Response Characteristics Research Articles

Vibration characterisation of electric-vehicle electric drivetrain system under electromagnetic excitation and mechanical excitation coupling action

Electromagnetic and mechanical excitation are the main causes of electric drivetrain system (EDS) vibration. In this study, the vibration characteristics of an electric drivetrain assembly under electromagnetic-mechanical excitation coupling were investigated using a three-in-one EDS as the research object. A rigid-flexible coupling dynamic model of the EDS was developed to comprehensively analyse the electric motor, drivetrain, controller housing and bearings. Based on this, a finite-element model of a permanent magnet synchronous motor (PMSM) was developed to analyse the electromagnetic excitation in the EDS. Finally, the vibration response characteristics of different parts of the shaft system, bearing and housing of the EDS under electromagnetic-mechanical excitation coupling were analysed. The results indicated that the 24th and 48th-order electromagnetic excitations of the motor contributed considerably to the vibration of the system and that, with regard to mechanical excitation, the first-stage gear pair had a stronger impact on the system than the second-stage gear pair. The vibration response of the shaft system decreased in the following order: intermediate shaft > input shaft > output shaft > rotor shaft. The vibration state of each shaft bearing was consistent with that of the corresponding shaft system; on the assembly housing, the vibration was largest at the connection between the motor housing and the reducer housing. The findings of this study provide guidance for EDS noise, vibration and harshness (NVH) performance analysis and structural optimisation.

Numerical Simulation of Resistivity Response Characteristics in Seepage Detection of Cutoff Walls Using Cross-Hole Resistivity Tomography

Numerical Simulation of Resistivity Response Characteristics in Seepage Detection of Cutoff Walls Using Cross-Hole Resistivity Tomography

Gafchromic Films as a Complementary In-field Dosimetric Tool to Monitor Low Photon Radiation Doses (≤50 mSv).

This study elucidated the radiation response characteristics of a Gafchromic radiochromic film subjected to low photon doses of ≤50 mSv, which corresponds to the annual whole body effective dose limit for radiation workers in Canada. Radiochromic films are investigated for possible use as a complementary tool for the Canadian Armed Forces that can be worn in addition to their existing personal dosimetry to quickly assess personal radiation dose received from radiological hazards without reliance on electronics. The films were exposed to varying photon energies emanating from x-ray generators and radioisotopes, specifically cesium-137, cobalt-60, and americium-241. The resultant radiation-induced film darkening was quantitatively assessed employing three analytical methodologies: net optical density analysis, UV/Visible spectroscopic analysis, and Fourier Transform Infrared spectroscopic analysis. Ideally, a film dosimeter necessitates a pronounced chromatic alteration and the capability to accurately quantify doses ≤50 mSv where net optical density analysis was identified as the optimal modality for interpreting the film darkening into a dose approximation. This new approach established a lower detection threshold of 7.6 mSv for the films when exposed to cesium-137 radiation. Notably, the film exhibited a linear dose response relationship in terms of net optical density; however, a photon energy-dependent variability was observed within the 0-100 mSv dose range. In conclusion, these Gafchromic radiochromic films present a promising candidate for military dosimetry applications. They offer a real-time, visual dose response that can be discerned by military personnel or analyzed using mobile spectroscopic instrumentation. Moreover, these films demonstrate proficiency in the accurate quantification of photon doses ≤50 mSv. Future investigations will evaluate the film's performance under heterogeneous and indeterminate radiation environments, as well as the impact of environmental conditions on the film's performance.

Structurally Transformable and Reconfigurable Hydrogel-Based Mechanical Metamaterials and Their Application in Biomedical Stents.

