Characterization of temperature rise of carbon ceramic brake discZhang, Zhenxian; Zheng, Shize
doi: 10.1088/1742-6596/2827/1/012011pmid: N/A
Carbon ceramic can be utilized in the manufacture of new brake discs for trains with high speed as a new composite material. In this article, temperature rises of C/C-SiC discs in emergency braking are simulated using conducting the front-head train model containing brake discs, and simulation results are analyzed with those of steel brake discs. With 400 km/h braking speed, the temperature peak of carbon ceramic disc can reach 1098.56 K at 86.3 s under braking conditions of emergency.
Research on gear whine evaluation method based on transmission error sensitivityDai, Ling; Liu, Yuan; Jia, Yuan; Zhou, Wentai; Zhang, Anwei
doi: 10.1088/1742-6596/2827/1/012024pmid: N/A
The issue of noise control for electric vehicles has gradually become prominent, and gear whine noise, as a key factor, is crucial for improving the overall performance and quality of vehicles. This paper discusses the transmission error, a key parameter leading to gear whine, and analyzes the influence of load and gear micro modification on the distribution of transmission error, to achieve comparison and optimization of different axle plans. In addition, by statistical analysis of the distribution of manufacturing errors, it is concluded that they accord with a normal distribution. Then, the weighted transmission error is obtained considering error probability distribution, which provides a new approach for evaluating the sensitivity of gear whine noise to manufacturing errors, in order to solve the issue of noise consistency in large-scale production.
3D printing turbine slicing path optimization based on FDM technologyChen, Junwei; Yu, Jiaqi; Zhang, Yinglong
doi: 10.1088/1742-6596/2827/1/012018pmid: N/A
In 3D printing technology, optimizing the slicing path is very important for printing efficiency and forming quality. In this study, the slicing path of the turbine STL model in 3D printing based on FDM technology is optimized. By improving the traditional slicing algorithm, data redundancy is reduced, and the efficiency of path generation is improved. An index-based optimization slicing algorithm is proposed, which effectively improves the efficiency of the algorithm, reduces the system consumption, and achieves more efficient slicing processing.
Elastohydrodynamic lubrication analysis and temperature field simulation of gear systemYuan, Mengjia; Lin, Tengjiao; Chen, Bingkui
doi: 10.1088/1742-6596/2827/1/012031pmid: N/A
The gearbox is one of the key components in the aero engine. In the process of high-speed operation, the internal temperature of the gearbox rises significantly, which seriously affects the service performance of transmission equipment. Based on the meshing principle and Herz contact theory, the basic meshing parameters are analyzed, and the comprehensive friction coefficient and heat flux are solved. According to the principle of convective heat transfer in a rotating disc and the frictional heat diffusion model, the CHTC (convective heat transfer coefficient) is analyzed. The FE model of the gear system is built based on ANSYS software, and the temperature distribution is analyzed by loading thermal boundary conditions with the APDL program. The calculation results indicate that the middle of the tooth tip or root of the gear has the maximum temperature. The research provides some reference values for the calculation method of the temperature field of the gear system under elastohydrodynamic lubrication.
Effect of ball milling conditions on the microstructure for alumina-based ceramic with nano-silica additivesZhao, Liping; Xu, Jinyun; Zhang, Yu; Zhang, Ziqi; Li, Ming; Peng, Zhe; Zheng, Chunming; Sun, Xiaohong
doi: 10.1088/1742-6596/2827/1/012005pmid: N/A
Alumina-based ceramics, known for their excellent high-temperature stability and tensile strength, are utilized across various sectors like metallurgy, aerospace, and chemicals as thermal insulators and reinforcements. The mechanochemical method, which involves mechanical actions like stirring and grinding to induce chemical reactions without solvents, offers a green, time-efficient approach with minimal pollution. This technique is pivotal for nanomaterials preparation. This study successfully crafts nano-silica-enhanced alumina-based ceramics via mechanochemical methods. The impact of mechanochemical processes on ceramic properties is assessed through particle size, N2 adsorption, and various microscopic analyses.
