Stress is an engineering term used to describe the internal loads between particles of material when it is under load. The units of this measurement are psi or N/m^2 but should not be confused with other measurements that use these units such as fluid pressure. In structural engineering, the general process is to calculate the stress in a body and compare it to the allowable stress for that material. Allowable stress of the material is taken from the yield strength or from a specific code.
