A New Magneticrheological Damper Nonlinear Bingham Hysteretic Model and ANSYS Implementation

2013 ◽  
Vol 351-352 ◽  
pp. 1146-1151 ◽  
Author(s):  
Zheng Xin Zhang ◽  
Fang Lin Huang
Keyword(s):  
Mechanical Model ◽  
Least Square Method ◽  
Least Square ◽  
Test Results ◽  
Hysteretic Model ◽  
Damping Force ◽  
Damping Characteristics ◽  
Magneto Rheological ◽  
The Relationship ◽  
Force Characteristics

In this paper, firstly, a new nonlinear Bingham hysteretic model is established by studying on the Test results of damping force characteristics of the magneto rheological fluid. The model not only can simulate the damping characteristics of the magneto rheological damper very well, but also can well describe the relationship between damping and velocity with the small velocity, and has fewer parameters by compared with other magneto rheological damper model. Secondly, based on nonlinear least square method, the parameters with different current are recognized and the relationship between the parameters and current is defined, then the mechanical model is theoretically verified. Furthermore, the mechanical model is simulated by ANSYS, the data obtained agree well with the calculated value.

Damping characteristics of a magneto-rheological damper with dual independent controllable ducts

2021 ◽  
pp. 1045389X2110188
Author(s):  
Jianqiang Yu ◽  
Xiaomin Dong ◽  
Tao Wang ◽  
Zhengmu Zhou ◽  
Yaqin Zhou
Keyword(s):  
Dynamic Range ◽  
Fluid Flows ◽  
Mr Damper ◽  
Viscous Damping ◽  
The Novel ◽  
The Finite Element Method ◽  
Damping Force ◽  
Damping Characteristics ◽  
Magneto Rheological ◽  
The Mathematical Model

This paper presents the damping characteristics of a linear magneto-rheological (MR) damper with dual controllable ducts based on numerical and experimental analysis. The novel MR damper consisting of a dual-rod cylinder system and a MR valve is used to reduce the influences of viscous damping force and improve dynamic range. Driven by the dual-rod cylinder system, MR fluid flows in the MR valve. The pressure drop of the MR valve with dual independent controllable ducts can be controlled by tuning the current of two independent coils. Based on the mathematical model and the finite element method, the damping characteristics of the MR damper is simulated. A prototype is designed and tested on MTS machine to evaluate its damping characteristics. The results show that the working states and damping force of the MR damper can be controlled by the two independent coils.

Approximation of the Kinematics of Foot Joints by Using Passive Elastic Characteristics of Joint

2007 ◽  
Vol 342-343 ◽  
pp. 621-624
Author(s):  
Hyeon Ki Choi ◽  
Si Yeol Kim ◽  
Won Hak Cho
Keyword(s):  
Joint Angle ◽  
Reaction Force ◽  
Force Plate ◽  
Least Square Method ◽  
Least Square ◽  
Biomechanical Analysis ◽  
Clinical Evaluations ◽  
Foot Joints ◽  
The Relationship ◽  
Elastic Characteristics

We investigated the relationship between kinematic and kinetic characteristics of foot joints resisting ground reaction force (GRF). Passive elastic characteristics of joint were obtained from the experiment using three cameras and one force plate. The relationship between joint angle and moment was mathematically modeled by using least square method. The calculated ranges of motion were 7o for TM joint, 4o for TT joint and 20o for MP joint. With the model that relates joint angle and plantar pressure, we could get the kinematic data of the joints which are not available from conventional motion analysis. The model can be used not only for biomechanical analysis which simulates gait but also for the clinical evaluations.

Parameters Identification for Nonlinear Duffing System Based on Wavelet Transformation

2013 ◽  
Vol 357-360 ◽  
pp. 1524-1530
Author(s):  
Shi Zhou ◽  
Dong Mei Huang ◽  
Wei Xin Ren ◽  
Qiong Li Wang
Keyword(s):  
Forced Vibration ◽  
Wavelet Transformation ◽  
Recognition Accuracy ◽  
Vibration Signal ◽  
Least Square Method ◽  
Least Square ◽  
Instantaneous Amplitude ◽  
Approximate Analytical Expression ◽  
Duffing System ◽  
The Relationship

