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 situations. One can resist and live normal life till the stresses encountered are less intense than one's strength. But one could not resist and may injured and unable to continue routine life when stresses are more intense than one's strength. However one will regain the strength with due time and continue normal life. So break down is temporary only like resistance of lightening arrestors.

All persons have mental strength to handle complex situations. They are subjected to mental stress because of various problems in the life. One with strong mental strength can handle situations well but one with weak mental power may confuse, loose mental control or have permanent loss due to suicide. However appropriate treatment at right stage can reinstate normalcy to some extent avoiding total loss.