Mechanical metamaterials exhibit several unusual mechanical properties, such as a negative Poisson's ratio, which impart additional capabilities to materials. Recently, hydrogels have emerged as exceptional candidates for fabricating mechanical metamaterials that offer enhanced functionality and expanded applications due to their unique responsive characteristics. However, the adaptability of these metamaterials remains constrained and underutilized, as they lack integration of the hydrogels' soft and responsive characteristics with the metamaterial design. Here, we propose structurally transformable and reconfigurable hydrogel-based mechanical metamaterials through three-dimensional (3D) printing of lattice structures composed of multishape-memory poly(acrylic acid)-chitosan hydrogels. By incorporating reversible shape-memory mechanisms that control the structural arrangements of the lattice, these metamaterials can exhibit transformable and reconfigurable mechanical characteristics under various environmental conditions, including auxetic behavior, with Poisson's ratios switchable from negative to zero or positive. These adaptable mechanical responses across different states arise from structural changes in lattice, surpassing the gradual changes observed in conventional stimuli-responsive materials. The application of these metamaterials in multimode biomedical stents demonstrates their adaptability in practical settings, allowing them to transition between expandable, nonexpandable, and shrinkable states, with corresponding Poisson's ratios. By integrating multishape-memory soft materials with metamaterial design, we can significantly enhance their functionality, advancing the development of smart biomaterials.

Investigation of Response Characteristics and Reaction Mechanisms in Nanonickel Doped Sodium Alginate/Graphene Oxide Artificial Muscles.

To address the shortcomings of traditional actuators, such as large size, high energy consumption, and slow response, this study developed a conductive and responsive artificial muscle, exploring the operational principles and performance enhancement techniques for artificial muscles made from sodium alginate and graphene oxide. Initially, the research outlined a preparation methodology using sodium alginate, graphene oxide, and nanonickel as primary materials. Subsequent adjustments in the nanonickel content optimized critical performance metrics, including output force, lifespan, and deflection displacement. Furthermore, the electrochemical properties of the artificial muscle were methodically assessed by utilizing an electrochemical workstation. Comprehensive examinations of surface and internal microstructures, as well as reaction mechanisms, were conducted through scanning electron microscopy and X-ray diffraction analysis. The findings demonstrated that nanonickel supplementation markedly improved the responsiveness and electrochemical properties of the artificial muscle under electrical stimulation, underscoring its substantial promise in biohydrogels and biomimetic technology applications.

Response characteristics and particle contributions of epoxy resin composite embedded with Al particles under different loading modes

Response characteristics and particle contributions of epoxy resin composite embedded with Al particles under different loading modes

Response Characteristics and Regulation Feasibility of DC Charging Station Controlled by GFM/GFL Virtual Inertia for Grid Frequency Stability

Response Characteristics and Regulation Feasibility of DC Charging Station Controlled by GFM/GFL Virtual Inertia for Grid Frequency Stability

Experimental study on multifractal characteristics of acoustic emission response and precursor information identification of gas-bearing coal under load

Experimental study on multifractal characteristics of acoustic emission response and precursor information identification of gas-bearing coal under load

Toward Ultrafast Response and Recovery Characteristics Through ZnO Multilayer Thin Films in Surface Acoustic Wave UV Sensor

Toward Ultrafast Response and Recovery Characteristics Through ZnO Multilayer Thin Films in Surface Acoustic Wave UV Sensor

Low-velocity impact behaviors of TFMLs in hydrothermal and thermal-cycling environments

Thermoplastic fiber metal laminates (TFMLs) have garnered significant attention due to their excellent impact resistance. However, the influence of practical environmental factors on the impact resistance of TFMLs remains inadequately explored. This study endeavor to investigate the impact behaviors and damage tolerance of TFMLs, employing a novel thermoplastic resin, Elium®188, under two simulated marine environments: a thermal-cycling condition (involving 90 days of exposure to 70℃ for 6 h followed by 18 h at room temperature daily) and a hydrothermal environment (consisting of 90 days of immersion in distilled water at 70℃). The impact response and damage characteristics were analyzed through low-velocity impact (LVI) and compression-after-impact (CAI) tests. The findings indicated that under thermal-cycling, the LVI resistance decreased as a result of resin aging, but the resin hardened during aging led to a 48 % increase in CAI strength over the 90-day period. In the hydrothermal environment, the absorbed energy decreased by 5.6 % and CAI strength decreased by 13.7 % after 90 days, primarily due to resin hydrolysis and erosion of the TFMLs’ internal structure by water molecules. This research offers valuable insights into the impact resistance and damage tolerance of TFMLs, serving as a vital reference for practical applications in marine settings.

