**4. PCE application to solving problems of superposition or/and cumulation of loadings**

The principle of critical energy generally refers to the effect of energy cumulation in a physical body, in connection with some phenomenon or process.

Load superposition means the simultaneous load actions upon the physical body. *Load* cumulation means successive load actions in time.

The discrimination between the superposition of effects and their cumulation is essential, especially if the effect of loading depends on the rate of applied load.
