scholarly journals Thermodynamic Behaviors of a Kind of Self-Decoupling Magnetorheological Damper

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Guojun Yu ◽  
Chengbin Du ◽  
Tiger Sun
Keyword(s):  
Theoretical Model ◽  
Heat Dissipation ◽  
Performance Test ◽  
Design Method ◽  
Constraint Equation ◽  
Magnetorheological Damper ◽  
Design Parameters ◽  
Test Results ◽  
Damping Force ◽  
Conservation Of Energy

A theoretical model of temperature change on a kind of self-decoupling magnetorheological (SDMR) damper was established based on conservation of energy, and the constraint equation for structural design parameters of the SDMR damper was improved to satisfy heat dissipation requirements in this work. According to the theoretical model and improved constraint equation, the main structure parameters of SDMR damper were obtained and the damper was tested. The temperature performance test results indicate that the rising temperature makes the damping force decline, and the main affection factors of temperature variation are excitation methods and input current. The results also show that the improved constraint equation and design method introduced are correct and efficient in the engineering.

Valve Parameters Design and Performance Test of Hydro-Pneumatic Spring with Trapezium Throttle Slice

2008 ◽  
Vol 44-46 ◽  
pp. 409-414
Author(s):  
Chang Cheng Zhou ◽  
Wei Xu
Keyword(s):  
Performance Test ◽  
Design Method ◽  
Design Parameters ◽  
Slice Thickness ◽  
Test Results ◽  
Opening Pressure ◽  
Mechanics Model ◽  
Hole Area ◽  
Valve Opening ◽  
And Performance

With the mechanics model, the analytic formula of the deformation for the trapezium throttle slice was established. By the vehicle parameters and valve opening velocity, the formula of valve opening pressure was built. Based on this, through the relation of pressure with deformation and flux at valve opening, the design formula of throttle slice thickness and throttle-hole area were established, the influencing factors to the design parameters were analyzed. A practical example of design of hydro-pneumatic spring was given, and the performance test was conducted. The analysis and test results show that the design method is effective and the formulas for throttle slice thickness and throttle-hole area are accurate enough, and have important meaning for the hydro-pneumatic spring design.

scholarly journals Design and Analysis of a New Magnetorheological Damper for Generation of Tunable Shock-Wave Profiles

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Jong-Seok Oh ◽  
Tae-Hoon Lee ◽  
Seung-Bok Choi
Keyword(s):  
Shock Wave ◽  
Mr Damper ◽  
Wave Profile ◽  
Impact Testing ◽  
Magnetorheological Damper ◽  
Design Parameters ◽  
Testing System ◽  
Damping Force ◽  
Wave Profiles ◽  
Mass Spring

A new impact testing system with an integrated magnetorheological (MR) damper is proposed, and its dynamic characteristics are analyzed. The testing system consists of a velocity generator, impact mass, test mass, spring, and MR damper. In order to tune the dual shock-wave profile, a dynamic model was constructed, and the appropriate design parameters of the MR damper were then determined to produce the required damping force. Following this, an impact testing system was constructed to evaluate the design analysis and field-dependent dual shock-wave profiles. The experimental results of impact test showed that the dual shock-wave profile can be altered by changing the intensity of the magnetic field.

Analysis and Design of Magnetorheological Damper

2010 ◽  
Vol 148-149 ◽  
pp. 882-886 ◽  
Author(s):  
Jin Huang ◽  
Jian Min He ◽  
Guo Ping Lu
Keyword(s):  
Magnetic Field ◽  
Applied Magnetic Field ◽  
Design Method ◽  
Outer Cylinder ◽  
Magnetorheological Damper ◽  
Effective Length ◽  
Damping Force ◽  
Analysis And Design ◽  
Mr Dampers ◽  
Mr Fluids

Magnetorheological (MR) dampers are the semi-active control devices that use MR fluids to produce controllable dampers. In this paper, the design method of the cylindrical MR damper is established. Bingham model is used to describe the constitutive behavior of MR fluids subject to an applied magnetic field. The equation for the damping force is derived to provide the theoretical foundation for the design of the damper. Based on this equation the engineering expressions for the gap and effective length of the annular MR fluid between the piston and the outer cylinder are derived. The result shows that with the increase of the applied magnetic field strength, the damping force is increased. The dimensions of the gap and length can be calculated when the required damping force, the velocity of the piston, and the desired control damping force ratio are specified.

scholarly journals A Novel Double-Piston Magnetorheological Damper for Space Truss Structures Vibration Suppression

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Qiang Wang ◽  
Mehdi Ahmadian ◽  
Zhaobo Chen
Keyword(s):  
Vibration Suppression ◽  
Maximum Velocity ◽  
Mr Damper ◽  
Magnetorheological Damper ◽  
Truss Structures ◽  
Test Results ◽  
Damping Force ◽  
Space Applications ◽  
Space Truss ◽  
Displacement Force

