stresses and strains

Stresses refer to the internal forces per unit area within a material when it is subjected to external loads, such as tension, compression, or shear. Strains describe how much the material deforms or changes shape as a result of these stresses, usually expressed as a percentage or ratio of the original size. In essence, stress is the "force trying to change" the material, while strain is the "actual change" that occurs. Understanding the relationship between stress and strain helps engineers ensure structures can withstand forces without deforming or failing.