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Characterization Techniques
Published in Chandan Das, Sujoy Bose, Advanced Ceramic Membranes and Applications, 2017
Flexural strength is a material property, defined as the stress in a material just before it yields in a flexure test. It is also known as modulus of rupture, bend strength, or fracture strength. The transverse bending test is most commonly used: A specimen with either a circular or rectangular cross section is bent until fracture or yielding takes place, using either a three-point or four-point flexural bend test technique. The three-point bend test is more suitable for ceramics compared to the four-point bend test. As in the former case, the specimen requires minimum size, which increases the measured value of flexural strength.
Design and installation of monitoring wells
Published in Neal Wilson, Soil Water and Ground Water Sampling, 2020
Materials used in the construction of monitoring wells must have adequate tensile, compressive, and collapse strengths. Tensile strength is the greatest longitudinal (pulling lengthwise) stress the material can sustain before it pulls apart. Compressive strength is the maximum compressive stress (squeezing lengthwise) that can be applied before the material deforms. Collapse strength is perpendicular to the major axis, and is defined as the ability of the material to resist collapse to any external force during and after installation. Collapse strength is proportional to the cube of the wall thickness.
Design Properties of Materials
Published in Robert L. Mott, Joseph A. Untener, Applied Strength of Materials, 2016
Robert L. Mott, Joseph A. Untener
Many metals do not exhibit a well-defined yield point like that in Figure 2–3. Some examples are high-strength alloy steels, aluminum, and titanium. However, these materials do in fact yield, in the sense of deforming a sizable amount before fracture actually occurs. For these materials, a typical stress–strain diagram would look like the one shown in Figure 2–4. The curve is smooth with no pronounced yield point. For such materials, the yield strength is defined by a line like M–N drawn parallel to the straight-line portion of the test curve.
Tensile strength and elongation of selected Kenaf fibres of Ghana
Published in Cogent Engineering, 2023
George Ansong, Yesuenyeagbe A.K. Fiagbe, Antonia Y. Tetteh, Francis Davis
The tensile strength can be defined as the maximum stress that a material can bear before breaking when it is allowed to be stretched or pulled. The tensile strength of the fibre strand was obtained from the test result and found to range from 734.53 MPa for EB31 to 1365.14 MPa for HN11. For the genotypes, the tensile strengths are found to be 734.53 MPa (EB31), 1292.37 MPa (TN11), 1241.53 MPa (EN31), 979.35 MPa (PN11) and 1365.14MPa (HN11). The tensile strength for the EB31 genotype ranges from 242.03 MPa to 1450.27 MPa; that of TN11 ranges from 630.28 to 2300.95 MPa; EN31 from 912.47 MPa to 2076.63 MPa; PN11 from 388.25 MPa to 2302.48 MPa and for the HN11 genotype, it ranges from 405.03 MPa to 2624.89 MPa. The tensile strength result is presented in Figure 5.
Bioinspired nacre-like GO-based fiber with improved strength and toughness by staggered layer structure regulation and interface modification
Published in Mechanics of Advanced Materials and Structures, 2022
Li Feng, Yongcun Li, Yunbo Luan, Zhangxin Guo, Feng Xu, Xingyuan Zhang
In this paper, the GO-based artificial nacre composite fiber was prepared by wet spinning method, and its mechanical behavior was studied by mechanical theory and finite element analysis. It shows that by adjusting the mass ratio of TPU to GO, the GO-TPU fibers with different micro-laminated structures can be obtained. These fibers had different stress distribution and load transfer mechanisms. By optimizing the layered structure, the tensile strength and toughness of the material can be improved. In addition, the influence of interfacial bonding on the mechanical properties of materials was also studied. It shows that the interface condition between GO and TPU can be improved by adding a certain amount of CNTs to the GO-TPU composite fiber. Further analysis shows that the combination of CNTs and GO sheets can optimize the internal load transfer efficiency, then enhance the mechanical properties of the fiber composite materials. These results may provide useful guidance for the exploration of the internal structure optimization strategy of biomimetic fiber materials and the improvement of mechanical properties.
Assessment Techniques for Studying the Effects of Fire on Stone Materials: A Literature Review
Published in International Journal of Architectural Heritage, 2020
Edite Martinho, Amélia Dionísio
The mechanical strength of natural stones is a parameter that is also used to assess their quality. It is mainly controlled by their heterogeneity and fabric, the individual properties of the rock-forming minerals are less relevant (Siegesmund and Durrast 2011). Mechanical strength corresponds to a material´s capacity to support an applied stress without failure or plastic deformation. The applied stress may be tensile, compressive or shear. Uniaxial compressive strength is the most common parameter used to evaluate stone quality. Currently, ultrasound is one of the most important non-destructive tests for assessing stone decay on historical buildings and artwork. Stones are elastic media, so when a stress is applied or withdrawn abruptly, the corresponding deformation propagates outwardly as elastic waves (Sharma 1997). The main elastic waves are “compressional/dilatational” (P-waves) or “shear” (S-waves) waves, which are expressed by movement equations in terms of dilatational and rotational strains (Richter 1958). Thus, the P- and S- waves velocities (VP and VS, respectively) are related to a stone’s elastic moduli and density (Sharma 1997). While P-waves are used for most applications, measuring S-waves is essential for calculating elastic moduli (bulk modulus, K, Young’s modulus, E, Poisson’s ratio, σ, and shear modulus, µ), which are also related to the mechanical characteristics of the materials.