simulations of several designs in COMSOL software.

The simulation results of the final model show that the obtained induced voltage can be effectively improved by optimizing the main parameters of the coil within a certain range. When the coil is made up of a coil wire with a diameter of 0.4 mm, wound into 1000 turns, the induced peak voltage obtained is 3.22 V, which represents a significant improvement over the initial design parameters.

Furthermore, the simulation shows that the optimized model is capable of achieving an effective voltage of 922 mV. This demonstrates the impact of the key design parameters on the system output, thus confirming the potential application value of enhanced pneumatic cylinders with energy harvesting capabilities.

Dual-fuel diesel engines using hydrogen as a secondary fuel source are a promising technology for reducing emissions while maintaining engine performance. However, optimizing these engines for all three aspects (performance, emissions, and vibration) simultaneously presents a challenge.

This study aimed to address this challenge by employing Response Surface Methodology, a statistical technique used to optimize multi-variable processes. The goal was to find the ideal combination of engine load, hydrogen flow rate, and compression ratio that would maximize Brake Thermal Efficiency while minimizing Brake-Specific Fuel Consumption, Nitrogen Oxide emissions, and engine vibration.

A Box-Behnken design, a specific type of design optimization with three factors and three levels, was employed. The experiment evaluated the impact of three key factors: engine load (ranging from 0 - 12 kg), hydrogen flow rate (0-15 L/min), and compression ratio (16 to 18:1). The effects of these factors on performance, emissions, and vibration were measured.

The results revealed a trade-off between achieving optimal performance and minimizing emissions. The highest Brake Thermal Efficiency and lowest Brake-Specific Fuel Consumption were achieved at a high compression ratio (18:1), maximum hydrogen flow rate (15 L/min), and under full engine load (12 kg), corresponding to a brake power of 3.5 kW. However, these conditions also resulted in higher NOx emissions and vibration levels. Conversely, minimizing NOx and vibration occurred at a lower compression ratio (16:1), with the same maximum hydrogen flow rate (15 L/min), but at a significantly reduced engine load (3 kg), resulting in a much lower brake power of 0.875 kW.

These findings highlight the complex relationship between performance, emissions, and vibration in a hydrogen-diesel dual-fuel engine optimized using Response Surface Methodology. While optimal conditions were identified for specific goals, achieving all desired characteristics simultaneously across the entire operating range remains a challenge.

A Smart Functionally Graded (SFG) porous beam is a Functionally Graded (FG) Porous beam consisting of a piezo-electric layer integrated on the top layer.

This research work addresses the lack of information by examining the bending as well as elastic buckling performance of SFG beams having two distinct Porosity Distributions (PDs). The main purpose of this research work is to study and analyze the bending deflections as well as CBLs of SFG beams with two different PDs, considering various boundary conditions, voltage levels (20 V and 100 V), and changes in slenderness ratio.

The objectives of this work are as follows: to analyze the impact of variations in voltage levels and slenderness ratios on the critical buckling and bending properties of the SFG beam and to showcase the effect of variation in the slenderness ratio on the dimensionless normal stress through the thickness of the Hinge-Hinge beam.

The research work analyzes the elastic buckling as well as static bending of Smart Functionally Graded (SFG) porous beams, considering the equations derived from the Timoshenko beam theory. To simulate the results and analyze the various effects, the ANSYS software has been utilized in this paper.

This research work examines how the slenderness ratio impacts the maximum deflection, CBL, along with stress distribution. Experimental data demonstrates that as the slenderness ratio increases, CBL reduces, and maximum deflections in SFG porous beams increase. Also, it has been observed that normal stress distribution shifts from linear to non-linear and changes significantly. Further, the PDs significantly affect the static bending as well as the buckling performance of the beam. The symmetric distribution pattern provides superior buckling capability and enhanced bending resistance compared to the unsymmetric distribution pattern. Additionally, it has been found that as the voltage across the SFG increases, the buckling load increases and the deflection of the beam decreases.

This research work has analyzed the effects of slenderness ratio and voltage level on the Critical Buckling Load (CBL) and bending properties of SFG porous beams, considering four different boundary conditions and a fixed set of parameters. The key findings of this paper are that as the slenderness ratio increases, the CBL decreases, and distribution shifts from linear to nonlinear region. Changes are significant, whereas maximum deflection increases. A significant effect is observed in the performance of static bending and buckling of SFG beams. It has been investigated that with an increase in voltage across the SFG beam, the buckling load increases, whereas the maximum deflection of the beam decreases.