The design, fabrication, and testing of a new double-piston MR damper for space applications are discussed. The design concept for the damper is described in detail. The electromagnetic analysis of the design and the fabrication of the MR damper are also presented. The design analysis shows that the damper meets the weight and size requirements for being included in a space truss structure. The prototype design is tested in a damper dynamometer. The test results show that the damper can provide nearly 80 N of damping force at its maximum velocity and current. The test results also show that the seal drag could contribute significantly to the damping forces. Additionally, the test results indicate that both the work by the damper and damping force increase rapidly with increasing current at lower currents and taper off at higher currents as the damper starts to saturate. The damper force versus velocity plots show hysteresis in both pre- and postyield regions and asymmetric forces in jounce and rebound. A model is proposed for representing the force-displacement, force-velocity, and asymmetric forces observed in test results. A comparison of the modeling results and test data indicates that the model accurately represents the force characteristics of the damper.

Effects of magnetic core parameters on landing stability and efficiency of magnetorheological damper-based landing gear system

2019 ◽  
Vol 31 (2) ◽  
pp. 198-208 ◽  
Author(s):  
Chulhee Han ◽  
Bo-Gyu Kim ◽  
Byung-Hyuk Kang ◽  
Seung-Bok Choi
Keyword(s):  
Equations Of Motion ◽  
Magnetic Core ◽  
Landing Gear ◽  
Gear System ◽  
Magnetorheological Damper ◽  
Design Parameters ◽  
Damping Force ◽  
Magnetic Circuits ◽  
Aircraft Landing ◽  
New Type

In this research, a new type of magnetorheological damper for a small-sized aircraft landing gear system is proposed and its performance is evaluated with respect to design parameters of the magnetic core. As a first step, a new configuration of magnetorheological damper for the landing gear system, which consists of orifices, recoil valve, and magnetic circuits, is introduced with working principles. After formulating the governing equations of motion, six different models of magnetorheological damper featuring different number of magnetic core and different pole length are chosen to investigate both the landing stability and the efficiency. Subsequently, the distribution of the magnetic field intensity of each model is analyzed through the finite element method, followed by the calculation of the field-dependent damping force to be used for the landing simulation, which is undertaken by adopting the dynamic model of a half airplane landing gear system. In order to identify the significance of the magnetic core parameters, the landing stability is judged from the sign of the minimum force and the landing efficiency is determined from the energy dissipation during the vertical drop motion.

PENGARUH MODEL PEMBELAJARAN KELILING KELOMPOK (ROUND CLUB) TERHADAP KETERAMPILAN MENULIS LAPORAN PERJALANAN SISWA KELAS V SDN 01 NAGARI BUKIK SIKUMPA

2020 ◽  
Author(s):  
Wirda Linda
Keyword(s):  
Standard Deviation ◽  
Performance Test ◽  
Writing Skills ◽  
Learning Model ◽  
Homogeneity Test ◽  
Test Results ◽  
Class V ◽  
Average Value ◽  
Normality Test ◽  
Lecture Method

This research is motivated by the low desire of students in writing travel reports. The lack of students' knowledge of the report concept, the lack of students' knowledge of the 5W + 1H report points of good and correct language, the lack of students' knowledge of the spatial, time and topic pattern and not yet reached KKM 75. The method used by the teacher has not been interesting, lecture method. The purpose of this study is to describe the skills of writing travel reports by using Round Club learning model which is viewed from the aspect of understanding the report concept, the use of 5W +1H report points, the spatial, time, and topic pattern.The population of this study is the students of class V Lessons Year 2017/2018 which amounted to 2 classes with the number 80. The sample of research as much as two classes taken by the sample of propotional.Class V.1 as experimental class and class V.2 as control class. The research instrument used is performance test. Provide an assessment by specifying the subject of the 5W + 1H report, as well as the spatial, time and topic pattern. Data were analyzed by 't' test by first testing normality, homogeneity, and hypothesis testing.The results showed that the average control class 68 with more than enough qualifications with standard deviation 16.96. 83 experimental class with good qualification and standard deviation of 15.42 and there is a significant influence on the result of writing skill of class V SDN 01 Nagari Bukik SikumpaSubdistrict, Lima Puluh Kota. This is evidenced by the average value of writing skills in the experiment class higher than the average value in the control class. Normality test results indicate that the two sample classes of  Lo  values in the control class -0.2141 are smaller than the normal 0.190 Lt distributed. Homogeneity test results that the variation of this study is homogeneous at a real level of 0.05, because Ftable 2.16 > Fhitung 1.21 and the results of data analysis then obtained = 2.78 > 1.70 t table, so H0 rejected and H1 accepted. It can be concluded that there is Influence. Using  Learning  Model of Student Group Writing  Skills Travel Report of students of class V SDN 01 Nagari Bukik Sikumpa Subdistrict, Kabupaten Lima Puluh Kota.KeyWords: model pembelajaran round club, menulis laporan perjalanan.