Mechanical simulation analysis of an electric scroll compressorYao, Wenxu; Liu, Mingli; Gong, Chaoyue; Zhao, Tengshan; Gao, Yidan
doi: 10.1088/1742-6596/2827/1/012025pmid: N/A
As a precision automotive component, electric scroll compressors have high requirements for reliability. In order to save the cost of environmental testing and shorten the market cycle of new products, the modal parameters of a compressor are measured, and the first six modal parameters are obtained. Secondly, the simplified finite element model of the compressor is established, modal analysis is carried out, and the modal frequency error obtained by the two methods is controlled within a reasonable range to ensure the accuracy of the modeling. Finally, based on the established simulation model, the structural response and stress of the compressor under various working conditions, such as sinusoidal vibration and random vibration, are analyzed, and the extreme values of displacement and stress are obtained. The results show that the structural design of the compressor meets the requirements of the environmental test of on-board equipment. The test and simulation methods used in this paper also have certain reference significance for other mechanical equipment.
Dynamic positioning system of ships with RBF neural network compensatorZhao, Ganyu; Yu, Menghong
doi: 10.1088/1742-6596/2827/1/012032pmid: N/A
In Dynamic Positioning, traditional control methods lack stability, while neural networks and reinforcement learning have become research hotspots. By learning decision-making strategies from environmental observation data, we can adapt to environmental changes in real time and achieve optimal control effects. We also design a reward function to evaluate control performance. Dynamic inversion control is a control strategy that transforms nonlinear systems into linear systems. To address the issue of ship dynamic positioning, we propose a novel controller design method by combining RBF neural networks with dynamic inversion control. Its effectiveness has been verified through simulation experiments, demonstrating its potential and value in practical applications. This method will help improve the positioning accuracy of ships and optimize control performance.
Research on point pressing process of curved parts of thick plates with asymmetric double curvature of high strength steelJi, Han; Gao, Shuang; Tang, Min; Yu, Banhai; Li, Xu
doi: 10.1088/1742-6596/2827/1/012034pmid: N/A
High-strength steel asymmetric double-curvature thick plate curved parts are widely used in shipbuilding, nuclear power and other industries, but their accurate forming has been a challenge due to their high strength, large size, asymmetric structure and serious springback. In this paper, the simulation analysis study of spot press forming is carried out with large-size double-curvature spherical thick shells as the research object, and the effects of mould surface size, mould radius of curvature on the results of pressing and forming of asymmetric double-curvature curved thick plate parts made of high-strength steel are analyzed. The results show that the pressing route of pressing the centre of the slab first and then carrying out point pressing along the line of symmetry to the surroundings has the best forming effect. Different mould profile dimensions and radius of curvature of the profile have a great influence on the simulated forming results.
Research on channel-exposed carbon-based FET humidity sensorChen, Qingqing; Zhang, Yong
doi: 10.1088/1742-6596/2827/1/012017pmid: N/A
The ability to detect humidity is crucial for a variety of sectors, including industrial manufacturing, meteorological surveillance, and the preservation of materials, among others. Field effect transistor (FET) based sensor, renowned for its signal amplification effect, plays a pivotal role in detecting trace-level analytes with high sensitivity. Our work demonstrates the preparation of a humidity sensor based on carbon-based FET architecture, employing micro-nano processing techniques. In this work, semiconducting carbon nanotubes serve as the sensing material and channel at the same time. The outcomes indicate that the sensor exhibits a linear response ranging from 0% to 80% relative humidity (RH) and good repeatability. It also shows long-term stability in a 40-day test, proving potential applications in FET-type humidity sensors.
Deformation and stress analysis of frame and hub bearing based on FE simulationLiu, Hailong; Cao, Shukun; Zhao, Dong; Zhu, Xiaoxuan; Zeng, Li; Zhang, Yihua
doi: 10.1088/1742-6596/2827/1/012019pmid: N/A
By using ANSYS Workbench, the deformation and stress of the frame and hub bearing were studied. For the deformation analysis of the frame, the maximum deformation of the original frame was 2.99 mm under no-load conditions, while the deformation of the improved frame was only 1.88 mm. By making a prototype of the frame and measuring the experimental deformation at the position of the radiator bracket under no-load conditions, it was found that the error between the test result and the simulation result was small, thus verifying the established FE model. Subsequently, the deformation of the frame was studied under full load conditions, and it was concluded that the maximum deformation was 2.47 mm, which was still less than the deformation of the original frame under no load conditions. For the FE simulation analysis of the double-row tapered roller hub bearing, compared with the inner ring, retainer, and outer ring, the equivalent stress of the tapered roller was up to 507.5 MPa, but it still didn’t exceed the yield strength, confirming the rationality of the designed bearing structure.