Superposition and/or cumulation of loads in the case of linear behavior of matter, solved by a monodisciplinary or interdisciplinary approach

In the various chapters of science and especially in engineering sciences, there are many cases of superposition and/or cumulation of loads or their effects. The way one can solve such problems depends on the behavior of the material under load. The paper deals with the linear behavior of matter in which case the principle in physics, mechanics, mechanical engineering, electrical engineering, perfect gas statics, fluid flow etc. Case involving a monodisciplinary approach are separated from those involving an interdisciplinary approach to practical solutions. The interdisciplinary approach is also used to analyze the inverse problem where a certain load produces two or more effects, including the thermal one. One has found that, in the case of linear behavior, no synergistic effects can be detected. On that account, one can claim that, in the case of nonlinear behavior, solving the problems of superposition and/or cumulation of loads or their effects can now be done only by applying the principle of critical energy that allows – among other things – the introduction of the influence of matter damage, of the thermal effect, of the rate of load variation etc.