Due to the recognition and further promotion of green and low-carbon concepts worldwide, Stirling refrigeration technology has gained people's attention for its significant advantages, such as high cooling capacity, high efficiency, and strong reliability. In recent years, related products have gradually entered the field of civilian low-temperature refrigeration. One of the key research directions is to achieve better refrigeration performance at lower costs.

Through simulative analysis and experimental verification, Free piston Stirling refrigerators (FPSCs) have better economic and performance advantages using non-metallic materials.

This paper analyzes an FPSC using Polyethylene naphthalate (PEN) material. The main losses and performance of the regenerator are analyzed about the impact of packing porosity and regenerator length. The actual performance obtained through experimental verification is compared with an FPSC with metal packing.

Experimental verification was conducted, and it was found that FPSC using non-metallic materials with a porosity of 52.4% had better performance. Some details of the patent are shown in the article. The COP of 25w@-76°C is 0.16, which is close to the performance of the PFSC using 200 mesh wound wire.

The cooling performance using non-metallic materials is similar to the FPSC using metallic materials, and the latter has great optimization potential and development prospects with lower cost.

Bolt loosening detection plays a crucial role in ensuring structural safety. Existing research using deep learning methods has the drawback of being applicable to limited scenarios and typically requires at least two frames of images for comparison in subsequent angle detection, with a limited range of detectable angles.

In this study, a color segmentation method was first used to separate the red square gasket placed between the bolt and the base, thereby locating the bolt area; then, the image was perspective-corrected using the four corners of the red square gasket; finally, the red mark bars on the bolt and base were separated using the same color segmentation method, and the geometric moments of the connected domains of the mark bars were processed, combined with vector processing techniques, to achieve quantified detection of bolt loosening angles within 0~360 degrees using a single frame image. This patent-pending method demonstrates a significant advancement over existing techniques. In the verification experiments, 150 images were collected from different shooting angles and distances, and the bolt areas to be tested were located using the color segmentation method, all with an IOU (Intersection over Union) greater than 0.9317. Subsequent experiments set different variables, including different shooting distances, bolt loosening angles, perspective angles, lighting conditions, bolt types, and image rotation angles.

The results demonstrated that the method presented in this study could accurately detect bolt loosening angles in multiple scenarios, offering a robust solution where traditional methods fall short.

Hence, it is capable of measuring loosening angles within the range of 0~360 degrees using only a single frame image, marking a significant patentable innovation in the field of structural safety monitoring. Future developments will focus on refining this technique for automated, real-time monitoring systems, enhancing its applicability and effectiveness in critical infrastructure maintenance.

Research on alternative fuels for internal combustion engines is crucial due to climate change and energy security concerns. Ethanol-blended gasoline has been a popular alternative fuel, but biomass limitations restrict its widespread use. Methanol offers a solution as it can be produced from non-food sources, extending ethanol's availability.

This study explores a ternary fuel blend consisting of gasoline, ethanol, and methanol as an alternative to binary gasoline-ethanol blend. The objective is to investigate if the iso-stoichiometric ternary blend offers equivalent fuel properties to E50 (Ethanol 50%, Gasoline 50% (v/v)) gasohol while potentially enhancing engine performance, reducing emissions, and improving combustion characteristics.

A single-cylinder, four-stroke, port fuel injection spark ignition engine was used. The engine was tested with three fuels: pure gasoline, E50 blend, and an equivalent iso-stoichiometric GEM blends. Engine tests were conducted at constant load with varying engine speeds. Performance, emission, and combustion parameters were experimentally measured and compared across all fuels.

E50 and its equivalent blends improved brake thermal efficiency but increased brake specific fuel consumption compared to gasoline. It significantly reduced unburned hydrocarbon and carbon monoxide emissions but slightly increased nitrogen oxide emissions.

Formulated E50 equivalent blends have identical air to fuel ratio, lower heating values as conventional binary E50 gasoline-ethanol blends. The study suggests that iso-stoichiometric GEM blends have the potential to be a viable alternative drop-in fuel for E50 in internal combustion engines. The future advancements in GEM blends, particularly in optimizing ratios, could lead to patentable inventions.

The unconventional thermal machining method of laser cutting is extensively used. Using this method, any material, essentially, having intricate geometries is machined accurately. The primary purpose of the current paper is to investigate how process factors affect kerf width for CO2 and fiber laser machining of the SS 316L method. This work mainly focuses on an experimental study of CO2 and fiber laser machining for SS 316L.

Changing process variables, including gas pressure, laser power, and cutting speed, the cut characteristics are assessed using the measurement of kerf width. A bystronic laser machine is used for the experimentation.

