Tensile strength refers to the maximum tensile stress that the sample can bear before being pulled off, which is expressed by the symbol σb and the unit is MPa.
σb=Fb？ /? A0 Fb: the maximum tensile force before the sample is pulled away, n.
σb represents the resistance of the material to the maximum uniform plastic deformation. The ratio of σs to σb is called yield ratio. The smaller the yield ratio, the higher the reliability of the parts when working, because overload will not break immediately. However, if the yield ratio is too small, the effective utilization rate of material strength will decrease. σb is also the main parameter of design and material selection.
Extended data
Tensile strength, elastic limit and yield strength are often used as standards for the strength of metal materials, which are measured by stress. The internal force per unit section is called stress, which is expressed by the symbol σ. Internal force refers to the internal resistance that prevents the material from deformation when it is deformed by external force.
1, the elastic limit refers to the maximum stress that the sample can bear when it is completely elastically deformed, which is expressed by the symbol σe and the unit is MPa.
Calculation formula: σe=Fe? /? A0
Fe: the maximum tensile force when the specimen is completely elastically deformed, n;
A0: original cross-sectional area of the sample, mm2.
2. Yield strength refers to the stress that the specimen can continue to elongate (deform) without increasing the force (keep the same) during the tensile process, which is expressed by the symbol σs and the unit is MPa.
σs=Fs？ /? A0
Fs: tensile force when the sample yields, n.
References:
Southeast University -GB\T228 2002 Metal Materials