Influence Of Suspension Parameters Research Articles

Electrophoretic deposition of hydroxyapatite Coating: A state of art

Hydroxyapatite (HA) is the most widely used bioceramic for different biomedical applications due to its superior bioactivity, biocompatibility, osteointegration properties. It can be employed as the bulk material or coating on metallic substrate. Electrophoretic deposition (EPD) of HA itself and also with combination of other materials, is demanding more recognition for biomedical use such as repair and replacement of dental implant, knee implant and hip replacement. The current study elaborates an extensive review on the field of EPD of HA coating and HA-based composite coating. This study highlights the preparation and applications of HA. The process parameters have the significant effect on the deposition physics and mechanisms and on the overall properties of EPD coatings. Hence, in this study, the influence of suspension parameters like concentration, composition, process parameters like voltage, time on deposition mechanism are elaborated. In addition, the structural, mechanical as well as biological properties of HA and HA-based composite coating are clearly described in this study.

Suspension Parameters Optimization of HTS Maglev Under Random Vibration

The world's first high temperature superconducting(HTS)magnetic levitation (maglev) engineering prototype vehicle and test line were officially put into use at Southwest Jiaotong University, China, on January 13 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sup> , 2021. This event means that HTS maglev has now made the leap in the engineering research. The influence of the suspension parameters on the random vibration of vehicle is an important content in dynamic optimization, which will affect the operation stationarity. In this paper, we investigated the random vibration of HTS maglev prototype by numerical simulation and optimized the suspension parameters to obtain a good operation quality. Firstly, a dynamic model of the HTS maglev engineering vehicle was established based on UM software. Secondly, the influence of suspension parameters and operation speed on vehicle operation stationarity were studied. Finally, simulation results were discussed in detail based on a set of selected suspension parameters. Results show that the suspension parameters and operating speed have obvious effects on the vehicle stationarity, and the reasonable selection of the secondary suspension parameters can ensure the stable operation of the HTS maglev at a maximum speed of 620 km/h.

Experiments and Simulations of the Secondary Suspension System to Improve the Dynamic Characteristics of HTS Maglev

High temperature superconducting (HTS) magnetic levitation (maglev) has the potential as a high-speed passenger transportation mode owing to its passive stabilization. Our group is constructing a 1500 m-long HTS maglev high speed test line. As a kind of passenger transport, safety and comfort are primary factors for its operation quality. However, the weak damping in HTS maglev system is not enough to suppress the vibration. As a preliminary study of the test line, this article investigates an additional suspension system aiming to improve the dynamic characteristics of HTS maglev through experiments and simulation. We first built an HTS maglev model vehicle composed of a levitation frame and a car body. The dynamic responses were tested based on a dynamic measurement system. Second, a dynamic model of this kind of maglev device was established and the influence of suspension parameters on its vibration performance is analyzed theoretically. Third, this suspension system was applied to an HTS maglev engineering prototype through numerical simulations. Experimental and simulation results manifested that the suspension system can effectively reduce the vibration, especially with high frequencies. This article provides a reference for the design of HTS maglev vehicles.

Alternating Current Electrophoretic Deposition of Chitosan-Gelatin-Bioactive Glass on Mg-Si-Sr Alloy for Corrosion Protection.

Magnesium alloys have gained significant attention as degradable implant materials, but the fast and localized corrosion behavior leading to hydrogen gas evolution and alkaline poisoning limits their clinical application. In this research, the possibility of controlling the fast degradation rate of an experimental Mg-Si-Sr alloy by applying hybrid biopolymer chitosan (CS)-gelatin (G)-bioactive glass (BG) coatings was investigated. Electrophoretic deposition using alternating current fields (AC-EPD) was employed for surface coating and the influence of suspension parameters (biopolymer type and concentration, BG particle size), and key AC-EPD parameters (voltage amplitude, frequency, and time) on the coating quality were investigated. Stable suspensions of positively charged biopolymer/BG particles deposited on the Mg alloy coupled as a cathode during the high-amplitude peak. Furthermore, coating homogeneity improved with increasing peak-to-peak-voltage and the hybrid nature of the coatings was confirmed by scanning electron microscopy and Fourier transform infrared spectroscopy. Corrosion studies revealed a significantly decreased corrosion rate down to 0.08 mm/year for the Mg-Si-Sr alloy incorporating CS-G-BG b AC-EPD coating.

