Jaw Functional Orthopedics and Cranoficial Growth
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Experimental analysis of running wheel for a straddle monorail vehicle
Get PDFThis article conducts in-depth research on the force analysis of the test running wheel of a certain type of straddle monorail vehicle, based on the tire six-component force test and wheel dynamic stress test. The main research objective is to accurately identify the factors affecting the wheel strength, thereby providing a solid foundation for subsequent design optimization and safety enhancement. The research commences with a meticulous calibration of the vehicle connecting rod in the laboratory, aiming to acquire the “force-strain” coefficients under both tension and compression conditions. A novel approach lies in the verification of calibration accuracy through a detailed comparison with experimental results, ensuring the reliability of subsequent data acquisition. By strategically installing displacement sensors at various positions to measure the vehicle's dynamic displacement and detecting the strain of the connecting rod, the study innovatively calculates the six-component force data of the tire, which provides a comprehensive data basis for analyzing the forces acting on the wheel hub. Then evaluating the fatigue strength of the wheel hub under AW0 and AW3 operating conditions based on the IIW standard, the research uncovers unique findings. It is revealed that, although the maximum dynamic loads of the vertical force of the running wheel, the lateral force of the guide wheel, and the lateral force of the stabilizing wheel are within the limit load range with a certain safety margin, there are 1 point and 3 points on the wheel hub under AW0 and AW3 working conditions, respectively, that fail to meet the fatigue strength criterion requirements. The maximum equivalent force amplitude at Measurement Point 3 of the inner hub reaches 51.4 MPa, while the calculated service mileage is only 31,000 kilometers. This discovery is of great significance as it precisely pinpoints the weak points of the wheel hub, which is a major contribution to the field. Moreover, during the analysis of the wheel hub's dynamic stress during emergency braking and the influence of polygonal wear on it, the research confirms that there is no abnormal change in the wheel hub’s dynamic stress during emergency braking, and the polygonal wear of the tire shoulder has a negligible impact on the wheel hub’s dynamic stress. These results not only calculate the six-component force data of the tire but also break new ground in understanding the interaction between different factors and the wheel hub’s performance
Finite element analysis and vibration simulation of electromagnetic imaging sensor housing based on ANSYS
Get PDFMining sensors work in harsh environments and are subject to complex vibrations. Its internal structure is prone to strength failure or fatigue damage. This paper focuses on the structural design of the front discharge and receiver housing inside the electromagnetic imaging sensor for coal-rock demarcation detection. Static analysis, modal analysis, and random vibration simulation were performed using ANSYS Workbench software to verify its reliability and strength in mining. In the static analysis, the thickness of the designed housing is 2 mm. The maximum equivalent elastic strain after applying a pressure of 0.5 MPa to the housing is 0.133 %, much less than the criterion of material fracture strain. This proves that it has excellent strength properties and will not experience strength failure. Modal analysis shows that the first-order intrinsic frequency of the housing is 3298.7 Hz. It is much higher than the vibration frequency in the actual working environment, which can effectively avoid resonance and improve the reliability of the structure. Random vibration simulation results show that the housing's maximum equivalent force and displacement are within the safe range, and the impact on the structural performance is negligible. These results provide a theoretical basis for the optimal design of the sensor housing and its application in complex vibration environments
A new self-adaptive anti-galloping device in suppressing conductor galloping in transmission lines
Get PDFConductor galloping is a serious threat to transmission line integrity, inducing excessive conductor tension that may lead to catastrophic failures including conductor breakage and tower collapse. This study proposes a novel self-adaptive anti-galloping device (SAGD) to mitigate galloping amplitudes and reduce associated risks. In this paper a novel self-adaptive anti-galloping device (SAGD) to mitigate galloping amplitudes and reduce associated risks was proposed. The structural design scheme of the device is provided, and its operation sequence was verified through static loading experiments. Conductor free-falling experiments validated the SAGD's vibration control performance, with test results demonstrating its practical applicability for transmission line protection. A finite element model for the conductor-SAGD system was developed, enabling numerical simulation of galloping displacement time history and analysis of endpoint support reaction dynamics. The device's galloping suppression effectiveness is systematically evaluated under varying stroke lengths and threshold conditions
Design and verification of a new type of hydraulic vibration isolator for high-speed train floors
Get PDFWith the development of high-speed trains, the requirements for noise, vibration, and comfort are becoming increasingly stringent. The train body floor, as one of the main pathways for vibration transmission, is crucial to be treated for vibration reduction and noise attenuation. This paper, in response to this demand, has developed a new type of floor vibration isolator specifically for high-speed trains. Through finite element simulation analysis and experimental verification, it has been proven that this vibration isolator can effectively reduce the vibration of the train body floor and significantly enhance the NVH (Noise, Vibration, and Harshness) performance of the train
Improved cubature Kalman filter for vehicle state estimation and measurement