A study of fast response characteristics for respiratory state identification technology

A study of fast response characteristics for respiratory state identification technology

Research and experimental verification of transverse vibration response characteristics of an axially compressed cantilever beam with concentrated mass at free end

Research and experimental verification of transverse vibration response characteristics of an axially compressed cantilever beam with concentrated mass at free end

Elevated methylmercury production in seasonally inundated sediments: Insights from DOM molecular composition.

Seasonally inundated areas (SIA) within aquatic systems are characterized by elevated methylmercury (MeHg) production. Nevertheless, the response characteristics of dissolved organic matter (DOM) quality in SIA sediments, including its molecular compositions and structure, and their impacts on the MeHg production are not yet fully understood. This research gap has been addressed through field investigations and microcosm experiments conducted in a metal-polluted plateau wetland. The results revealed that DOMSIA had lower levels of chromophoric DOM concentrations, protein-like fractions, molecular complexity, and debris size while exhibiting higher humic-like fractions, molecular weight, COO- groups, and bioavailability than DOM in permanently inundated areas (PIA). Compared with DOMPIA, DOMSIA was more easily biodegraded, and exhibited a higher adsorption capacity while lower binding affinity for Hg(Ⅱ). Moreover, MeHg synthesis by Desulfomicrobium escambiense was 29.6-fold higher in DOMSIA than that in DOMPIA, and DOMSIA amendment also resulted in a higher MeHg production in the sediment. The PLS-PM model demonstrated that DOM compositions positively showed high contributions to MeHg levels in sediment porewater (0.51), while binding affinity had a negative pattern (-0.83), but adsorption capacity had a lower contribution (0.09). These findings provide an updated explanation for the elevated MeHg level in the SIA of aquatic systems, which are closely related to the adaptive response of DOM molecular composition and structure in the sediment.

Simulation of dynamic response changes in curved river flow under landslide-induced surge wave influence

This article uses a three-dimensional loose rock landslide surge model test in shallow water areas under dynamic water conditions to study the dynamic response characteristics of river flow. Based on the observation of the changes in the flow field and morphology of the river surface before and after the landslide body enters the water using a large-scale surface flow field measurement system, the changes in the river flow conditions under the influence of landslide surges are divided into four main stages: normal water flow state, landslide inflow disturbance state, wave current coupling motion state, and accumulation body ejection state. According to the acoustic Doppler velocimeter flowmeter arranged at the intersection of the initial surge waveform centerline and the mainstream flow direction, the three-dimensional velocity time-domain process near the water surface is measured and analyzed. Based on different cross sections and measuring points in the landslide area and its upstream and downstream, a non-steady flow propeller flowmeter and an ultrasonic wave/water level acquisition analyzer were arranged to measure and reveal the longitudinal and transverse flow velocity distribution and water surface line variation of the river under the influence of landslide surge.

Design of tuned mass damper for the electric reactor based on finite element method

AbstractThe reliable operation of the electric reactor is critical for ensuring energy transmission in the power system. Vibration is an important influencing factor. This study focused on the vibration response characteristics of the electric reactor during the operation process. The vibration at the measuring points on four side surfaces and the top of the oil tank is measured and analysed by applying the rated voltage at the rated frequency on the reactor. The frequency corresponding to the maximum vibration amplitude at the measuring point between the reinforced iron on the side surface of the reactor is determined. The tuned mass damper (TMD) is designed and the material is prepared. The specific frequency tuning mechanism is designed to suppress the reactor's vibration. The damper's optimal structural size is determined based on finite element method according to modal analysis results. According to the simulation results, the designed TMD can provide an inertia force at the target frequency for the controlled structure along the opposite direction, significantly reducing the electric reactor's vibration amplitude and effectively suppressing the vibration at a single frequency. In addition, static analysis and model strength checks are also conducted to ensure the damper's stability and safety in actual applications.

