scholarly journals Experimental Investigation of the Static and Dynamic Compression Characteristics of Limestone Based on Its Initial Damage

2021 ◽  
Vol 11 (16) ◽  
pp. 7643
Author(s):  
Yongqian Wang ◽  
Xuan Wang ◽  
Jiasheng Zhang ◽  
Benshui Yang ◽  
Junhua Chen ◽  
...  
Keyword(s):  
Longitudinal Wave ◽  
Wave Speed ◽  
Dynamic Compression ◽  
Compression Tests ◽  
Longitudinal Wave Velocity ◽  
Static And Dynamic Characteristics ◽  
Damage Degree ◽  
Initial Damage ◽  
Compression Characteristics ◽  
Longitudinal Wave Speed

In the current work a new equation for initial damage assessment of limestone based on plane strain theory is proposed. Detailed investigations of the static and dynamic characteristics of limestone with different initial damage degree, using longitudinal wave speed, and static-dynamic compression tests are performed. This study investigated the static and dynamic characteristics of limestone with different initial damage degree, using longitudinal wave speed, and static-dynamic compression tests. Experimental results show that the degree of initial damage decreases with increasing longitudinal wave speed, which reaches the minimum when the longitudinal wave speed is approximately 6000 m/s, and the smaller the longitudinal wave velocity, the greater the degree of initial damage. The static and dynamic compressive strengths of limestone increase with the longitudinal wave velocity and strain rate, but the elastic modulus and Poisson’s ratio do not change significantly. Finally, based on the experimental results, the definitions of damage threshold value and strain softening are proposed, which further verify the influence of strain rate and initial damage on rock compression characteristics. The present study sheds light on the importance of initial damage for the mechanical state of rock in underground engineering.

Effect of Compressive Stress on Longitudinal Wave Speed in Cementitious Material

2002 ◽  
Author(s):  
Mary L. Hughes ◽  
C. Allen Ross ◽  
Voncile L. Ashley
Keyword(s):  
Constitutive Equation ◽  
Longitudinal Wave ◽  
Uniaxial Compression ◽  
Wave Speed ◽  
Constitutive Relations ◽  
Damage Parameter ◽  
Primary Objective ◽  
Compression Tests ◽  
Depth Of Penetration ◽  
Longitudinal Wave Speed

The Air Force has been interested for some time in the development of computer codes that accurately predict the penetrator trajectory created when munitions are fired into concrete and geomaterial targets, as well as the resulting depth of penetration. Recent work has focused on experimental research performed to determine quasistatic, dynamic, unconfined and confined material properties for development of an elastic/viscoplastic constitutive equation. This constitutive equation has shown some promise in predicting stress and strains but lacks a consistent damage parameter to predict damage or fractures exhibited by the target material during experimental impact tests. Current damage level predictors that employ a scalar damage parameter are not sufficient to predict the directional damage or fracture that occurs in simple uniaxial compression tests of concrete and geomaterials. Tensorial or directional damage parameters coupled with constitutive relations are necessary for better understanding and accurate prediction of damage exhibited when munitions impact concrete and geomaterials. The primary objective of the study described herein was to identify, quantify and characterize damage parameters associated with certain constitutive responses of cementitious and geologic materials. To that end, longitudinal wave speed and biaxial strain data were collected simultaneously on a series of grout cubes as they were being loaded to failure in uniaxial compression. The results of these tests, and a comparison to existing related data [1, 2] are presented.

scholarly journals An Experimental Study on Mechanical Properties for the Static and Dynamic Compression of Concrete Eroded by Sulfate Solution

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5387
Author(s):  
Ao Yao ◽  
Jinyu Xu ◽  
Wei Xia
Keyword(s):  
Mechanical Properties ◽  
Longitudinal Wave ◽  
Energy Absorption ◽  
Wave Velocity ◽  
Concrete Structure ◽  
Mechanical Performance ◽  
Dynamic Compression ◽  
Sulfate Solution ◽  
Static Strength ◽  
Longitudinal Wave Velocity

The mechanical properties of the static and dynamic compression of concrete eroded by a 15% sodium sulfate solution were explored with a 70-mm-diameter true triaxial static-dynamic comprehensive loading test system, and an analysis of the weakening mechanisms for the degree of macroscopic damage and microscopic surface changes of eroded concrete were conducted in combination with damage testing based on relevant acoustic characteristics and SEM scanning. The experience obtained in this paper is used to analyze and solve the problem that the bearing capacity of concrete buildings is weakened due to the decrease in durability under the special conditions of sulfate erosion. The results showed that, in a short time, the properties of concrete corroded by sulfate solution were improved to a certain extent due to continuous hydration. When the corrosion time was prolonged, the internal concrete structure was destroyed after it was eroded by sulfate, and its dynamic and static strength, deformability, and energy absorption were reduced to differing degrees, thus greatly inhibiting the overall mechanical performance of concrete; the dynamic compressive strength changed with strain that exhibited a significant strain rate effect; and, under the influence of sulfate erosion and hydration, the longitudinal wave velocity increased first and then decreased. The longitudinal wave velocity was slower than that of concrete under normal environment and distilled water immersion condition. SEM and acoustic wave analysis indicated that the internal concrete structure was destroyed after it was eroded by sulfate, and its dynamic and static strength, deformability, and energy absorption were reduced to differing degrees, thus greatly inhibiting the overall mechanical performance of concrete.

