Stress and Strength
Stress and Strength Insulating materials used in electrical equipment have dielectric strength. It is subjected to dielectric stress during its service in electric circuit. Material is safe and perform as insulation till dielectric stress (alias electro static field or potential gradient) is lower than its strength during service. But may breakdown when service stress imposed is more than material strength. Afterward it cannot perform as insulator and discarded. Materials used in structure have tensile, compressive and shearing strength. It is subject to one or more of stresses due to load in different working conditions. Component is safe and continue as active member of structure till stresses are lower than respective strength. But it may break, crimp or rupture when working stress exceeds the respective strength. Such failed component is no more useful in structure. All persons have physical strength. They are subject to external physical stress under different situatio...