Continuous wavelet transformation is made to identify the parameters of damped harmonic forced vibration Duffing system. With the aid of conversion relationship between the scale and frequency, the solution of nonlinear Duffing equation is adopted by average method, which gained approximate analytical expression for instantaneous amplitude and instantaneous frequency of the system. The nonlinear stiffness coefficient and natural frequency can be gained by least square method and the relationship between recognition accuracy and parameter selection are summarized in the article. Parameter identification method of harmonic forced vibration system is proposed in this paper. Studying the wavelet ridge and corresponding scale by segments to filter out the affects of the simple harmonic motion, to extract systems free vibration signal and to achieve the goal of identifying system parameters.

scholarly journals A Study on the Relationship between Earnings Quality and Capital Cost-Takes the China Listed Companies as a Sample

2021 ◽  
pp. 48-56
Author(s):  
Chih-Yi Hsiao ◽  
Hui-Hui Kuang ◽  
Hui-Ling Li ◽  
Jia-Li Liu
Keyword(s):  
Earnings Management ◽  
Earnings Quality ◽  
Least Square Method ◽  
Listed Companies ◽  
Capital Cost ◽  
Least Square ◽  
Accounting System ◽  
Ordinary Least Square ◽  
Research Findings ◽  
The Relationship

The phenomenon of false financial statements still exists. However, in addition to the risk of being punished, what kind of price do companies have to pay? In recent decades, with China's rapid progress in economic, the relevant accounting system and corporate governance standards are actively improving, and the earnings quality is improving. This paper takes China's listed companies from 2015 to 2019 as samples, and adopts quantile regression supplemented by ordinary least square method to explore the relationship between earnings quality and capital cost. The research findings show that the higher the earnings management, the higher the capital cost, especially for the company with low capital cost. Nevertheless, for the extremely company with high capital cost, earnings management can reduce the capital cost. The research results can provide the focus of regulators of listed companies and reference for the revision of relevant accounting system.

scholarly journals Energy Dissipation Characteristics and Parameter Identification of Symmetrically Coated Damping Structure of Pipelines under Different Temperature Environment

Symmetry ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1283
Author(s):  
Feng Jiang ◽  
Zheyu Ding ◽  
Yiwan Wu ◽  
Hongbai Bai ◽  
Yichuan Shao ◽  
...  
Keyword(s):  
Energy Dissipation ◽  
Hysteresis Loop ◽  
Least Square Method ◽  
Least Square ◽  
Test Results ◽  
Restoring Force ◽  
Dissipation Model ◽  
Effects Of Temperature ◽  
Dissipation Test ◽  
Metal Wires

In this paper, a symmetrically coated damping structure for entangled metallic wire materials (EMWM) of pipelines was designed to reduce the vibration of high temperature (300 °C) pipeline. A series of energy dissipation tests were carried out on the symmetrically coated damping structure at 20–300 °C. Based on the energy dissipation test results, the hysteresis loop was drawn. The effects of temperature, vibration amplitude, frequency, and density of EMWM on the energy dissipation characteristics of coated damping structures were investigated. A nonlinear energy dissipation model of the symmetrically coated damping structure with temperature parameters was established through the accurate decomposition of the hysteresis loop. The parameters of the nonlinear model were identified by the least square method. The energy dissipation test results show that the symmetrically coated damping structure for EMWM of pipelines had excellent and stable damping properties, and the established model could well describe the changing law of the restoring force and displacement of the symmetrically coated damping structure with amplitude, frequency, density, and ambient temperature. It is possible to reduce the vibration of pipelines in a wider temperature range by replacing different metal wires.

Magneto-Rheological (MR) Damper Design for High-Flowrate Suspensions

2013 ◽  
Author(s):  
Riaan F. Meeser ◽  
P. Schalk Els ◽  
Sudhir Kaul
Keyword(s):  
Mr Damper ◽  
Damping Force ◽  
Mr Fluid ◽  
Bingham Plastic ◽  
Damping Characteristics ◽  
Final Design ◽  
Variable Damping ◽  
Input Variables ◽  
Damper Design ◽  
Magneto Rheological