Research on ride comfort analysis and hierarchical optimization of heavy vehicles with coupled nonlinear dynamics of suspension

The fact that the calculation model and optimization method are critical to the optimization efficiency of ride comfort. To improve the reliability of this process for heavy vehicles, this article proposes a systematic modelling method that is based on the coupled nonlinear dynamics of suspension components and a hierarchical optimization method that considers passenger comfort, cargo safety, and parts fatigue. Nonlinear mathematical models of leaf springs and dampers are established first. A novel model of ride comfort is then developed by integrating the nonlinear mathematical models with a conventional vibration model formulated according to Newton's second law. According to experimental observations, the novel model shows greater accuracy than the conventional one. Subsequently, the influences of suspension parameters on ride comfort are clarified with an integrated multi-software method, illustrating steering suspension stiffness and cabin rear suspension damping are significant factors affecting ride comfort. Finally, a hierarchical optimization model is developed to enhance ride comfort and minimize the amplitude of vibrations. The optimized vibrations show average reductions of 31.1% and 17.0% for the seat rail and sprung centroid, respectively.

Wall Slip Effect in Couette Rheometers

Wall slip of suspensions in confined flow is caused by segregation of a thin layer of liquid phase adjacent to the walls. This causes the bulk phase to slide along the walls, which means that the fluid flow velocities respective to the walls are not zero. In rheometers this affects the evaluation of the rheological properties. Despite the importance of understanding and controlling segregation effects, little research has been done on this subject area. Indeed in industrial casting, the die filling behaviour, and therefore the product quality, may depend on the segregation phenomena. It is important to understand the wall slip phenomenon’s correlation with experimental parameters, as a step towards casting process optimization. Two issues are handled in the present work, the first is the evaluation of different methods to investigate the wall slip effect, the second is the investigation of the wall slip effect dependency on the suspension parameters particle size and solid fraction, respectively. The suspensions employed for the investigations were the aluminium alloy A356 in semi-solid form and a “synthetic suspension” built up of glass spheres in silicon oil. As a result of the above described investigations, influence of suspension parameters are found, and a validated method to avoid the wall slip effect is suggested.

Hydro-gas suspension system for a tracked vehicle: Modeling and analysis

Tracked vehicles fitted with torsion bar suspensions are limited in their ability to achieve high mobility. This limitation is due to the linear characteristics and the consequent poorer ride performance. Hydro-gas suspensions due to their inherent non-linear behavior can provide higher mobility and better ride comfort performance. The hydro-gas suspension model has usually been developed from experimental force–displacement characteristics, which requires availability of suspension hardware. In this paper, a hydro-gas suspension system is modeled using polytropic gas compression model to represent the spring characteristics, while the damper orifices are modeled using hydraulic conductance. The analytical model is then validated with experiments individually for spring and damper flow characteristics and then as a suspension-wheel assembly in a test rig. The validated suspension model is incorporated in an in-plane model. Using this model, simulation is carried out for sinusoidal inputs of different wavelengths, amplitudes and vehicle speeds. The simulation model is validated with data measured on a vehicle traversing an APG course. The proposed model agrees very well with the measured data. Based on the validated model, studies on the influence of suspension parameters on the ride comfort of a tracked vehicle are carried out.

Application of Linear Switched Reluctance Motor for Active Suspension System in Electric Vehicle

Electromagnetic active suspension system is considered to have improved stability and better dynamic response, compared to the hydraulic active suspension system. To investigate the influence of suspension parameters on system characteristics, the frequency response of quarter vehicle model is analyzed through Bode plots by varying the spring stiffness and damping coefficient. The sprung mass acceleration, suspension deflection and tire deflection are investigated respectively. This paper proposes a novel electromagnetic suspension system, comprising of a linear switched reluctance motor (LSRM) and a passive spring. The mechanical and electrical characteristics of the proposed linear motor are obtained and verified by using two-dimensional finite element method (FEM). The magnetic flux densities at specific translator positions are demonstrated. In order to study the feasibility and evaluate the performance of the proposed suspension system, a LQR optimal controller is developed and simulated with the quarter-vehicle model. The sprung mass acceleration, suspension deflection and related force applied by the actuator are investigated under different road disturbance. Both frequencies of disturbance are approximate to the suspension natural frequencies, which are the most severe working point of active suspension system. Simulation results demonstrate that good dynamic response and better ride comfort can be achieved by the proposed active suspension system.

Performances of seed drill coulters in relation to speed, depth and rake angles

The horizontal and vertical soil forces acting on coulters with rake angles of 70, 90, 110 and 130 ° and widths of 15 and 40 mm were measured to investigate the variation of working depth under various conditions. The measurements were made with extended octagonal ring transducers using speeds between 0·3 and 3·0 m/s and depths down to 70 mm both in dry sand in the laboratory and down to 45 mm in a clay field. Polynomials in one variable and in several variables were fitted to the measured data using statistical analysis. The relationship of force to speed was well described by a second-order polynomial. The quadratic term contributed far more to the fit of the model than the linear term. The relationship of force to depth was described by a second-order polynomial, but this polynomial had its intercept at the origin. Polynomials in the three variables rake angle, speed and depth were also fitted. These polynomials were used to investigate the influence of coulter and suspension parameters upon the variation in equilibrium depth when the coulter is subjected to varying working conditions. In sandy soils the variation in equilibrium depth decreased with increasing rake angle, while the influence of the suspension parameters was small.