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Through research on the mechanism of vibration compaction, a “Roller-Subgrade” coupling system model for roadbed vibration compaction construction was established, and dynamic analysis and calculations were performed on this model. Meanwhile, the MATLAB software was utilized to conduct simulation studies on this coupling model, with detailed elaboration on the determination of basic simulation parameters and the design of corresponding simulation programs. Through simulation analysis, the displacement and velocity response of the vibratory wheel of the vibratory roller under fixed mechanical and soil parameters were explored.

A coupled sliced finite element-infinite element model is developed to analyse the train-induced environmental vibration from metro tunnel by treating the tunnel-ground system as a longitudinal periodic structure. Based on the auxiliary periodic train-track coupling model, this model enables one to select any periodic spatial range of the tunnel-ground system to analyse the response of the longitudinally infinite spatial domain, which will significantly enhance the computational efficiency. Unlike the existing 2.5D models and periodic models accounting for the train-induced environmental vibration, the significant reduction of the degrees of freedom of system in this model does not require a wavenumber transformation, thus only the formation knowledges of system governing equation in the normal space domain rather than in the transformed domain are needed. By comparing the simulated results with the corresponding measured ones, the proposed model is well validated. The transmission features of the metro train-induced environmental vibration, together with the impact on the rail pad stiffness and train velocity on the metro train-induced environmental vibration are also detailed investigated using the proposed model, with some important issues that deserve but have failed to attract due attention clarified.

In the early construction of cavern leaching in salt cavern gas storages, the inner leaching tubing is often blocked, frequently leading to the bending deformation phenomenon of the leaching strings, which can result in out-of-control cavity shapes. It is difficult to monitor the stress, vibration, and morphological changes of the inner tube during the construction of a cavity. There are few research results in this field at home and abroad, and they are limited only to preliminary explorations of the mechanism or summaries and speculation of the field operation. In this paper, an experimental device for testing the dynamic characteristics of salt cavern leaching strings is developed based on the similarity principle. The device is used to simulate two types of operation processes, i.e., the direct and reverse circulation leaching processes. The experimental data are processed using the modal analysis method to obtain the vibration characteristic parameters of the inner leaching tubing in the circulation process with identical flow rates inside the tubing and the annular region. The following main conclusions can be drawn: The circulation mode has no significant effect on the vibration frequency of cavern leaching strings. The deformation characteristics of cavern leaching strings during direct and reverse circulation are identical, featuring maximum deformation at the bottom and minimum deformation in the middle. The maximum deformation of cavern leaching strings during reverse circulation is about 1.5 times that during direct circulation. Through an experimental investigation and analysis, the effects of the water injection rate and the cavern leaching method on the vibration frequency and bending deformation of cavern leaching strings was determined, providing a reference for further solving the bending problem of cavern leaching strings in combination with engineering practice.

Available hydropneumatic suspension simulation test benches have insufficient loading accuracy and limited functionality rendering them unsuitable for performance testing of heavy vehicles with this type of suspension. Therefore, a multi-functional compound simulation test bench was designed that used an electro-hydraulic proportional control technique. A mathematical model was established to describe the hydraulic loading system, and the transfer function of the system was derived. The gain and phase margins confirmed the stability of the system. A simulation model was established in the Simulink environment and step and sine signals of different frequencies were applied separately to analyze the dynamic characteristics of the system. The results showed that the system responded slowly and exhibited phase lag and signal distortion. The dynamic characteristics of the system were improved by incorporating an adaptive fuzzy PID controller. Simulation results showed that the response of the system to the step signal stabilized at the preset value within 0.3 s with no oscillation or overshoot. The improved system performed well in replicating the random vibrations of heavy vehicles operating on Class B and C roads. This confirmed that the system can satisfy the loading requirements of heavy vehicle hydropneumatic suspensions and can be used as a simulation test bench for such suspensions.

Bearing defects are one of the most important mechanical sources for vibration and noise generation in machine tool spindles. In this study, an integrated finite element (FE) model is proposed to predict the vibration responses of a spindle bearing system with localized bearing defects and then the sensor placement for better detection of bearing faults is optimized. A nonlinear bearing model is developed based on Jones’ bearing theory, while the drawbar, shaft and housing are modeled as Timoshenko’s beam. The bearing model is then integrated into the FE model of drawbar/shaft/housing by assembling equations of motion. The Newmark time integration method is used to solve the vibration responses numerically. The FE model of the spindle-bearing system was verified by conducting dynamic tests. Then, the localized bearing defects were modeled and vibration responses generated by the outer ring defect were simulated as an illustration. The optimization scheme of the sensor placement was carried out on the test spindle. The results proved that, the optimal sensor placement depends on the vibration modes under different boundary conditions and the transfer path between the excitation and the response.

Based on cognitive psychology theory, this study explores the doctrinal logic and practical path of higher education curriculum reform to enhance the effectiveness of higher education programs, with particular attention to improving students’ psychological quality and learning effectiveness. The study uses the finite element method and digital waveguide technology to simulate and analyze the stringed musical instrument. Accurate simulation of the vibration characteristics of the musical instrument is realized through the vibration equations of an ideal string and the principles of the digital waveguide algorithm. The experimental results show that the applied simulation technique can effectively simulate the vibration characteristics of the resonance box of the musical instrument, such as the ideal string vibration and the cavity coupling effect. In addition, the study involves the mathematical expressions of forced vibration and resonance and the effects of various materials on the modal frequencies of the resonance box. The application of artificial intelligence technology in studying acoustic properties of musical instruments significantly improves the accuracy and efficiency of simulation. It provides essential theoretical support for the design and production of musical instruments.