The design of the experiment (DOE) technique is applied using the response surface methodology and Box Behnken design. In this, three factors and two levels are chosen, resulting in 17 trial runs. ANOVA is used to perform mathematical computations. This paper also covers the research on SS 316L laser machining and identifies the optimized parameter. The major finding of this research is that changing the laser power affects the kerf width. The CO2 and fiber laser processing results in optimum kerf width values of 0.5726 mm and 0.3950 mm, respectively.

This study contributes to the understanding of laser machining of SS 316L and is a valuable resource for potential patent applications related to laser cutting technologies and optimized machining parameters.

When the crawler engineering vehicle is driving in the field, the uneven ground has a very severe vibration impact on it, which affects efficiency and comfort. This paper discusses various patents and designs of a new type of sliding viscoelastic suspension for crawler engineering vehicles.

The purpose of the study was to analyze the influence of piecewise stiffness and damping parameters of the new suspension on the vibration reduction performance of the crawler engineering vehicle to provide a theoretical basis for the rational design of suspension parameters in order to better solve the problem of severe vibration and impact on the walking mechanism of crawler engineering vehicles.

In this study, recent patents on crawler engineering vehicle suspension have been investigated, and a new type of crawler engineering vehicle with sliding viscoelastic suspension has been designed. A single degree-of-freedom piecewise asymmetric nonlinear vibration model has been established according to the load-displacement test curve of the new type of sliding viscoelastic suspension. According to the average method, the approximate analytical solution of the vibration model has been obtained, and then the system parameter values have been changed to analyze the influence of the change on the vibration reduction performance of the vehicle.

The resonance frequency of the crawler engineering vehicle could be avoided by using the new type of sliding viscoelastic suspension; the force transmissibility coefficient rose slowly in the natural frequency resonance region, and the damping performance has been found to be better. The amplitude of vibration displacement changed a little, meeting the requirements of bearing strength and stability under heavy loads. It has been found suitable for working under low frequency and large load conditions, and its mechanical characteristic parameters matched the loaded mass.

The new type of sliding viscoelastic suspension for crawler engineering vehicles can improve the vibration reduction performance of the crawler engineering vehicles, the service life of the vehicle components, and the comfort of driving. The theory and analysis method used in this study can be applied to the design optimization of high-quality viscoelastic suspension.

3D printing has become an activity changer in some sectors allowing the creation of personalized parts. With its growing popularity in areas needing mechanical capabilities, it is essential to grasp how the printing settings impact the mechanical traits of the printed pieces.

This paper presents a novel investigation into the impact of critical 3D printing parameters on the mechanical characteristics of polylactic acid (PLA), a widely used biocompatible and biodegradable polymer. Our experimental approach systematically evaluated the effects of various printing parameters including infill density, raster orientation, outline overlap, and print speed on the printed parts' tensile strength and Young's modulus. This could prepare the way for future patent applications in 3D printing optimization.

The results consistently showed that increasing the infill density and outline overlap improved tensile strength and Young's modulus. However, higher print speeds decreased both underscoring the practical application of our unique findings. This research is a pioneering effort providing engineers and designers with valuable direction for working with 3D-printed PLA parts in aerospace, automotive, and biomedical applications.

It significantly adds to the expanding corpus of research on the connection between 3D printing process variables and the mechanical characteristics of advanced polymeric materials.

During excavator operation, drivers often need to work continuously for a long period of time, and this work pattern can greatly reduce work efficiency. In addition, drivers maintain a fixed posture for a long time to operate the excavator, which can cause the phenomenon of muscle fatigue and joint discomfort, and even cause muscle strains and other injuries.

In order to protect the driver's health and work efficiency, the excavator cab is optimized and designed to reduce the harm to the human body through reasonable improvement for long time work, so as to improve the work efficiency.

Inspired by the patent, 16 muscles of human body were selected to conduct muscle fatigue analysis experiments on 11 operation processes of excavator to obtain the optimisation indexes, followed by the establishment of biomechanical model of human upper limbs and lower limbs according to the experimental results, and the construction of optimization model based on the value of the minimum joint moments, and finally, the optimized layout of excavator cab was re-optimized by using the whale optimization algorithm.

After 600 iterations of the algorithm, the total joint torque decreases from 395 N*m to 348.2 N*m. In the optimised excavator, the driver's total RULA score decreases from 4 to 3 when performing the right turn, left turn and backward action, while the total RULA score decreases from 5 to 4 when performing the lowering arm, extending arm, shovel unloading and left rotation action.

The driver is more likely to cause muscle fatigue when controlling the excavator to perform forward movement and lower arm movement, the optimization of joystick position and length, pedal position, and seat height using whale algorithm improves the driver's comfort during operation and reduces the fatigue during operation accordingly. The findings of this study can provide a reference for related patent research and development.