scholarly journals UNDERSTANDING THE REBOUND SURFACE HARDNESS OF CONCRETE

2015 ◽  
Vol 21 (2) ◽  
pp. 185-192 ◽  
Author(s):  
Katalin Szilágyi ◽  
Adorján Borosnyói ◽  
István Zsigovics
Keyword(s):  
Compressive Strength ◽  
Young’S Modulus ◽  
Material Properties ◽  
Young's Modulus ◽  
Experimental Studies ◽  
Surface Hardness ◽  
High Strength ◽  
Hardness Testing ◽  
Technical Literature ◽  
Two Parameter

Surface hardness testing of materials can be considered as the oldest method to get information about strength related material properties. In recent decades the rebound hammer has been the most popular surface hardness testing device for concrete uniting the advantages of its predecessors. In the technical literature numerous proposals are available for simple, two-parameter regression analyses of rebound surface hardness vs. compressive strength relationship of concrete. The remarkable diversity of the proposed curves implies the need of the more than two-parameter regression techniques to reveal the most pronounced parameters governing hardness behaviour. The objectives of present experimental studies were to carry out dynamic and static hardness tests, Young’s modulus and compressive strength tests on concrete specimens. From the development of the tested properties with time it can be concluded that the rebound hammers provide a hardness value for high strength concretes connected to the Young’s modulus rather than the compressive strength. Present paper includes a parametric simulation and a parameter fitting of the verified phenomenological constitutive model of the authors which recognizes the w/c ratio as the main driver of the interrelated material properties and gives a realistic formulation for the time dependent behaviour of the rebound surface hardness of concrete.

Size- and temperature-dependent Young's modulus and size-dependent thermal expansion coefficient of thin films

2016 ◽  
Vol 18 (31) ◽  
pp. 21508-21517 ◽  
Author(s):  
Xiao-Ye Zhou ◽  
Bao-Ling Huang ◽  
Tong-Yi Zhang
Keyword(s):  
Thin Films ◽  
Thermal Expansion ◽  
Young’S Modulus ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Material Properties ◽  
Essential Role ◽  
Young's Modulus ◽  
Temperature Dependent ◽  
Size Dependent

Surfaces of nanomaterials play an essential role in size-dependent material properties.

Achieving high strength and low Young’s modulus in martensitic Ti-Nb-O alloys

2021 ◽  
pp. 130308
Author(s):  
E.S.N. Lopes ◽  
L.U. dos Santos ◽  
R. Caram ◽  
K.N. Campo
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
High Strength

The Material Properties of Bone-Particle Impregnated PMMA

1986 ◽  
Vol 108 (2) ◽  
pp. 141-148 ◽  
Author(s):  
H. C. Park ◽  
Y. K. Liu ◽  
R. S. Lakes
Keyword(s):  
Shear Modulus ◽  
Young’S Modulus ◽  
Material Properties ◽  
Room Temperature ◽  
Particle Concentration ◽  
Young's Modulus ◽  
Higher Order ◽  
Particle Content ◽  
Bone Particle ◽  
Perfect Bonding

The elastic Young’s modulus and shear modulus of bone-particle impregnated polymethylmethacrylate (PMMA) has been measured experimentally at room temperature as a function of bone particle concentration. It was found that the moduli increased with increasing bone particle content. This increase was less than the stiffness increase predicted by higher-order composite theory [1, 2] under the assumption of perfect bonding between particles and matrix. It was concluded that a bond existed but that it was not a perfect bond.

The Tensile Behavior of High-Strength Carbon Fibers

2016 ◽  
Vol 22 (4) ◽  
pp. 841-844 ◽  
Author(s):  
Tye Langston
Keyword(s):  
Young’S Modulus ◽  
Carbon Fibers ◽  
Young's Modulus ◽  
Weak Link ◽  
Fiber Strength ◽  
Fiber Surface ◽  
High Strength ◽  
Carbon Filament ◽  
Specific Strength ◽  
Macro Scale

