Dynamic Response Research Articles

Research on dynamic response of vertical displacement of runway pavement slab end under aircraft taxiing using novel FBG sensors

The vertical displacement dynamic response measuring at slab joints is crucial for pavement management. In order to obtain accurate dynamic vertical displacement response of slab end, this study developed a vertical displacement sensor based on Fiber Bragg Grating (FBG) technology, featuring an accuracy of 0.15 mm and a resolution of 0.015 mm, which embedded alongside other sensors into Lukou Airport taxiway. The time-history curves of vertical displacement of slab end at both joint sides were obtained, enabling a comprehensive capture of dynamic response during taxiing. In addition, finite element method (FEM) was conducted to simulate taxiing under varying aircraft types, wheel lateral deviation, and speeds. The findings revealed close alignment between FBG sensors and FEM results, with 0.18 mm average error for the sensor, clearly demonstrating its exceptional reliability. Additionally, the influence pattern of taxiing parameters on vertical displacement of slab end including wheel load and path were revealed using FEM.

State Dependency of Dynamic and Thermodynamic Contributions to Effective Precipitation Changes

Abstract Reliable projections of the future hydrological cycle are needed for designing adaptation and mitigation measures under global warming. However, uncertainties in the projected sign and magnitude of effective precipitation changes (precipitation minus evaporation, P − E) remain high. Here, we examine the state dependency of circulation, temperature, and relative humidity contributions to P − E changes in simulations of the Last Glacial Maximum (LGM), mid-Holocene, and abrupt quadrupling of the atmospheric carbon dioxide concentration. To this purpose, we apply a moisture budget decomposition and a thermodynamic scaling approximation to CMIP6/PMIP4 simulations with the Earth system model MPI-ESM1.2. We find that the importance of thermodynamic and dynamic contributions to P − E changes and the patterns of dynamic contributions depend strongly on the underlying forcing. Greenhouse gas forcing leads to a stronger thermodynamic response than dynamic response. The LGM ice sheets yield a large dynamic contribution with zonally heterogeneous patterns. Orbital forcing induces a predominantly dynamic response with a hemispherically antisymmetric structure. We also identify state-invariant features: The importance of temperature and relative humidity contributions to specific humidity changes is consistent across states, and the wet-get-wetter–dry-get-drier paradigm proposed for global warming holds in almost all regions dominated by thermodynamic contributions. By definition, the P − E budget and the respective thermodynamic, dynamic, and transient eddy contributions vanish in the global mean. Moreover, we find that for increasing length scales, the spatial variability of these contributions decays with similar rates. We suggest repeating our analysis for more models and states which could help constrain hydroclimate projections. Significance Statement We aim at improving our understanding of the influence of changes in winds and water vapor on the local balance between precipitation and evaporation. To this end, we compare simulations for two past climate states with an idealized high carbon dioxide concentration scenario. We find characteristics that depend on the underlying state and characteristics that are consistent across states. Our results help to identify what we can learn from past climate states about precipitation changes under future greenhouse gas emission scenarios. So far, we only analyzed simulations from one model. Therefore, we suggest to repeat our analysis with more models and for more past climate states to confirm our results.

Lateral dynamic response of partially embedded piles in the sea considering wave loads and wave-induced seabed dynamic response load distribution effects

Lateral dynamic response of partially embedded piles in the sea considering wave loads and wave-induced seabed dynamic response load distribution effects

Computer-aided design and construction of a novel electro-responsive ion-imprinted sensor for the individual/simultaneous detection of Cd(II) and Pb(II) in water environments.

A novel method for detecting Cd(II) and Pb(II) in water using composite ion-imprinted membranes (Cd@Pb-IIM/Ag@MOF@CHI) was developed. Pre-polymerization ratios were optimized via computer simulations and applied on Ag@MOF@CHI-modified electrodes using infrared light initiation. Characterization of the membranes through SEM and electrochemical methods revealed detailed morphology and composition. The sensor showed a dynamic linear response for Cd(II) and Pb(II) concentrations ranging from 1.1×10-9 to 1.2×10-6molL-1, with a detection limit of 1.0×10-10molL-1. In samples with various non-target ions, the sensor exhibited high selectivity, attributed to the optimal coordination ratio (Cd(II): Pb(II): PAR=1:1:3). Successful tests were conducted in tap, lake, and river water, highlighting its potential for environmental monitoring.

