The Study on Dynamic Mechanical Response under Staged Loading

2014 ◽  
Vol 501-504 ◽  
pp. 115-119
Author(s):  
Fei Luo ◽  
Zhan Yuan Zhu ◽  
Lin Zhi Cui ◽  
Gao Min Li ◽  
Yi Ting He
Keyword(s):  
Energy Dissipation ◽  
Residual Strain ◽  
Dynamic Stress ◽  
Mechanical Response ◽  
Stress Amplitude ◽  
Testing Machine ◽  
Morphological Characteristics ◽  
Confining Pressure ◽  
Dynamic Mechanical ◽  
Microscopic Damage

Based on MTS-810 type vibration testing machine, morphological characteristics of hysteretic curves of frozen clay are quantitatively studied, and dynamic mechanical response are analyzed consisting of stiffness, viscosity, degree of microscopic damage, residual strain and energy dissipation. The studies have shown that the higher vibration frequencies are, the greater the stiffness is, while the smaller viscosity, the degree of microscopic damage, residual strain and energy dissipation are. Stiffness, viscosity, degree of microscopic damage, residual strain and energy dissipation are less affected by confining pressure. With increasing dynamic stress amplitude, stiffness decreases gradually, while viscosity, degree of microscopic damage, residual strain and energy dissipation increase gradually.

The Research on the Hysteresis Curve Shape Characteristics of Frozen Soil

2014 ◽  
Vol 670-671 ◽  
pp. 382-386
Author(s):  
Ling Zhi Cui ◽  
Gao Min Li ◽  
Li Dong Qiu ◽  
Yi Ting He ◽  
Lei Mao ◽  
...  
Keyword(s):  
Dynamic Stress ◽  
Stress Amplitude ◽  
Morphological Characteristics ◽  
Confining Pressure ◽  
Frozen Soil ◽  
Hysteresis Curve ◽  
Short Axis ◽  
Curve Shape ◽  
Hysteretic Characteristics ◽  
Shape Characteristics

Under the effect of periodic cycle load, the frozen soil exists hysteretic characteristics. According to the research, the five parameters which are the residual strain , the numerical of short axis to long axis of the hysteretic curve , the slope of the hysteretic curve long axis k, the distance of adjacent hysteretic curve center point d and the area surrounded by hysteretic curve S are used to quantitatively represent the morphological characteristics of the hysteretic curve. The hysteretic curve of frozen soil is not a standard ellipse. Its morphological characteristics relate to the initial loading position. The morphological characteristics of the hysteretic curve of different soil affected by frequency, confining pressure and dynamic stress amplitude are different.

Study on Static and Dynamic Mechanical Property of Sandwich Plate with Aluminum Foam Core under Confining Pressure

2011 ◽  
Vol 488-489 ◽  
pp. 690-693
Author(s):  
Guang Ping Zou ◽  
Zhong Liang Chang ◽  
Rui Rui Wang
Keyword(s):  
Mechanical Property ◽  
Sandwich Structure ◽  
Aluminum Foam ◽  
Fiber Composite ◽  
Testing Machine ◽  
Basalt Fiber ◽  
Confining Pressure ◽  
Dynamic Mechanical Property ◽  
Foam Core ◽  
Dynamic Mechanical

In this paper, the sandwich structure which is consist by the aluminum foam core and CBF(continuous basalt fiber) composite plate is tested by the static and dynamic mechanical property under confining pressure, and the confining pressure experiment is done through add cylindrical tube to the sandwich structure circular specimens. The static mechanical property is tested by WDW3100 electronic universal testing machine, and its dynamic mechanical property is tested by the SHPB(Spilt Hopkinson Press Bar) device, Besides, the strain rate effect of this sandwich structure under confining pressure is tested too, From the experiment results we can see the static and dynamic mechanical properties of confining and no confining results is very different, and this study will provide references for further numerical simulation and damage studying of this kind of sandwich structure.

scholarly journals Undrained Dynamic Behavior of Reinforced Subgrade under Long-Term Cyclic Loading

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Min Geng ◽  
Debin Wang ◽  
Peiyong Li
Keyword(s):  
Elastic Modulus ◽  
Cyclic Loading ◽  
Dynamic Behavior ◽  
Vibration Frequency ◽  
Dynamic Stress ◽  
Stress Amplitude ◽  
Confining Pressure ◽  
Reinforced Soil ◽  
Dynamic Elastic Modulus

To study the dynamic behavior of reinforced subgrade, a series of undrained cyclic triaxial tests of reinforced soil (the specimen a height of 50 cm and a diameter of 20 cm) were performed in this paper. The specimens were tested by varying confining pressure, vibration frequency, dynamic stress amplitudes, and reinforced layers. Orthogonal experiment is a better way to optimize the process of experiment. Impact on dynamic behavior of the reinforced soil specimens is discussed through orthogonal design of experiments in four factors and three levels. This study has demonstrated that the order of dynamic elastic modulus of reinforced soil is influenced by dynamic stress amplitude, frequency, reinforced layer, and confining pressure within changing in factor level. The dynamic stress amplitude has great influence on the dynamic elastic modulus of reinforced soil. The bearing capacity and dynamic elastic modulus of reinforced subgrade decrease slightly with the increase of dynamic strain. Frequency has an influence on the dynamic elastic modulus. It is shown that the cumulative strain of reinforced soil is related to the vibration frequency. The test results also exemplify the reinforced subgrade restrict lateral displacement of subgrade and reduce settlement of subgrade under long-term cyclic loading.

scholarly journals Experiments on Mechanical Response and Energy Dissipation Behavior of Rockburst-Prone Coal Samples Under Impact Loading