Unilateral vocal fold polyps can lead to incomplete glottal closure and irregular vocal fold vibration. Depending on polyp size and resulting dysphonia severity, voice therapy or surgery may be recommended. As part of voice therapy, patients may learn how to optimize intrinsic and extrinsic laryngeal muscle use to mitigate benign lesion effects, increase vocal efficiency, and improve voice quality. In this study, we used a low-dimensional mass model with a simulated unilateral vocal fold polyp and varied intra-laryngeal muscle activity to simulate vocal fold vibration across varied conditions. Differing muscle activation has different effects on frequency, periodicity, and intensity. Accordingly, learning how to optimize muscle activity in a unilateral polyp setting may help patients achieve the best possible periodic and most efficiently produced voice in the context of abnormal vocal fold morphology.

In this article, the computational methodology of the catenary–train–track system vibration analysis is presented and used to estimate the influence of vehicle body vibrations on the pantograph–catenary dynamic interaction. This issue is rarely referred in the literature, although any perturbations appearing at the pantograph–catenary interface are of great importance for high-speed railways. Vehicle body vibrations considered in this article are induced by the passage of train through the track stiffness discontinuity, being a frequent cause of significant dynamic effects. First, the most important assumptions of the computational model are presented, including the general idea of decomposing catenary–train–track dynamic system into two main subsystems and the concept of one-way coupling between them. Then, the pantograph base vibrations calculated for two train speeds (60 m/s, 100 m/s) and two cases of track discontinuity (a sudden increase and a sudden decrease in the stiffness of track substrate) are analyzed. Two cases of the railway vehicle suspension are considered – a typical two-stage suspension and a primary suspension alone. To evaluate catenary–pantograph dynamic interaction, the dynamic uplift of the contact wire at steady arm and the pantograph contact force is computed. It is demonstrated that an efficiency of the two-stage suspension grows with the train speed; hence, such vehicle suspension effectively suppresses strong sudden shocks of vehicle body, appearing while the train passes through the track stiffness discontinuity at a high speed. In a hypothetical case when the one-stage vehicle suspension is used, the pantograph base vibrations may increase the number of contact loss events at the catenary–pantograph interface.

Vehicles commonly suffer from the narrow-band noises and vibrations, usually a superposition of multiple sinusoidal signals, due to the excitations of engines, electrical motors, gear boxes, and other rotating mechanical parts. These excitations are transmitted to a reference point of some structure with certain transmission paths. The vibration signal measured at the reference point can be used for power system monitoring, fault diagnosis, modal analysis, noise analysis, etc. For convenience, researchers in a laboratory usually use shakers to generate expected narrow-band vibration signals acting on the vehicle structure reference points to simulate the vibration signals. However, there is a prominent difficulty in ensuring the amplitude and phase accuracy of each sub-frequency component simultaneously. In order to improve the accuracy of generating the expected vibration signal, this paper presents a multi-source vibration simulation control technology based on the tracking filter method. The main idea is to use the tracking filter to estimate the amplitude and phase of the target sub-frequency component accurately. Further, on the target sub-frequency, the drive signal of shakers is then corrected based on the amplitude and phase errors to achieve a more accurate target vibration signal. The amplitude and phase of each sub-frequency component in the excitation signal can be controlled independently. Compared with other Fast Fourier Transform (FFT)-based frequency domain analysis algorithms and numerical methods by solving the equations, the tracking filter method has a higher frequency resolution and higher accuracy. It can be easily realized in real time applications due to its simplicity. Finally, verification experiments are completed. The experimental results show that the multi-source vibration simulation control technology presented in this paper can achieve high-precision amplitude and phase on each sub-frequency component of the target vibration signals, which contain up to eight sub-frequency components.

Significant progress has been made in understanding the mechanisms and simulations of ice-induced shock vibrations due to continuous experimentation and simulation of vibrations induced by ocean platforms. However, the threat of such vibrations to bridges in cold regions with spring rivers remains significant. Currently, challenges persist in the numerical analysis methods applied to vibrations caused by collisions between ice and bridges in river channels. This difficulty primarily arises from the insufficient consideration of the impact of flow field coupling on ice-induced shock vibrations under various simulation conditions. This paper aims to analyze the influence of ice-induced shock vibrations arising from collisions involving bridges, ice, water, and air. It also compares the Semi-Arbitrary Lagrangian-Eulerian (S-ALE) and Arbitrary Lagrangian-Eulerian (ALE) methods, finding that the S-ALE method is better suited for complex flow-solid coupling analysis under the same model. Comparative analysis shows that the fluid effect period increased by approximately 30%, resulting in an 8% reduction in peak values. This confirms the applicability of the ice-induced shock vibration theory and demonstrates that factors such as velocity and thickness significantly impact these vibrations. The findings offer valuable insights for the numerical simulation of river ice-induced shock vibrations due to bridge-ice collisions in cold areas.