scholarly journals A constitutive model of the dynamic shear modulus dependence on temperature, prestrain, dynamic strain amplitude and magnetic field for magneto-sensitive elastomer

2021 ◽  
Author(s):  
Jonas Lejon ◽  
Bochao Wang ◽  
Leif Kari
Keyword(s):  
Magnetic Field ◽  
Shear Modulus ◽  
Constitutive Model ◽  
Strain Amplitude ◽  
Dynamic Strain ◽  
Dynamic Shear Modulus ◽  
Dynamic Shear

Measurements on the Temperature, Dynamic Strain Amplitude and Magnetic Field Strength Dependence of the Dynamic Shear Modulus of Magnetosensitive Elastomers in a Wide Frequency Range

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Jonas Lejon ◽  
Leif Kari
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Shear Modulus ◽  
Magnetic Field Strength ◽  
Strain Amplitude ◽  
Wide Frequency Range ◽  
Dynamic Strain ◽  
Dynamic Shear Modulus ◽  
Frequency Range ◽  
Temperature Dynamic

A measurement study is conducted to investigate how changes in temperature, dynamic strain amplitude, and magnetic field strength influence the behavior of a magnetosensitive material. During the measurements seven temperatures, four magnetic fields, and three dynamic strain amplitudes are used over a 200 to 800 Hz frequency range. The results indicate a decrease in shear modulus magnitude as the dynamic strain amplitude is increased. As the frequency and magnetic field strength increases the magnitude increases. However, the measurements indicate that the temperature is the most influential of the parameters as the material stiffens significantly when the temperature reaches the transition phase. Understanding the temperature dependence increases the knowledge of magnetosensitive materials.

Shear Modulus and Damping Ratio of Gravel Material

2011 ◽  
Vol 105-107 ◽  
pp. 1426-1432 ◽  
Author(s):  
De Gao Zou ◽  
Tao Gong ◽  
Jing Mao Liu ◽  
Xian Jing Kong
Keyword(s):  
Shear Modulus ◽  
Shear Strain ◽  
Strain Amplitude ◽  
Damping Ratio ◽  
Confining Pressure ◽  
Dynamic Shear Modulus ◽  
Test Results ◽  
Dynamic Shear ◽  
Data Points ◽  
Shear Strain Amplitude

Two of the most important parameters in dynamic analysis involving soils are the dynamic shear modulus and the damping ratio. In this study, a series of tests were performed on gravels. For comparison, some other tests carried out by other researchers were also collected. The test results show that normalized shear modulus and damping ratio vary with the shear strain amplitude, (1) normalized shear modulus decreases with the increase of dynamic shear strain amplitude, and as the confining pressure increases, the test data points move from the low end toward the high end; (2) damping ratio increases with the increase of shear strain amplitude, damping ratio is dependent on confining pressure where an increase in confining pressure decreased damping ratio. According to the test results, a reference formula is proposed to evaluate the maximum dynamic shear modulus, the best-fit curve and standard deviation bounds for the range of data points are also proposed.

scholarly journals Study on Dynamic Characteristics of Rubber-Red Clay Mixtures

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Kaisheng Chen ◽  
Qinqin Wang ◽  
Dipu Luo ◽  
Bo Zhou ◽  
Kun Zhang
Keyword(s):  
Particle Size ◽  
Shear Modulus ◽  
Vibration Frequency ◽  
Damping Ratio ◽  
Rubber Particle ◽  
Confining Pressure ◽  
Dynamic Strain ◽  
Dynamic Shear Modulus ◽  
Dynamic Shear ◽  
Red Clay