scholarly journals A modular design method based on TRIZ and AD and its application to cutter changing robot

2021 ◽  
Vol 13 (7) ◽  
pp. 168781402110343
Author(s):  
Mei Yang ◽  
Yimin Xia ◽  
Lianhui Jia ◽  
Dujuan Wang ◽  
Zhiyong Ji
Keyword(s):  
Modular Design ◽  
Design Method ◽  
Idea Generation ◽  
Design Parameters ◽  
Problem Analysis ◽  
Concept Design ◽  
Functional Requirements ◽  
Shield Tunneling ◽  
Structural Hierarchy ◽  
And Performance

Modular design, Axiomatic design (AD) and Theory of inventive problem solving (TRIZ) have been increasingly popularized in concept design of modern mechanical product. Each method has their own advantages and drawbacks. The benefit of modular design is reducing the product design period, and AD has the capability of problem analysis, while TRIZ’s expertise is innovative idea generation. According to the complementarity of these three approaches, an innovative and systematic methodology is proposed to design big complex mechanical system. Firstly, the module partition is executed based on scenario decomposition. Then, the behavior attributes of modules are listed to find the design contradiction, including motion form, spatial constraints, and performance requirements. TRIZ tools are employed to deal with the contradictions between behavior attributes. The decomposition and mapping of functional requirements and design parameters are carried out to construct the structural hierarchy of each module. Then, modules are integrated considering the connections between each other. Finally, the operation steps in application scenario are designed in temporal and spatial dimensions. Design of cutter changing robot for shield tunneling machine is taken as an example to validate the feasibility and effectiveness of the proposed method.

Physical and performance characteristics related to starter status, position, and division in Japanese collegiate American-football players

2021 ◽  
pp. 1-8
Author(s):  
Junta Iguchi ◽  
Minoru Matsunami ◽  
Tatsuya Hojo ◽  
Yoshihiko Fujisawa ◽  
Kenji Kuzuhara ◽  
...  
Keyword(s):  
Performance Test ◽  
Vertical Jump ◽  
American Football ◽  
Football Players ◽  
Jump Height ◽  
Test Results ◽  
Repetition Maximum ◽  
Vertical Jump Height ◽  
Division 1 ◽  
And Performance

BACKGROUND: Few studies have investigated the variations in body composition and performance in Japanese collegiate American-football players. OBJECTIVE: To clarify what characterizes competitors at the highest levels – in the top division or on the starting lineup – we compared players’ body compositions and performance test results. METHODS: This study included 172 players. Each player’s body composition and performance (one-repetition maximum bench press, one-repetition maximum back squat, and vertical jump height) were measured; power was estimated from vertical jump height and body weight. Players were compared according to status (starter vs. non-starter), position (skill vs. linemen), and division (1 vs. 2). Regression analysis was performed to determine characteristics for being a starter. RESULTS: Players in higher divisions and who were starters were stronger and had more power, greater body size, and better performance test results. Players in skill positions were relatively stronger than those in linemen positions. Vertical jump height was a significant predictor of being a starter in Division 1. CONCLUSION: Power and vertical jump may be a deciding factor for playing as a starter or in a higher division.

scholarly journals A Two-Round Optimization Design Method for Aerostatic Spindles Considering the Fluid–Structure Interaction Effect

2021 ◽  
Vol 11 (7) ◽  
pp. 3017
Author(s):  
Qiang Gao ◽  
Siyu Gao ◽  
Lihua Lu ◽  
Min Zhu ◽  
Feihu Zhang
Keyword(s):  
Optimal Design ◽  
Optimization Design ◽  
Design Method ◽  
Fluid Structure Interaction ◽  
Design Procedure ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Aerostatic Spindle

The fluid–structure interaction (FSI) effect has a significant impact on the static and dynamic performance of aerostatic spindles, which should be fully considered when developing a new product. To enhance the overall performance of aerostatic spindles, a two-round optimization design method for aerostatic spindles considering the FSI effect is proposed in this article. An aerostatic spindle is optimized to elaborate the design procedure of the proposed method. In the first-round design, the geometrical parameters of the aerostatic bearing were optimized to improve its stiffness. Then, the key structural dimension of the aerostatic spindle is optimized in the second-round design to improve the natural frequency of the spindle. Finally, optimal design parameters are acquired and experimentally verified. This research guides the optimal design of aerostatic spindles considering the FSI effect.

Sign in / Sign up

Export Citation Format

Share Document