Dynamic Structural Responses of Tunnel Surrounding Disturbed Sand Retrofitted by Waste Tire–Derived Aggregate with Presence of Piles

Dynamic Structural Responses of Tunnel Surrounding Disturbed Sand Retrofitted by Waste Tire–Derived Aggregate with Presence of Piles

Dynamic time history response prediction through an experimentally trained deep gated recurrent units network using cyber physical real-time hybrid simulation

Dynamic time history response prediction through an experimentally trained deep gated recurrent units network using cyber physical real-time hybrid simulation

A deterministic model of surface profile degradation for evaluating time-varying mesh stiffness and dynamic responses of spur gear considering tooth surface wear evolution

A deterministic model of surface profile degradation for evaluating time-varying mesh stiffness and dynamic responses of spur gear considering tooth surface wear evolution

Experimental study on dynamic responses of a new semi-submersible supporting platform concept for 10 MW wind turbines

Experimental study on dynamic responses of a new semi-submersible supporting platform concept for 10 MW wind turbines

SPH modeling and experimental validation on power performance and dynamic response of a novel swing-wing wave energy converter

SPH modeling and experimental validation on power performance and dynamic response of a novel swing-wing wave energy converter

Dynamic response of novel floating wind turbine to freak waves during uninterrupted operation

This study focuses on the dynamic responses of a novel 15 MW deep-sea Floating Offshore Wind Turbine (FOWT) equipped with a specific heave plate and low-ballast (SHLB) to freak waves while in operation. To gain a more comprehensive understanding of the impact of freak waves on FOWTs, a three-column wave superposition model is employed to simulate abnormal waves. A fully coupled time-domain model of the innovative 15 MW semi-submersible FOWT is developed utilizing the FAST code. The transient dynamic performance of the FOWT is evaluated under both random and freak waves. The analysis covers foundation motion, blade and tower force, nacelle acceleration, and fairlead tension, among other responses. Based on this, wavelet analysis is applied to explore the time-frequency properties of freak waves as opposed to random waves. Furthermore, the effects of freak wave incidence angle and wind speed fluctuations on wind turbine operational efficacy are analyzed. The results unequivocally indicate that the peak responses in the impact zones across various components increase under freak waves. Freak waves exacerbate the maximum foundation motion, particularly in heave, surge, and pitch, and produce a shift in the high-frequency energy core of the wavelet transform. Fairlead tension is greatly raised due to surge amplification. The impact of freak waves generates a dramatic rise in nacelle axial acceleration. Moreover, under freak wave conditions, variations in wind speed have no discernible effect on the foundation motion excitation at the wave frequency but exhibit enhanced responses in the wind energy and natural frequency ranges. Wind speed predominantly affects the blade response, exerting minimal influence on tower base loads. The peaks of the foundation and blade follow a similar pattern in cases of wind-wave misalignment, whereas the tower differs slightly, with all responses reaching a maximum at 0°. These findings are significant in providing guidelines for the safe design and failure analysis of ultra-large FOWTs.

Effect of hydrodynamic coupling on dynamic response of perforated tube

Effect of hydrodynamic coupling on dynamic response of perforated tube

Study on Dynamic Response Characteristics and Optimisation of Common Rail Injectors

Study on Dynamic Response Characteristics and Optimisation of Common Rail Injectors

Comprehensive experimental investigation of dynamic response to fluctuating load of proton exchange membrane water electrolyzer

Comprehensive experimental investigation of dynamic response to fluctuating load of proton exchange membrane water electrolyzer

Research on wind-wave induced dynamic responses and energy dissipation mechanism of the offshore new floating tube platform with flexible photovoltaic array

Research on wind-wave induced dynamic responses and energy dissipation mechanism of the offshore new floating tube platform with flexible photovoltaic array

Predictive equations for earthquake-induced dynamic response and permanent displacements of slopes considering bedrock depth and impedance contrast

Predictive equations for earthquake-induced dynamic response and permanent displacements of slopes considering bedrock depth and impedance contrast

Hydrogen peroxide damage to rat liver sinusoidal endothelial cells is prevented by n-acetyl-cysteine but not GSH

