Structural disorder effects on the tensile strength distribution of heterogeneous brittle materials with emphasis on fiber networks

2004 ◽  
Vol 70 (6) ◽  
Author(s):  
Dionissios T. Hristopulos ◽  
Tetsu Uesaka
Keyword(s):  
Tensile Strength ◽  
Brittle Materials ◽  
Structural Disorder ◽  
Strength Distribution ◽  
Fiber Networks ◽  
Disorder Effects

scholarly journals Determination of uniaxial tensile strength of brittle materials using tubular samples

2021 ◽  
Vol 833 (1) ◽  
pp. 012016
Author(s):  
D J Guerrero-Miguel ◽  
M I Alvarez-Fernández ◽  
M B Prendes-Gero ◽  
C González-Nicieza
Keyword(s):  
Tensile Strength ◽  
Brittle Materials ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Strength

scholarly journals Characterizing Distributions of Tensile Strength and Crack Precursor Size to Evaluate Filler Dispersion Effects and Reliability of Rubber

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 203 ◽  
Author(s):  
Christopher G. Robertson ◽  
Lewis B. Tunnicliffe ◽  
Lawrence Maciag ◽  
Mark A. Bauman ◽  
Kurt Miller ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Average Diameter ◽  
Strength Distribution ◽  
Glass Beads ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Failure Distribution ◽  
Filler Dispersion ◽  
Control Compound ◽  
Styrene Butadiene

Undispersed filler agglomerates or other substantial inclusions/contaminants in rubber can act as large crack precursors that reduce the strength and fatigue lifetime of the material. To demonstrate this, we use tensile strength (stress at break, σb) data from 50 specimens to characterize the failure distribution behavior of carbon black (CB) reinforced styrene-butadiene rubber (SBR) compounds. Poor mixing was simulated by adding a portion of the CB late in the mixing process, and glass beads (microspheres) with 517 μm average diameter were introduced during milling to reproduce the effects of large inclusions. The σb distribution was well described with a simple unimodal Weibull distribution for the control compound, but the tensile strengths of the poor CB dispersion material and the compounds with the glass beads required bimodal Weibull distributions. For the material with the lowest level of glass beads—corresponding to less than one microsphere per test specimen—the bimodal failure distribution spanned a very large range of σb from 13.7 to 22.7 MPa in contrast to the relatively narrow σb distribution for the control from 18.4 to 23.8 MPa. Crack precursor size (c0) distributions were also inferred from the data, and the glass beads introduced c0 values in the 400 μm range compared to about 180 μm for the control. In contrast to σb, critical tearing energy (tear strength) was unaffected by the presence of the CB agglomerates and glass beads, because the strain energy focuses on the pre-cut macroscopic crack in the sample during tear testing rather than on the microscopic crack precursors within the rubber. The glass beads were not detected by conventional filler dispersion measurements using interferometric microscopy, indicating that tensile strength distribution characterization is an important complementary approach for identifying the presence of minor amounts of large inclusions in rubber.

scholarly journals An Image-Based Impact Test for the High Strain Rate Tensile Properties of Brittle Materials

2018 ◽  
Vol 183 ◽  
pp. 02042
Author(s):  
Lloyd Fletcher ◽  
Fabrice Pierron
Keyword(s):  
Tensile Strength ◽  
Elastic Modulus ◽  
High Strain Rate ◽  
Strain Rate ◽  
Stress Wave ◽  
High Strain ◽  
Brittle Materials ◽  
Test Method ◽  
Strain Rates ◽  
High Strain Rates

Testing ceramics at high strain rates presents many experimental diffsiculties due to the brittle nature of the material being tested. When using a split Hopkinson pressure bar (SHPB) for high strain rate testing, adequate time is required for stress wave effects to dampen out. For brittle materials, with small strains to failure, it is difficult to satisfy this constraint. Because of this limitation, there are minimal data (if any) available on the stiffness and tensile strength of ceramics at high strain rates. Recently, a new image-based inertial impact (IBII) test method has shown promise for analysing the high strain rate behaviour of brittle materials. This test method uses a reflected compressive stress wave to generate tensile stress and failure in an impacted specimen. Throughout the propagation of the stress wave, full-field displacement measurements are taken, from which strain and acceleration fields are derived. The acceleration fields are then used to reconstruct stress information and identify the material properties. The aim of this study is to apply the IBII test methodology to analyse the stiffness and strength of ceramics at high strain rates. The results show that it is possible to identify the elastic modulus and tensile strength of tungsten carbide at strain rates on the order of 1000 s-1. For a tungsten carbide with 13% cobalt binder the elastic modulus was identified as 516 GPa and the strength was 1400 MPa. Future applications concern boron carbide and sapphire, for which limited data exist in high rate tension.

Study of the Cr3+ sensitization and structural disorder effects on the Nd3+ laser action in Ca-gallogermanate-type codoped crystals

1997 ◽  
Vol 8 (1-2) ◽  
pp. 99-108 ◽  
Author(s):  
R. Balda ◽  
J. Azkargota ◽  
I. Iparraguirre ◽  
J. Fernández ◽  
M.A. Arriandiaga
Keyword(s):  
Laser Action ◽  
Structural Disorder ◽  
Disorder Effects

scholarly journals Statistical Analysis of the Tensile Strength of Carbon Nanotubes

2008 ◽  
Vol 41-42 ◽  
pp. 27-32 ◽  
Author(s):  
Chun Sheng Lu
Keyword(s):  
Carbon Nanotubes ◽  
Tensile Strength ◽  
Information Criterion ◽  
Strength Distribution ◽  
Data Sets ◽  
Weibull Statistics ◽  
Multi Walled Carbon Nanotubes ◽  
Simple Extrapolation ◽  
Walled Carbon Nanotubes ◽  
Optimal Strength

Two available strength data sets of single-walled and multi-walled carbon nanotubes are analysed, and the effects of sample sizes on their tensile strengths are investigated. A minimum information criterion is applied to determine the optimal strength distribution. The results show that, in contrast to a two-parameter Weibull distribution, lognormal distribution seems to be a more suitable choice. A simple extrapolation of classical Weibull statistics to nanoscales may result in overestimation on the tensile strength of carbon nanotubes.

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