Rubber powder formed from discarded tire rubber is mixed with red clay to form a rubber-red clay mixture. The dynamic triaxial test was carried out on the mixtures under different conditions. The effects of rubber content, rubber particle size, moisture content of mixed soil, compactness, confining pressure, and vibration frequency on shear strain relation, dynamic shear modulus, and damping ratio of the mixture were investigated. The results show that under the same dynamic strain, the dynamic shear stress-strain curve of rubber mixed soil decreases with the increase in rubber particle content and moisture content and decrease in rubber particle size. On the other hand, it increases with the increase in compactness, confining pressure, and vibration frequency, and as the dynamic strain increases, the τd-γd curve becomes more nonlinear. In addition, with the increase in the rubber particle content, the dynamic shear modulus decreased while the damping ratio increased. When the content was 2%, the change was fastest. After continued addition, it gradually became stable, and when the decrease in rubber particle size also shows the same pattern, 2.00 mm rubber-red clay mixture shows better structure. The water content has great influence on dynamic shear modulus and damping ratio of rubber-red clay mixtures. With the increase in compactness, confining pressure, and vibration frequency, the interaction between mixed soil particles was enhanced, the dynamic shear modulus increased, and the damping ratio decreased.

Dynamic Shear Modulus and Damping Ratio for Threshold Strain in Cohesionless Soils

2011 ◽  
Vol 105-107 ◽  
pp. 1603-1606 ◽  
Author(s):  
Xiao Xia Guo
Keyword(s):  
Shear Modulus ◽  
Damping Ratio ◽  
Dissipation Function ◽  
Dynamic Strain ◽  
Dynamic Shear Modulus ◽  
Dynamic Shear ◽  
Soil Behavior ◽  
Cohesionless Soils ◽  
Skeleton Curve ◽  
Threshold Strain

Based on modern ideas of thermomechanics, small strain dynamic dissipation function of Hardin-Drnevich model for soils is formulated using the assumptions of the beeline and the skeleton curve shift laws. Fundamentally, for cohesionless soils, two types of cyclic strain thresholds are identified: first threshold strain and second threshold strain represent boundaries between fundamentally different dynamic characteristics of cyclic soil behavior. Comparison between the two threshold shear strain values and dynamic degradation curves obtained on exactly the same soils, the results showed that the ratio of secant modulus and maximum dynamic shear modulus for the first threshold strain are almost 1.0, and the damping ratio is almost constant. When dynamic strain level exceeds the second threshold strain, the soil behavior is considerably at nonlinear, and the primary deformation mechanism is related to fabric changes during cyclic loading. The first and the second threshold strains are therefore essential for the understanding and solving soil dynamic problems.

scholarly journals The effect of fluid saturation on the dynamic shear modulus of tight sandstones

2017 ◽  
Vol 14 (5) ◽  
pp. 1072-1086 ◽  
Author(s):  
Dongqing Li ◽  
Jianxin Wei ◽  
Bangrang Di ◽  
Pinbo Ding ◽  
Da Shuai
Keyword(s):  
Shear Modulus ◽  
Dynamic Shear Modulus ◽  
Dynamic Shear ◽  
Fluid Saturation

Experimental Study on Dynamic Characteristics of Ionic Soil Stabilizer Reinforcing Red Clay

2011 ◽  
Vol 374-377 ◽  
pp. 1391-1395
Author(s):  
Xue Song Lu ◽  
Wei Xiang
Keyword(s):  
Shear Modulus ◽  
Shear Strain ◽  
Dynamic Condition ◽  
Damping Ratio ◽  
Confining Pressure ◽  
Natural Soil ◽  
Dynamic Shear Modulus ◽  
Dynamic Shear ◽  
Red Clay ◽  
Soil Stabilizer

Based on the red clay of Wuhan reinforced by Ionic Soil Stabilizer, the red clay soil is treated by different matches of ISS at first, then is tested in the Atterberg limits test and dynamic triaxia test. The results show that the plastic index decreases, and the red clay were greatly improved under the dynamic condition, the maximum dynamic shear modulus ratio acquired an incensement of 27.72% on average after mixing the ISS into the red clay. In addition, It was concluded that the confining pressure influenced the dynamic shear modulus and damping ratio to a certain extent. Given the same strain conditions, with the incensement of confining pressure increases, the dynamic shear modulus increased and the damping ratio decreased. Moreover, when plotting the dynamic shear modulus versus the dynamic shear strain, the similar curve can be formed for both the natural soil and the modified one, the dynamic shear modulus monotonously decreased with the incensement of the dynamic shear strain. However, the value of dynamic shear modulus differed in the same shear strain between the natural soil and the soil modified by ISS.

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