No full textThe accurate estimation of vehicle state parameters has a significant impact on the active safety system of automobiles. Accurately obtaining vehicle operating parameters is the foundation and prerequisite for active safety control of vehicles. In response to the limited estimation accuracy of the traditional CKF method, the CKF was extended to fifth-order according to the third-order sphere-radius cubature rule, making it have the accuracy of fifth-order Taylor series expansion. At the same time, singular value decomposition was used instead of traditional Cholesky decomposition to form a fifth-order cubature Kalman filter (SVD-FCKF) estimator for singular value decomposition. Then, the SVD-FCKF was validated using the Carsim and Matlab/Simulink joint simulation platform. Finally, the effectiveness of the proposed method was verified through virtual experiments. The results show that the improved SVD-FCKF estimator can effectively improve the accuracy and stability of vehicle state estimation, with overall estimation performance better than the CKF estimator and has strong adaptability under high and low adhesion coefficient conditions. The research results can provide theoretical support for the active safety research of intelligent vehicles and have practical application value
Artificial intelligence-based stock market price prediction, a review
No full textThe stock market, a cornerstone of the global financial system, is characterized by its dynamic and volatile nature, which makes accurate price-trend prediction challenging. However, traditional statistical models often fail to capture this complexity. Recent advancements in Artificial Intelligence (AI), particularly Machine Learning (ML) and Deep Learning (DL), have transformed stock market forecasting by using diverse datasets and algorithms. This review examines recent studies on AI methodologies for stock market price trend prediction models by analyzing architectures, datasets, performance metrics, and limitations, with a focus on hybrid models, sentiment analysis, and dataset diversity. Hybrid approaches, including the Multi-Model Generative Adversarial Network Hybrid Prediction Algorithm (MMGAN-HPA), K-means long short-term memory (LSTM), and LSTM autoregressive output (LSTM-ARO), improve predictive accuracy by combining statistical methods with deep learning. Sentiment analysis models such as Stock Senti WordNet (SSWN) and Hybrid Quantum Neural Network (HQNN) integrate social media sentiment to capture market dynamics. Real-time frameworks that use stream processing show promise for high-frequency trading applications. This review addresses key challenges including data noise, nonstationarity, overfitting risks, and black-box model interpretability. Solutions include GAN-based synthetic data generation, transformer-based architectures such as SpectralGPT, and optimization techniques for computational efficiency. This review provides a taxonomy of AI-based approaches, while identifying gaps for future research. These findings highlight the potential of AI in financial forecasting while emphasizing the need for interdisciplinary collaboration to address its limitations in data quality, methodology, interpretability, and ethics
Methods to increase the throughput and carrying capacity of the “Angren-Pop” railway section in line with expected transit freight flows from the “China-Uzbekistan-Kyrgyzstan” railway project
No full textThe development of the “China-Kyrgyzstan-Uzbekistan” railway (hereinafter referred to as the CKU) can be cited as a promising project to increase transit cargo flows in our country. In organizing the uninterrupted transportation of transit freight flows planned to pass through the territory of our country as a result of the implementation of this project, the “Angren-Pop” railway section, which includes the 19.2 km long “Kamchik” tunnel, is of great importance. This article analyzes the impact of the development of the CKU railway on the throughput and carrying capacities of the “Angren-Pop” railway section. The current maximum freight capacity of the “Angren-Pop” railway section has been studied. The results show that this section is not capable of handling the expected volume of transit cargo. This substantiated the need to find solutions for effectively increasing the carrying capacity of the section while ensuring an economically rational balance. Methods for effectively increasing the carrying capacity of the section are recommended, including the systematic implementation of measures such as increasing the standard weight of freight trains, raising the operating speed on the section, and using electric locomotives with high tractive power
Key construction technologies for in-situ reconstruction of a continuous girder bridge onto a steel truss arch bridge
No full textThis study explains the challenges of reconstructing a continuous beam bridge and its effects on the performance of adjacent structures. Combined in-situ demolition and modification of continuous beam bridges with the new construction of steel truss arch bridges, an integrated construction method is established. Taking a bridge as a construction platform, the temporary fixation technology is used for the tie beam hook. Various erection techniques of the bridge and tie beam construction support frame, as well as the construction techniques of Truss steel arch and wind bracing are studied and explored. In addition, the method of simultaneous disassembly and construction methods of crossbeams are also studied. Finally, a new technology is developed to reconstruct Truss arch bridge on continuous beam bridges
Erratum: Bispectrum analysis based on dual channel homologous information fusion and its application in fault diagnosis
No full textRandom parametric nonlinear vibrations of a discrete mechanical system protected from vibration
No full textIn this work, the issue of checking the dynamics of nonlinear vibrations of a mechanical system protected from vibrations in case of random parametric excitations is considered. Using the Ito method, the analytical expressions of the mean square values of the absolute accelerations of the mechanical system and the dynamic absorber were determined. Statistical linearization method based on Davidenko's hypothesis was used to determine mean squared values. The average square value change of the random parametric vibration of the mechanical system protected against vibrations with the dynamic absorber at different values of the parameter describing the width of the vibration spectrum was analysed. It is shown that if the parameter describing the width of the vibration spectrum is taken smaller, the mean square value of the random parametric vibration of the protected object combined with the dynamic absorber will have a smaller vibration. At different values of the parameter of the hysteresis loop, the change of the mean square value of the random parametric vibration was analysed and appropriate conclusions were drawn