Measurements of the longitudinal wave speed in thin materials using a wideband PVDF transducer

2003 ◽  
Vol 114 (3) ◽  
pp. 1450-1453 ◽  
Author(s):  
Kwang Yul Kim ◽  
Wei Zou ◽  
Steve Holland ◽  
Wolfgang Sachse
Keyword(s):  
Longitudinal Wave ◽  
Wave Speed ◽  
Longitudinal Wave Speed

Reply to comment on ‘Measuring longitudinal wave speed in solids: two methods and a half’

2006 ◽  
Vol 28 (1) ◽  
pp. L3-L5
Author(s):  
C Fazio ◽  
I Guastella ◽  
R M Sperandeo-Mineo ◽  
G Tarantino
Keyword(s):  
Longitudinal Wave ◽  
Wave Speed ◽  
Longitudinal Wave Speed

Transverse Impact Response of a Linear Elastic Ballistic Fiber Yarn

2011 ◽  
Vol 78 (5) ◽  
Author(s):  
Bo Song ◽  
Hwun Park ◽  
Wei-Yang Lu ◽  
Weinong Chen
Keyword(s):  
Longitudinal Wave ◽  
Transverse Wave ◽  
Wave Speed ◽  
Impact Response ◽  
High Speed Photography ◽  
Transverse Impact ◽  
Ballistic Performance ◽  
Linear Elastic ◽  
The Impact ◽  
Longitudinal Wave Speed

Transverse impact response of a linear elastic Kevlar® KM2 fiber yarn was determined at various striking speeds from Hopkinson bar and gas gun experiments incorporated with high-speed photography techniques. Upon transverse impact, a triangle shape was formed in the fiber yarn. Both longitudinal and transverse waves were produced and propagated outwards the fiber yarn. Both the angle of the triangle and Euler transverse wave speed vary with striking speeds. The relationship between the Euler transverse wave speed and the striking speed was determined. The transverse impact response of the fiber yarn was also analyzed with a model, which agrees well with the experimental results. The model shows that the longitudinal wave speed is critical in the ballistic performance of the fiber yarn. At a certain striking speed, a higher longitudinal wave speed produces a higher Euler transverse wave speed, enabling us to spread the load and dissipate the impact energy faster, such that the ballistic performance of the fiber yarn is improved.

scholarly journals Measuring longitudinal wave speed in solids: two methods and a half

2006 ◽  
Vol 27 (4) ◽  
pp. 687-701 ◽  
Author(s):  
C Fazio ◽  
I Guastella ◽  
R M Sperandeo-Mineo ◽  
G Tarantino
Keyword(s):  
Longitudinal Wave ◽  
Wave Speed ◽  
Longitudinal Wave Speed

Self-Sustained Fracture Waves in Soda-Lime Glass

2010 ◽  
Vol 662 ◽  
pp. 95-104 ◽  
Author(s):  
M. Munawar Chaudhri
Keyword(s):  
Residual Stress ◽  
Longitudinal Wave ◽  
Lead Oxide ◽  
Wave Speed ◽  
Soda Lime ◽  
Oxide Glass ◽  
Soda Lime Glass ◽  
Lead Glass ◽  
Fracture Wave ◽  
Longitudinal Wave Speed

High-speed framing photography in conjunction with circularly polarised light has been employed to monitor qualitatively the state of residual stress in Prince Rupert’s drops of soda-lime glass undergoing disintegration by a self-sustained fracture wave in the glass drops. It is revealed that the fracture wave through a Prince Rupert’s drop is driven by the residual stress in the drop, with the propagation speed of the fracture wave being (1700 ± 100) ms-1, which is close to the terminal speed of individual cracks in the soda-lime glass, but is much smaller than the longitudinal wave speed of 5300 ms-1 in the glass. These observations support our recently reported observations and also give support to our conclusions that the fracture wave speed of a self-sustained fracture wave is equal to the terminal speed of individual cracks in the glass. Some preliminary observations from fracture waves in Prince Rupert’s drops of a lead oxide glass are also described, which show that in Prince Rupert’s drops of the lead oxide glass the fracture wave is also self-sustained and it travels through the drop at a steady and stable speed of (1300 ± 100) ms-1, which is also considerably smaller than the longitudinal wave speed of 4800 ms-1 in the lead glass. A brief comment is also made on the fracture waves observed by other workers in brittle oxide glasses and solids generated by plate impacts and shock waves.

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