Background: Reactive oxygen species (ROS) are prevalent in the liver during intoxication, infection, inflammation, and aging. Changes in liver sinusoidal endothelial cells (LSEC) are associated with various liver diseases. Methods: Isolated rat LSEC were studied under oxidative stress induced by H2O2 at different concentrations (0.5–1000 µM) and exposure times (10–120 min). LSEC functions were tested in a dose-dependent and time-dependent manner. Results: (1) Cell viability, reducing potential, and scavenging function decreased as H2O2 concentration and exposure time increased; (2) intracellular ROS levels rose with higher H2O2 concentrations; (3) fenestrations exhibited a dynamic response, initially closing but partially reopening at H2O2 concentrations above 100 µM after about 1 hour; (4) scavenging function was affected after just 10 minutes of exposure, with the impact being irreversible and primarily affecting degradation rather than receptor-mediated uptake; (5) the tubulin network was disrupted in high H2O2 concentration while the actin cytoskeleton appears to remain largely intact. Finally, we found that reducing agents and thiol donors such as n-acetyl cysteine and glutathione (GSH) could protect cells from ROS-induced damage but could not reverse existing damage as pretreatment with n-acetyl cysteine, but not GSH, reduced the negative effects of ROS exposure. Conclusions: The results suggest that LSEC does not store an excess amount of GSH but rather can readily produce it in the occurrence of oxidative stress conditions. Moreover, the observed thresholds in dose-dependent and time-dependent changes, as well as the treatments with n-acetyl cysteine/GSH, confirm the existence of a ROS-depleting system in LSEC.

Robust adaptive integral sliding mode control of a half-bridge bidirectional DC-DC converter

A novel approach to improving the dynamic response of a half-bridge bidirectional DC-DC converter is presented in this paper, particularly in the face of disturbances from internal or external sources. These converters, which are integral to the operation of DC microgrids, are responsible for stepping up or stepping down voltage as required. To optimize the converter's performance under varying conditions, we propose an adaptive integral sliding mode controller (AISMC) enhanced by particle swarm optimization (PSO). The proposed controller leverages the strengths of both super-twisting sliding mode control (STSMC) and adaptive control, providing a robust and responsive solution to the challenges posed by the converter's nonlinear dynamics. The system's stability is rigorously ensured through the application of Lyapunov stability criteria, which underpin the enhanced performance of the controller. Simulations conducted in the MATLAB/Simulink environment demonstrate that the AISMC-PSO outperforms conventional control strategies, offering superior stability, robustness, and precision. The results clearly indicate that the proposed approach minimizes errors and enhances the overall efficiency and reliability of the bidirectional half-bridge DC-DC converter, making it a highly effective solution for DC microgrid applications.

Stiffness identification of bridge by using the dynamic response of a passing dual axle vehicle based on synchronous clustering theory

Stiffness identification of bridge by using the dynamic response of a passing dual axle vehicle based on synchronous clustering theory

Mechanics-informed transformer-GCN for structural dynamic response prediction

Mechanics-informed transformer-GCN for structural dynamic response prediction

Exploring the dynamic responses of group 3 innate lymphoid cells at different times in response to LPS challenge.

Group 3 innate lymphoid cells (ILC3s) have clear roles in regulating mucosal immunity and tissue homeostasis in the intestine, though the immunological functions in lungs remain unclear. This study aimed to demonstrate the dynamic responses of ILC3s to acute inflammation upon LPS challenge. Microarray data and single-cell RNA sequencing (scRNA-seq) data obtained from the GEO database were combined to analyze the function of ILC3 subset, confirmed by flow cytometry assay and qRT-PCR. The gene enrichment analysis of intersected genes identified between microarray data in bacterial pneumonia and single-cell RNA sequencing of intestinal ILC3s were closely related to TNF-alpha effects on cytokine activity, cell motility and apoptosis pathway, indicating the possibility of intestinal ILC3s migration to the lung. Furthermore, the cellular landscapes of ILC3s in lung and intestine at different times after pulmonary infection exhibited varied ILC3 statuses. ILC3s in lung expanded a lot at 48h while intestinal ILC3s decreased at 72h response to LPS challenge, with higher expression of marked genes related to TNF-alpha effects on cytokine activity, cell motility and apoptosis pathway. The main findings in our study may serve as valuable resources for understanding the roles that ILC3s play upon LPS challenge, which may offer opportunities for translating ILC3s as therapeutic targets to regulate LPS-induced pulmonary inflammation.