Burding stress is the maximum stress that a material can withstand under tension before its cross section "Section (geometry)") contracts significantly.[1]​[2]​.

The breaking stress is usually obtained by performing a tensile test and recording the stress as a function of strain (or elongation); The highest point on the stress-strain curve is the failure stress. It is an intensive property; Therefore, its value does not depend on the size of the sample, but on factors, such as preparation, the presence or absence of surface defects, and the temperature of the environment and the material.

Breaking stresses are rarely considered in the design of ductile elements, but are nevertheless very important in the design of brittle elements. They are tabulated for the most common materials such as alloys, composite materials, ceramics, plastics, and wood.

Breaking stress is defined as a stress that is measured in units of force per unit area. For some non-homogeneous materials it is indicated as a force or a force per unit thickness. In the international system, the unit is the pascal "Pascal (unit)") (Pa) (or a multiple thereof, often the megapascal (MPa), using the prefix Mega); or, equivalent to the Pascal, Newton "Newton (unit)") per square meter (N/m²).

Ductile materials

Many materials present elastic behavior, which is defined by the existence of a linear relationship between stress and deformation, as shown in the figure up to point 2, in which the deformations&action=edit&redlink=1 "Deformation (engineering) (not yet written)") are completely reversed when the load or acting force is eliminated; that is, the specimen loaded by a tension in the elastic region will stretch, but will take its original shape and size when the load is removed. After the linear region, in ductile materials, such as steel, the deformations are plastic. A specimen that has been plastically deformed will not assume its original shape and size when the load is removed. It should be noted that in this case a part of the deformation will be recovered. In many uses, plastic deformation is unacceptable, and therefore is identified as a limiting factor in design.

After the elastic limit point, ductile metals present a strain-induced hardening zone, in which the stress increases with increasing strains, and the specimen begins to develop a necking, in which the cross section of the specimen decreases due to plastic flow. In a sufficiently ductile material, when the necking is appreciable, an inversion is observed in the engineering stress-strain curve (curve A); This is because the is calculated using the cross-sectional area of ​​the original specimen before necking occurred. The inversion point corresponds to the maximum stress on the engineering stress-strain curve, and the engineering stress coordinate at this point is called the ultimate stress at failure, mentioned in point 1.