Design and experimental research of a magnetorheological elastomer isolator working in squeeze/elongation–shear mode

2017 ◽  
Vol 29 (7) ◽  
pp. 1418-1429 ◽  
Author(s):  
Yu Tao ◽  
Xiaoting Rui ◽  
Fufeng Yang ◽  
Gangli Chen ◽  
Leixiang Bian ◽  
...  
Keyword(s):  
Relative Increase ◽  
Shear Mode ◽  
Magnetorheological Elastomer ◽  
Magnetorheological Elastomers ◽  
Vertical Stiffness ◽  
Shear Modes ◽  
Strain Relationship ◽  
Stiffness And Damping Coefficient ◽  
Stiffness And Damping ◽  
Relationship Of

Due to the properties of controllable stiffness and damping, a novel isolator based on magnetorheological elastomers is introduced in this article. According to the experimental results, the initial vertical stiffness and damping coefficient of the magnetorheological elastomer isolator are 1.14 × 106 N/m and 495.8 N s/m, respectively. The relative increase in stiffness and damping is 66.57% and 45.55%, respectively. The isolation transmissibility and root mean square of acceleration response are reduced by 41.2% and 65.3%, respectively. To describe the magnetic-induced stress–strain relationship of the anisotropic magnetorheological elastomers, a theoretical model is presented as magnetorheological elastomers working in squeeze/elongation and shear modes simultaneously. Then, the stiffness formula relating to the magnetic field, strain, and the other demanding parameters is deduced. The analytical results of the stiffness formula are fairly in agreement with the experimental data.

Study on the Mechanical Properties of Magnetorheological Elastomers

2013 ◽  
Vol 774-776 ◽  
pp. 54-57 ◽  
Author(s):  
Yu Fei Wang ◽  
Guo Fei Wang
Keyword(s):  
Mechanical Properties ◽  
Large Deformation ◽  
Shear Mode ◽  
Magnetorheological Elastomer ◽  
Test Set ◽  
Magnetorheological Elastomers ◽  
Magnetorheological Effect ◽  
Magnetic Filed ◽  
Mr Effect

A polyurethane-based magnetorheological elastomer (MR elastomer) was designed, and the magnetorheological effect (MR effect) under shear mode was systematically tested by the designed test set. The results show that the relative MR effect increases with the exterior magnetic filed strength and decreases as the incentive amplitudes increasing. The preload displacement also directly determines the relative MR effect and too large deformation will make the MR effect decreased sharply. But the incentive frequency has no very obviously influence on the relative MR effect.

Wheel–rail dynamic interaction caused by wheel out-of-roundness and its transmission between wheelsets

2021 ◽  
pp. 095440972110165
Author(s):  
Gongquan Tao ◽  
Mengqi Liu ◽  
Qinglin Xie ◽  
Zefeng Wen
Keyword(s):  
Dynamic Interaction ◽  
High Order ◽  
Vibration Measurement ◽  
Bending Vibration ◽  
Vertical Stiffness ◽  
Finite Element Software ◽  
Measurement Results ◽  
Stiffness And Damping Coefficient ◽  
Stiffness And Damping ◽  
Low Order

High-order and low-order wheel out-of-roundness (OOR) often occur on metro train wheels, which can intensify the wheel–rail dynamic interaction. A vehicle–track rigid-flexible coupled dynamics model is built through combining the dynamics software SIMPACK with the finite element software ANSYS, which is validated by field vibration measurement results of vehicle and track. Two adjacent vehicles with two two-axle bogies for each one are considered in the model. The wheel–rail interactions caused by high-order and low-order wheel OOR are investigated. The influence of the wheel–rail interaction caused by wheel OOR on one wheelset on wheel–rail interactions at other 7 wheelsets is explored. The results show that the wheel OOR can excite the first bending vibration of the wheelset and the P2 resonance at a normal operating speed, which can result in a considerable increase of the wheel–rail dynamic interaction and wheelset vibration. The wheel–rail dynamic interaction can be transmitted from the polygonised wheelset to another wheelset of the same bogie through the rail. However, the transmission is negligible from the path of the bogie. The amplitude of wheel OOR has no effect on the transmission ratio of wheel–rail dynamic interaction, but the vertical stiffness and damping coefficient of fasteners greatly influence the transmission. The two wheelsets on the same bogie should be re-profiled simultaneously if the radial run-out for one wheelset exceeds the limit and for the other does not. The effects of vibration transmission between wheelsets and track flexibility need to be taken into account in a model for predicting the development of wheel OOR.