This paper presents the design of a magneto-rheological (MR) damper for an off-road vehicle where large suspension travel and high flow rates, as compared to typical passenger car suspensions, are required. The MR damper is expected to enhance the capability of the suspension system by allowing variable damping due to inherent properties of the MR fluid. MR fluids exhibit a reversible behavior that can be controlled with the intensity of a magnetic field, allowing a change in the effective viscosity and thereby in the damping characteristics of the fluid. A mathematical model of the proposed damper has been developed using the Bingham plastic model so as to determine the necessary geometry for the damper designed in this study, using the fluid flow rate and current to the electromagnet as the input variables. The model is used to compute the damping force, and the analytical results show that the designed MR damper provides the required range of damping force for the specific vehicle setup that is being used for this study. A valve-mode MR fluid channel has been designed such that the required minimum damping is reached in the off-state, and the desired maximum damping is reached in the on-state. For manufacturing and size considerations, the final design incorporates a triple pass layout with the MR fluid flowing through the three passages that are arranged in an S-shape so as to minimize the cross section of the electromagnet core.

An Identification Method of Failure Mechanism Consistency for Rubber Materials in Accelerated Aging Testing

2016 ◽  
Vol 723 ◽  
pp. 237-241
Author(s):  
Han Zhang ◽  
Yue Li ◽  
Ya Shun Wang
Keyword(s):  
Activation Energy ◽  
Failure Mechanism ◽  
Accelerated Aging ◽  
Least Square Method ◽  
Least Square ◽  
Arrhenius Model ◽  
Rubber Material ◽  
Velocity Constant ◽  
Identification Method ◽  
The Relationship

The failure mechanism of rubber materials under accelerated stress in aging process may be different from that under normal conditions. Therefore, identification of the failure mechanism consistency is necessary for the accelerated aging testing of rubber material. To solve the problem, we study the relationship between the aging velocity of permanent compression set value and aging time. Firstly, according to the relationship, the aging velocity constant is obtained through the least square method. Then, combining with the aging velocity constant, we found that the activation energy is equal to the slope of linear function about Arrhenius model. Based on that failure activation energy keeps same under same failure mechanism, an identification method about failure mechanism consistency is developed. Finally, to demonstrate and validate the proposed method, we take the accelerated aging testing for the nitrile rubber-26 sealing gasket as an example.

Research of Binocular Positioning Mathematical Model Based on the Least Square Method

2011 ◽  
Vol 50-51 ◽  
pp. 473-477 ◽  
Author(s):  
Chun Feng Liu ◽  
Xiao Li Meng ◽  
Huan Cheng Zhang
Keyword(s):  
Relative Position ◽  
Three Dimensional ◽  
Digital Camera ◽  
Least Square Method ◽  
Absolute Error ◽  
Least Square ◽  
Specific Data ◽  
Centroid Algorithm ◽  
Three Dimensional Coordinate ◽  
The Relationship

By giving a centroid algorithm to extract pixel coordinates of each circle in the center of a circle under the coordinates, through the coordinate transformation the image coordinates can be obtained. Based on the data obtained from above to verify the model, from the specific data of the relative error, absolute error and error propagation theory to discuss the algorithm accuracy and stability. Finally using the least square method, according to the mean square error criteria for the establishment of a minimum of three-dimensional coordinate system fixed relative position of two cameras, binocular positioning mathematical models and by discussing the nature of matrix and the relationship between the relative position of the camera to calibrate the binocular digital camera.

The relationship between immigration and tourism firms

2017 ◽  
Vol 23 (8) ◽  
pp. 1537-1552 ◽  
Author(s):  
Carla Massidda ◽  
Ivan Etzo ◽  
Romano Piras
Keyword(s):  
Positive Relationship ◽  
Least Square Method ◽  
Least Square ◽  
Estimation Technique ◽  
Two Stage ◽  
The Relationship

This article investigates whether the presence of immigrants represents an opportunity for Italian tourism firms to increase the number of establishments and their employees. To this scope, we focus on the hotels and restaurants sector where a great amount of revenues comes from the tourist expenditure. The investigation is conducted at both the nationwide level and, separately, for Centre-Northern and Southern provinces. As estimation technique, in order to deal with the potential endogeneity problem, we will proceed with the two-stage least square method. The results strongly support a positive relationship between the provincial share of immigrants and the number of tourism establishments and their employees. This relationship seems to be stronger for southern provinces.

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