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Jinbao Tang ◽  
Sheng Li ◽  
Guangsheng Qin ◽  
Wanjie Lu ◽  
Zhijie Zhu ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Energy Dissipation ◽  
Strain Rate ◽  
Impact Loading ◽  
Mechanical Response ◽  
Peak Stress ◽  
Dynamic Elastic Modulus ◽  
Dissipated Energy ◽  
Peak Strain ◽  
Dynamic Mechanical

To reveal the dynamic mechanical response and energy dissipation behavior of rockburst-prone coal samples under impact loading, the compressive experiments on Xinzhouyao coals (prone) and Machang coals (nonprone) under different impact loadings were carried out using the Split Hopkinson Pressure Bar (SHPB). The dynamic mechanical properties were studied, including dynamic elastic modulus, strain rate, peak stress, peak strain, dynamic increment factor, and energy dissipation. The results show that the dynamic elastic modulus, peak stress, and peak strain of both prone and nonprone coals perform an obvious correlation with the increase of strain rate. The strain rate strengthening effect on the dynamic elastic modulus and compressive strength of rockburst-prone coal samples are more significant, reflected by the greater increment with the increase of strain rate, while the dynamic increment factors of both prone and nonprone coals show apparent strain rate strengthening. The incident, reflected, and transmitted energy of both two coals linearly increases with the impact velocity, although the increased rate may be different. The dissipated energy of rockburst-prone coal samples increases faster, while the rate of the increase of the dissipated energy is more stable with strain rate. The results may provide an important reference for revealing the failure law of engineering-scaled coal mass suffered by rockburst.

scholarly journals Experimental study on permanent deformation characteristics of coarse-grained soil under repeated dynamic loading

2021 ◽  
Author(s):  
Huihao Mei ◽  
Sajjad Satvati ◽  
Wuming Leng
Keyword(s):  
Stress State ◽  
Strain Rate ◽  
Dynamic Stress ◽  
Stress Amplitude ◽  
Permanent Deformation ◽  
Confining Pressure ◽  
Coarse Grained ◽  
Deformation Characteristics ◽  
Permanent Strain ◽  
Coarse Grained Soil

AbstractPractical assessment of subgrade settlement induced by train operation requires developing suitable models capable of describing permanent deformation characteristics of subgrade filling under repeated dynamic loading. In this paper, repeated load triaxial tests were performed on coarse-grained soil (CGS), and the axial permanent strain of CGS under different confining pressures and dynamic stress amplitudes was analysed. Permanent deformation behaviors of CGS were categorized based on the variation trend of permanent strain rate with accumulated permanent strain and the shakedown theory. A prediction model of permanent deformation considering stress state and number of load cycles was established, and the ranges of parameters for different types of dynamic behaviors were also divided. The results indicated that the variational trend of permanent strain rate with accumulated permanent strain can be used as a basis for classifying dynamic behaviors of CGS. The stress state (confining pressure and dynamic stress amplitude) has significant effects on the permanent strain rate. The accumulative characteristics of permanent deformation of CGS with the number of load cycles can be described by a power function, and the model parameters can reflect the influence of confining pressure and dynamic stress amplitude. The study’s results could help deepen understanding of the permanent deformation characteristics of CGS.

scholarly journals Tuning of Static and Dynamic Mechanical Response of LPBFed AlSi10Mg Lattice Structures through heat Treatments

2021 ◽  
Author(s):  
Jacopo Fiocchi ◽  
Chiara Bregoli ◽  
Giulio Gerosa ◽  
Ausonio Tuissi ◽  
Carlo Alberto Biffi
Keyword(s):  
Mechanical Response ◽  
Heat Treatments ◽  
Lattice Structures ◽  
Dynamic Mechanical

An investigation of the dynamic mechanical response of healing cortical bone

1994 ◽  
Vol 27 (6) ◽  
pp. 826
Author(s):  
C.A. Brown ◽  
H.C. Ward ◽  
C.F. Abrams ◽  
S.C. Roe ◽  
D.J. Deyoung ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Mechanical Response ◽  
Dynamic Mechanical

Cure and Dynamic-Mechanical Behaviors of Vinyl Ester Resinfilled with Multi-Walled Carbon Nanotubes

2010 ◽  
Vol 150-151 ◽  
pp. 1413-1416 ◽  
Author(s):  
Hong Yan Chen ◽  
Zhen Xing Kong ◽  
Ji Hui Wang
Keyword(s):  
Carbon Nanotubes ◽  
Vinyl Ester ◽  
Mechanical Response ◽  
Cure Kinetics ◽  
Crosslinking Density ◽  
Vinyl Ester Resin ◽  
Scanning Calorimetry ◽  
Dynamic Mechanical ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

The cure kinetics of Derakane 411-350, a kind of vinyl ester resin, and its suspensions containing multi-walled carbon nanotubes( MWCNTs) were investigated via non-isothermal dynamic scanning calorimetry (DSC) measurements. The results showed that incorporation of MWCNTs into vinyl ester resin excessively reduces polymerization degree and crosslinking density of vinyl ester resin. For suppressing the negative effect caused by nanotubes, the higher temperature initiator combined with the initiator MEKP was used. Dynamic-mechanical Behavior testing was then carried out on the cured sample in order to relate the curing behavior of MWCNTs modified resin suspensions to mechanical response of their resulting nanocomposites. It was revealed that nanocomposites containing MWCNTs possessed larger storage modulus values as well as higher glass transition temperatures (Tg) as compared to those without MWCNTs after using mixed intiators system to improve the degree of cure.

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