Analysis of vibration response characteristics of subway station and superstructure with hard combination

Analysis of vibration response characteristics of subway station and superstructure with hard combination

Smartphone-assisted colorimetry and array test strip integrated platform for urine multi-index simultaneous precise quantification and personalized healthcare monitoring

As a non-invasive monitoring method, urine analysis is one of the “three routines” of medical examination, which is of great significance for the early diagnosis, therapeutic effect judgment and long-term fine monitoring of chronic diseases such as metabolic system diseases and kidney diseases. It is imperative to develop a home urine routine detection system. In this paper, Smart Urine Analyzer is innovatively developed by combining smartphones with array urine dipsticks, and equipped with the unique design of adjustable bracket suitable for camera position of different smartphones. The optimal colorimetric value was selected for analysis based on chromogenic response characteristics combined with digital image colorimetry, and the breakthrough from qualitative semi-quantification to precise quantification of 9 kinds of urine biomarkers was completed. And a smartphone App for automated image recognition and processing was developed, which was applied for at-home routine healthcare. 100 clinical urine samples were used to evaluate the reliability of the system. Among them, the ROC curve showed a high consistency between Smart Urine Analyzer and the Dirui H-800 urine analyzer in hospital, which further verified the practicability. As a result, the user-friendly Smart Urine Analyzer can share health data and condition with doctors in real time, which provides a new scheme and means for the home detection of urine biomarkers, and has great practical application value as a potential home medical service assistant.

The dynamic response characteristics of “ChangJiangKou II” shipwreck salvaging operation: Physical and numerical experiments

The dynamic response characteristics of “ChangJiangKou II” shipwreck salvaging operation: Physical and numerical experiments

Walnut shell-based composite fillers to enhance two-stage biological aerated filter for efficient nitrogen removal: carbon source slow-release properties, regulatory strategies and microbial response characteristics

Walnut shell-based composite fillers to enhance two-stage biological aerated filter for efficient nitrogen removal: carbon source slow-release properties, regulatory strategies and microbial response characteristics

Analysis of Structural Characteristics of the HALE Joined‐Wing Configuration UAV

This study focuses on a high‐altitude long‐endurance (HALE) joined‐wing configuration UAV and completes a preliminary structural design based on aircraft design indices and the fundamental principles of aircraft structure design. Based on the preliminary structural design scheme and aerodynamic shape, a structural finite element model and a vortex lattice aerodynamic analysis model of the UAV are established, and the aerodynamic loads in typical states are obtained. The aerodynamic loads of the UAV are applied to a finite element model using the multipoint row method, and the structural static characteristics are obtained. The study further explores typical structural dynamic characteristics, including natural mode, static aeroelastic, flutter, and gust response characteristics. A comparison with the structural characteristics of a conventional configuration UAV with the same structural weight reveals that the HALE joined‐wing configuration UAV exhibits significant advantages in structural stiffness, mode characteristics, flutter characteristics, and static aeroelastic characteristics, whereas the gust response characteristics are essentially equivalent to those of the conventional configuration. This superiority can be attributed to the reduced wingspan while providing the same lift and effective support effect of the rear wing on the front (Frt) wings, which enhances the structural stiffness of high‐aspect‐ratio HALE UAVs. This configuration is particularly suitable for deployment in high‐subsonic HALE configurations that require close coordination with conventional tactical aircraft. By comparing with the structural characteristics of the conventional configuration UAV with equal structural weight, the paper comprehensively analyzes the structural characteristics of the HALE joined‐wing configuration and obtains the advantages and disadvantages of applying the joined‐wing configuration in HALE aircraft and defines the design direction, which lays a solid foundation for the engineering application in the next stage.