Tensile strength definition

By definition, a brittle material does not fail in shear failure oeeurs when the largest prineipal stress reaehes the ultimate tensile strength, Su. Where the ultimate eompressive strength, Su, and Su of brittle material are approximately the same, the Maximum Normal Stress Theory applies (Edwards and MeKee, 1991 Norton, 1996). The probabilistie failure eriterion is essentially the same as equation 4.55. 

Definitive studies of composite material tensile strength from a micromechanics viewpoint simply do not exist. Obviously, much work remains in this area before composite materials can be accurately designed, i.e., constituents chosen and proportioned to resist a specified tensile stress. 

As for the tenacity, which describes the fiber s resistance to the action of the tensile force, the quantitative index assumed most often is the tensile strength (crj (cN/tex). For the quantitative assessment of tenacity an index of mechanical long life (t) is used, proposed by Zurkow and Abasow [46,47]. This index defines the time after which, when applying a definite tensile strength and a definite temperature, the fiber breaks. 

The maximum in the curve denotes the stress at yield av and the elongation at yield v. The end of the curve denotes the failure of the material, which is characterized by the tensile strength a and the ultimate strain or elon gation to break. These values are determined from a stress-strain curve while the actual experimental values are generally reported as load-deformation curves. Thus (he experimental curves require a transformation of scales to obtain the desired stress-strain curves. This is accomplished by the following definitions. For tensile tests ... 

Polymerization products with internal plasticization have the advantage that there is no migration or efflorescence of the plasticizer on storage. On the other hand, the mechanical properties—above all, flexibility at low temperatures—are decreased in comparison with the products with low molecular plasticizers. This is because mobility in the solvatized molecules is diminished. The same refers to tensile strength, which is often decreased with internally plasticized polymers. In this respect they are inferior to externally plasticized products, which also have an advantage in that type and quantity of plasticizer can be varied widely. Internally plasticized products must have a definite ratio of components. These are reasons why combinations of both types of plasticizers are preferred. 

The detailed work of Bernd (ref. 15-17) and other investigators has also shown that the tensile strength of water is set by the gas nuclei (i.e., microbubbles) present in the water. (Accordingly, the earlier-mentioned definition of the tensile strength of a liquid can be restated as the minimum tensile stress at which the gas nuclei in the liquid start to explode . This property is also often referred to as the cavitation susceptibility (ref. 57).) Using specially constructed sonar transducers, the behavior of gas nuclei was followed by Bernd by measuring tensile strength. Surface... 

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