Dynamic properties and microstructural response to shock loading of Armco iron at different temperatures

1996 ◽  
Author(s):  
H. Nahme ◽  
M. Hiltl ◽  
W. Arnold
Keyword(s):  
Shock Loading ◽  
Armco Iron ◽  
Dynamic Properties ◽  
Different Temperatures

FEM Analysis of Cylindrical Structural Elements under Local Shock Loading

2014 ◽  
Vol 566 ◽  
pp. 499-504 ◽  
Author(s):  
Leopold Kruszka ◽  
Yu.S. Vorobiov ◽  
N.Yu. Ovcharova
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Strain State ◽  
Shock Loading ◽  
Dynamic Properties ◽  
Fem Analysis ◽  
Finite Deformations ◽  
High Rate ◽  
Structural Elements ◽  
Stress Strain

High rate deformations of structures cylindrical elements are considered 3D formulation. Elastic-plastic finite deformations and dynamic properties of material take into account. The problem become geometrically and physically nonlinear and finite element method is used. The numerical analyses of dynamics stress-strain state of real structures elements is executed.

Experimental and Numerical Study on Dynamic Properties of Viscoelastic Microvibration Damper Considering Temperature and Frequency Effects

2016 ◽  
Vol 11 (6) ◽  
Author(s):  
Chao Xu ◽  
Zhao-Dong Xu ◽  
Teng Ge ◽  
Ya-Xin Liao
Keyword(s):  
Loss Factor ◽  
Numerical Study ◽  
Dynamic Properties ◽  
Frequency Effect ◽  
Solid Model ◽  
Temperature Dependent ◽  
Frequency Effects ◽  
Proposed Model ◽  
Different Temperatures ◽  
Increasing Temperature

This work presents an experimental and numerical study on the dynamic properties of viscoelastic (VE) microvibration damper under microvibration conditions at different frequencies and temperatures. The experimental results show that the storage modulus and the loss factor of VE microvibration damper both increase with increasing frequency but decrease with increasing temperature. To explicitly and accurately represent the temperature and frequency effects on the dynamic properties of VE microvibration damper, a modified standard solid model based on a phenomenological model and chain network model is proposed. A Gaussian chain spring and a temperature-dependent dashpot are employed to reflect the temperature effect in the model, and the frequency effect is considered with the nature of the standard solid model. Then, the proposed model is verified by comparing the numerical results with the experimental data. The results show that the proposed model can accurately describe the dynamic properties of VE microvibration damper at different temperatures and frequencies.

Dynamic Mechanical Properties of Steel Fiber-Reinforced Concrete Subjected to Shock Loading

2011 ◽  
Vol 52-54 ◽  
pp. 703-708
Author(s):  
Fang Jiang ◽  
Yue Sheng Tan ◽  
Dong Zhao
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Shock Loading ◽  
Dynamic Properties ◽  
Constitutive Relations ◽  
Dynamic Mechanical Properties ◽  
Fiber Reinforced Concrete ◽  
Steel Fiber Reinforced Concrete ◽  
Specific Internal Energy ◽  
Dynamic Mechanical

One-stage light gas gun is used to study the dynamic mechanical properties of reinforced concrete (SFRC) subjected to shock loading. The material of projectile is the same as of the target. The stress-time curves are recorded by three manganin pressure transducers embedded in the targets beforehand. The data of experiment are analyzed by self-designed program using the path line principle of Lagrangian analysis method. With the stress records, complete histories of particle velocity, density (and thus strain) and specific internal energy can be obtained at any point within the gaged region of the material. Moreover, the numerical constitutive relations of RC are obtained and the strain rate ranges from 104 to 105 per second. The result of experiment indicates that the stress-strain curves of SFRC present stagnant-return properties. And some other dynamic properties can be gained, such as rate dependent, waveform dissipation etc.

Dynamic Constitutive Relation of EMC

2010 ◽  
Vol 129-131 ◽  
pp. 988-992
Author(s):  
Bo Wang ◽  
Tong Chen ◽  
Xue Feng Shu
Keyword(s):  
Yield Strength ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Properties ◽  
Strain Rates ◽  
Hopkinson Pressure Bar ◽  
Static Tests ◽  
Good Accordance ◽  
Different Temperatures ◽  
Split Hopkinson ◽  
Pressure Bar

In this paper, dynamic properties of EMC were studied at different temperatures and different strain rates. Firstly EMC was investigated by quasi-static tests. Secondly a series of dynamic compressive experiments of EMC were conducted using the Split Hopkinson Pressure Bar (SHPB) at sectional height of strain rates. Thirdly EMC constants in ZWT model were determined from experiments. Corresponding measurements were conducted at temperatures ranging from 20°C to 160°C. The results indicate that the yield strength and flow stress of EMC increase remarkably with the increase of strain rate and it is shows that the assembled curve is fit good accordance with actual the experimental curve. However, the yield strength of EMC is a little change with the increase of temperature which is ranging from 20°C to 160°C.