AbstractCarbon fibers exhibit exceptional properties such as high stiffness and specific strength, making them excellent reinforcements for composite materials. However, it is difficult to directly measure their tensile properties and estimates are often obtained by tensioning fiber bundles or composites. While these macro scale tests are informative for composite design, their results differ from that of direct testing of individual fibers. Furthermore, carbon filament strength also depends on other variables, including the test length, actual fiber diameter, and material flaw distribution. Single fiber tensile testing was performed on high-strength carbon fibers to determine the load and strain at failure. Scanning electron microscopy was also conducted to evaluate the fiber surface morphology and precisely measure each fiber’s diameter. Fiber strength was found to depend on the test gage length and in an effort to better understand the overall expected performance of these fibers at various lengths, statistical weak link scaling was performed. In addition, the true Young’s modulus was also determined by taking the system compliance into account. It was found that all properties (tensile strength, strain to failure, and Young’s modulus) matched very well with the manufacturers’ reported values at 20 mm gage lengths, but deviated significantly at other lengths.

Calculation of the parameters of mechanical properties of the heart muscle

2020 ◽  
Vol 12 ◽  
pp. 42-52
Author(s):  
S. A. Muslov ◽  
◽  
A. I. Lotkov ◽  
S. D. Arutyunov ◽  
T. M. Albakova ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Elastic Constants ◽  
Heart Muscle ◽  
Human Heart ◽  
Young's Modulus ◽  
Experimental Values ◽  
Two Parameter

A review of studies of the mechanical properties of human and animal heart tissues has been performed. Based on literature data, a form of approximating function is found for the dependence of the Young’s modulus of the ventricles of the human heart on the magnitude of the deformation. The average values of the Young’s modulus and other elastic constants were calculated and compared with the known experimental values. The coefficients C1 and C2 of the two-parameter hyperelastic myocardial Mooney-Rivlin model are calculated.

Simulation of Uniaxial Compression for Flexible Fibers of Wheat Straw Using the Discrete Element Method

2021 ◽  
Vol 64 (6) ◽  
pp. 2025-2034
Author(s):  
Matthew W Schramm ◽  
Mehari Z. Tekeste ◽  
Brian L Steward
Keyword(s):  
Discrete Element Method ◽  
Wheat Straw ◽  
Young’S Modulus ◽  
Uniaxial Compression ◽  
Material Properties ◽  
Young's Modulus ◽  
Discrete Element ◽  
Flexible Fibers ◽  
Dem Model ◽  
Element Method

HighlightsSimulation of uniaxial compression was performed with flexible fibers modeled in DEM.Bond-specific DEM parameters were found to be sensitive in uniaxial compression.A calibration technique that is not plunger-dependent is shown and validated.Abstract. To accurately simulate a discrete element method (DEM) model, the material properties must be calibrated to reproduce bulk material behavior. In this study, a method was developed to calibrate DEM parameters for bulk fibrous materials using uniaxial compression. Wheat straw was cut to 100.2 mm lengths. A 227 mm diameter cylindrical container was loosely filled with the cut straw. The material was pre-compressed to 1 kPa. A plunger (50, 150, or 225 mm diameter) was then lowered onto the compressed straw at a rate of 15 mm s-1. This experimental procedure was simulated using a DEM model for different material properties to generate a simulated design of experiment (DOE). The simulated plunger had a travel rate of 40 mm s-1. The contact Young’s modulus, bond Young’s modulus, and particle-to-particle friction DEM parameters were found to be statistically significant in the prediction of normal forces on the plunger in the uniaxial compression test. The DEM calibration procedure was used to approximate the mean laboratory results of wheat straw compression with root mean square (RMS) percent errors of 3.77%, 3.02%, and 13.90% for the 50, 150, and 225 mm plungers, respectively. Keywords: Calibration, DEM, DOE, Flexible DEM particle, Uniaxial compression, Wheat straw.

High‐entropy eutectic composites with high strength and low Young's modulus

2020 ◽  
Author(s):  
Tapabrata Maity ◽  
Konda Gokuldoss Prashanth ◽  
Özge Balcı ◽  
Grzegorz Cieślak ◽  
Maciej Spychalski ◽  
...  
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
High Strength ◽  
High Entropy
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