scholarly journals Investigation of the frequency properties of a standard linear body

Author(s):  
Vladimir P. Tregubov ◽  
◽  
Nadezhda K. Egorova ◽  

It is known that the Кelvin-Voigt model does not describe stress relaxation, which is observed along with elastic properties in many polymers and biomaterials. In this regard, the standard linear body model is used to describe the properties of these materials. Studies of its properties were mainly limited to the study of its reaction to an instantaneously applied load, as well as to the determination of the time and nature of stress relaxation. Аt the same time, the frequency properties of the standard linear body remained unexplored. In this regard, an analysis of its frequency properties was carried out, which made it possible to study its behavior under vibration exposure. Оn the basis of the equation of motion, the amplitude-frequency response (АFC) was constructed, and its peculiarity was revealed, which consists in the fact that an increase in the damping coefficient leads to a decrease in the maximum value of the АFC only to a certain value greater than one. А further increase in the damping coefficient leads to an increase in the maximum frequency response up to infinity at a frequency that should also be considered resonant. Thus, the frequency response of a standard linear body always has a maximum. The subsequent increase in the damping coefficient leads to the tendency of the maximum frequency response to zero at infinity.

Procedia CIRP ◽  
2021 ◽  
Vol 101 ◽  
pp. 302-305
Author(s):  
Berend Denkena ◽  
Alexander Krödel ◽  
Lars Ellersiek

1982 ◽  
Vol 55 (1) ◽  
pp. 62-65
Author(s):  
W. Batsberg ◽  
O. Kramer

Abstract The experimental result, that the equilibrium force is nearly equal to the pseudoequilibrium force immediately prior to quenching and irradiation, allows the following conclusions: (1) Chain scission during crosslinking is not a serious problem. (2) The network of highly entangled linear chains is effectively at elastic equilibrium immediately prior to crosslinking in the strained state. This would not be the case if the entangled structure remained untrapped. (3) The effect of chain entangling in tightly crosslinked elastomers is large, also at elastic equilibrium. In fact, it is almost quantitatively equal to the pseudo-equilibrium stress relaxation modulus of the uncrosslinked linear polymer. This result is in agreement with the results from the Langley and the two-network methods.


2019 ◽  
Vol 25 ◽  
pp. 20-25
Author(s):  
Dmitry Nasonov ◽  
Mikhail Leontiev ◽  
Vladimir Raevsky ◽  
Anzhelika Volkhonskaya

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2872 ◽  
Author(s):  
Ho-Young Kang ◽  
Chan-Jung Kim ◽  
Jaewoong Lee

Excellent mechanical properties of carbon-fiber-reinforced plastic material (CFRP) demonstrates many possibilities in industries using lightweight materials, but unlike isotropic materials, such as iron, aluminum, and magnesium, they show direction-sensitive properties, which makes it difficult to apply for them. The sensitivity of a modal damping coefficient of a CFRP material over the direction of carbon fiber was examined on spectral input patterns in recent research, but the effect of temperature was not considered up to now. To overcome this, uniaxial vibration tests were conducted using five simple specimens with different direction of carbon fiber in a CFRP specimen, the frequency response functions were experimentally determined and the modal damping coefficients were calculated. It was revealed that the resonance point and the modal damping of the specimen changed according to the change in temperature condition. Based on the experimental results, it was demonstrated that the theoretical frequency response function of the carbon composite material is a function of temperature, and it was confirmed that the nonlinear characteristic of the modal damping was the smallest under the 0 degree of direction of carbon fiber.


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