On the Formation of Shock-Twins in Prestrained Armco Iron

1967 ◽  
Vol 25 ◽  
pp. 320-321
Author(s):  
S. Mahajan
Keyword(s):  
Shock Loading ◽  
Armco Iron ◽  
Deformation Twin ◽  
Longitudinal Direction ◽  
Twin Lamella ◽  
Second Stage ◽  
Thin Foils ◽  
Analysis Of Results ◽  
Mechanical Twins ◽  
Two Stages

The formation of a deformation twin can he divided into two stages: nucleation of a twin lamella, and growth of this lamella into an observable twin. However, the second stage can be further subdivided into three sub-headings: (i) propagation of the lamella parallel to its long dimension, i.e., the longitudinal direction, (ii) thickening parallel to its short dimension, and (iii) growth of this nucleus in a direction perpendicular to the plane containing the long and the short dimensions.The purpose of the present investigation was to study the effect of existing substructure on the formation of mechanical twins in Armco iron. These twins were produced by shock-loading the annealed and prestrained samples to 50 and 100 Kbars, using a plane-wave generator. It should be emphasized that the desired objective can be achieved without resorting to shockloading, but thin foils from an impulsively loaded sample possess the advantage of containing many more twins and twin nuclei than foils from more conventionally stressed material, thus facilitating the analysis of results.

scholarly journals Resonant Column Test on the Frozen Silt Soil Modulus and Damping at Different Temperatures

2017 ◽  
Author(s):  
Xiaobo Yu ◽  
Rui Sun ◽  
Xiaoming Yuan ◽  
Zhuoshi Chen ◽  
Jiuqi Zhang
Keyword(s):  
Shear Modulus ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Negative Temperature ◽  
Frozen Soil ◽  
Resonant Column ◽  
Engineering Construction ◽  
Resonant Column Test ◽  
Triaxial Apparatus ◽  
Different Temperatures

The shear modulus and damping ratio of frozen soil are thebasic parameters of its dynamic properties and are often testedwith the dynamic triaxial apparatus. However, the resonantcolumn apparatus is more suitable for the testing at the microstrainlevel. A resonant column apparatus was here used toidentify the varying modes with negative temperature of theinitial shear modulus, modulus ratio, and damping ratio of frozensilt. Correction factor curves indicate that the temperaturehas a great effect on the shear modulus and damping ratio offrozen silt. The curves also show that, within the sensitive stage,the temperature significantly affects the modulus and damping.Within the insensitive stage, the modulus and dampingwere insensitive to the temperature. The experimental resultsand analysis given here provide support for improving seismicdesign codes and offer reasonable parameters for seismicresponse analysis in engineering construction in cold regions.

scholarly journals II. On some thermo-dynamic properties of solids

1859 ◽  
Vol 9 ◽  
pp. 254-254 ◽  
Keyword(s):  
Dynamic Properties ◽  
Elastic Force ◽  
Minute Quantity ◽  
Different Temperatures ◽  
Capillary Attraction ◽  
Quantity Of Heat ◽  
Elastic Spring

A résumé of the greater part of this paper has already appeared in the ‘Proceedings’ for January 29, June 18, and November 26, 1857. The author has since examined the expansion by heat of wood cut across the grain, which, as well as that cut in the direction of the fibre, he finds to be increased by tension and decreased by moisture. When a sufficient quantity of water has been absorbed the expansibility by heat ceases, and wood is contracted in each di­rection by rise of temperature. Nevertheless, when wood, saturated with water, is weighed in water of different temperatures, the result shows cubical expansion of the substance of the wood by heat. The inference drawn by the author from these facts is, that the contraction of the dimensions of wet wood is owing to the action of heat in di­minishing the force of capillary attraction, and that thus the walls of the minute cells and tubes of the woody structure are partially re­lieved from a force which thrusts them asunder, a small quantity of water exuding at the same time. In the case of wet wood which contracts by heat, he finds, in accordance with Professor Thomson’s formula, that a rise of temperature is produced by the application of tension. In conformity with the deductions of the same philosopher, the author has also been able to detect experimentally the minute quantity of heat absorbed, in bending or twisting an elastic spring, arising from the diminution of the elastic force of metals with a rise of temperature.

Study on experiment and modeling of viscoelastic damper considering interfacial effect of matrix rubber/carbon black

2021 ◽  
pp. 1-28
Author(s):  
Teng Ge ◽  
Zhao-Dong Xu ◽  
Fuh-Gwo Yuan
Keyword(s):  
Experimental Study ◽  
Dynamic Properties ◽  
Excitation Frequency ◽  
Control Device ◽  
Structural Vibration ◽  
Modeling Analysis ◽  
Proposed Model ◽  
Excited Vibration ◽  
Different Temperatures ◽  
Good Energy

Abstract Viscoelastic (VE) dampers are a kind of effective passive vibration control device and widely used to attenuate structural vibration. In this paper, experimental study and multi-scale modeling analysis on the VE damper for reducing wind-excited vibration are carried out. First, an experimental study on VE damper is conducted to reveal the dynamic properties of VE damper. The experimental results show that the dynamic properties of VE material are influenced by excitation frequency and insignificantly affected by displacement amplitude, and the VE material has good energy dissipation capacity. Second, the damping mechanism of VE damper is analyzed from micro-perspectives by considering the influence of cross-linked and free molecular chain networks. Then a novel type spherical chain network model based on the chain network microstructure is proposed. The proposed model is verified by comparing the experimental data and the mathematical results, which indicates that the proposed model can accurately describe the dynamic properties of VE damper affected by different temperatures, frequencies and displacements.

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