STUDY ON THE VERTICAL STIFFNESS AND DAMPING COEFFICIENT OF TRACTOR TIRE USING SEMI-EMPIRICAL MODEL

2013 ◽  
Vol 83 (5) ◽  
Author(s):  
Đỗ Minh Cường ◽  
Zhu shi Hong ◽  
Đinh Vương Hùng ◽  
Nguyễn Thị Ngọc
Keyword(s):  
Damping Coefficient ◽  
Inflation Pressure ◽  
Vertical Stiffness ◽  
Damping Characteristics ◽  
Increasing Trend ◽  
Tire Stiffness ◽  
Stiffness And Damping Coefficient ◽  
Stiffness And Damping ◽  
Semi Empirical ◽  
Rear Tire

An experiment was conducted to determine the vertical stiffness and damping characteristics of tractor tires for the aim of simulation and design of the tractor suspension system. Three kinds of tractor tires were selected to measure vertical stiffness and damping coefficient by using Free-Vibration Logarithm Decay Method at five levels of tire inflation pressures and two tire loads. The results show that, for all kinds of tire, the stiffness was linearly increased by increasing tire inflation pressure whereas the damping coefficient decreased when tire inflation pressure increased. The stiffness and damping coefficient of tractor tires also depend on the tire size, the structure of tires as front tire or rear tire. Additionally, the damping coefficient shows the increasing trend while the increase in tire stiffness is not clear by increasing tire load. The results also reveal that the appropriate distribution of tire load, tire inflation pressure and tire size can change significantly the tire stiffness and damping coefficient to control tractor vibration. Keywords: Tire stiffness; Damping coefficient; Tractor tire; Tire inflation pressure.

Semi-inverse method for predicting stress–strain relationship from cone indentations

2003 ◽  
Vol 18 (9) ◽  
pp. 2068-2078 ◽  
Author(s):  
A. DiCarlo ◽  
H. T. Y. Yang ◽  
S. Chandrasekar
Keyword(s):  
A Priori ◽  
Model Material ◽  
Material Behavior ◽  
The Finite Element Method ◽  
Stress Strain ◽  
Indentation Tests ◽  
Strain Relationship ◽  
Initial Force ◽  
Relationship Of ◽  
Force Displacement

A method for determining the stress–strain relationship of a material from hardness values H obtained from cone indentation tests with various apical angles is presented. The materials studied were assumed to exhibit power-law hardening. As a result, the properties of importance are the Young's modulus E, yield strength Y, and the work-hardening exponent n. Previous work [W.C. Oliver and G.M. Pharr, J. Mater. Res. 7, 1564 (1992)] showed that E can be determined from initial force–displacement data collected while unloading the indenter from the material. Consequently, the properties that need to be determined are Y and n. Dimensional analysis was used to generalize H/E so that it was a function of Y/E and n [Y-T. Cheng and C-M. Cheng, J. Appl. Phys. 84, 1284 (1999); Philos. Mag. Lett. 77, 39 (1998)]. A parametric study of Y/E and n was conducted using the finite element method to model material behavior. Regression analysis was used to correlate the H/E findings from the simulations to Y/E and n. With the a priori knowledge of E, this correlation was used to estimate Y and n.

Study on Stress-Strain Relationship of Loess

2004 ◽  
Vol 274-276 ◽  
pp. 241-246 ◽  
Author(s):  
Bo Han ◽  
Hong Jian Liao ◽  
Wuchuan Pu ◽  
Zheng Hua Xiao
Keyword(s):  
Stress Strain ◽  
Strain Relationship ◽  
Relationship Of

Nonlinear Oscillations of a Composite Laminated Plate with Parametrically and Externally Excitations

2013 ◽  
Vol 699 ◽  
pp. 641-644
Author(s):  
Xiao Li Bian ◽  
Shuang Bao Li
Keyword(s):  
Thin Plate ◽  
Nonlinear Oscillations ◽  
Plate Theory ◽  
Laminated Plate ◽  
Rectangular Thin Plate ◽  
Third Order ◽  
Composite Laminated Plate ◽  
Strain Relationship ◽  
Relationship Of ◽  
Equations Of Motions

Nonlinear oscillations of a simply-supported symmetric cross-ply composite laminated rectangular thin plate are investigated in this paper. The rectangular thin plate is subjected to the transversal and in-plane excitations. Based on the Reddy’s third-order shear deformation plate theory and the stress-strain relationship of the composite laminated plate, a two-degree-of-freedom non-autonomous nonlinear system governing equations of motions for the composite laminated rectangular thin plate is derived by using the Galerkin’s method. Numerical simulations illustrate that there exist complex nonlinear oscillations for composite laminated rectangular thin plate.

scholarly journals Simulating the Stress-Strain Relationship of Geomaterials by Support Vector Machine

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Hongbo Zhao ◽  
Zenghui Huang ◽  
Zhengsheng Zou
Keyword(s):  
Support Vector Machine ◽  
Constitutive Relationship ◽  
Support Vector ◽  
Nonlinear Relationship ◽  
Ann Model ◽  
Stress Strain ◽  
Svm Model ◽  
Strain Relationship ◽  
Artificial Neural Network Ann ◽  
Relationship Of

Stress-strain relationship of geomaterials is important to numerical analysis in geotechnical engineering. It is difficult to be represented by conventional constitutive model accurately. Artificial neural network (ANN) has been proposed as a more effective approach to represent this complex and nonlinear relationship, but ANN itself still has some limitations that restrict the applicability of the method. In this paper, an alternative method, support vector machine (SVM), is proposed to simulate this type of complex constitutive relationship. The SVM model can overcome the limitations of ANN model while still processing the advantages over the traditional model. The application examples show that it is an effective and accurate modeling approach for stress-strain relationship representation for geomaterials.

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