Bar (unit) Bar (unit) The bar is a metric unit of pressure, but is not approved as part of the International System of Units (SI). It is defined as exactly equal to 100,000 Pa, which is slightly less than the current average atmospheric pressure on Earth at sea level. The bar and the millibar were introduced by the Norwegian meteorologist Vilhelm Bjerknes, who was a founder of the modern practice of weather forecasting. The International Bureau of Weights and Measures (BIPM) lists the bar as one of the "non-SI units [that authors] should have the freedom to use", but has declined to
Stress–strain curve these two relationships, a relationship of σ=kεἕ can be found. However, as real stresses and strains do not occur uniaxially, considerations for multiaxial stresses must be added to this relationship to model real stresses. This stress is called the tensile stress because every part of the object is subjected to tension. The SI unit of stress is the newton per square meter, which is called the pascal. 1 pascal = 1 Pa = 1 N/m Now consider a force that is applied tangentially to an object. The ratio of the shearing force to the area A is called the shear