Tensile stress is measured in units of force per unit area. The unit is newton per square meter (N/m^2), kilogram (force) per square centimeter (kg/cm^2), or pascal.
The most commonly used unit of stress is the pascal, which is a force of 1N exerted on a unit area.
- 1 Pascal = 1 N/m2
However, it is a fairly small unit for most engineering problems, so it is convenient to work with multiples of the pascal: the GPa, and the MPa.
- 1 MPa 106 N/m2
- 1 GPa 109 N/m2
A material’s ultimate tensile strength (UTS) is the force per unit area at which it breaks in two. Tensile stress is that type of stress in which the two sections of material on either side of a stress plane tend to pull apart or elongate. The capacity of a material or structure to withstand loads tending to elongate is known as ultimate tensile strength (UTS). Ultimate tensile strength is measured by the maximum stress a material can withstand while being stretched or pulled before breaking. In the study of the strength of materials, tensile strength, compressive strength, and shear strength can be analyzed independently. Because tensile and compressive loads produce stresses that act across a plane in a direction perpendicular (normal) to the plane, tensile and compressive stresses are called normal stresses.
Strain is a dimensionless quantity that expresses a proportional dimensional change (intensity or degree of the distortion) and is measured as the total deformation (elongation) per reference length of material due to some applied stress.