Engineering mechanics is the branch of mechanics, which deals with the implementation of the basic statements of mechanics in applied problems. Here, among other things stresses and strains in deformable bodies are determined or motions are studied, often being intuitive considered as solids. Engineering mechanics is closely related to mathematics (especially analysis and numerical solution methods). At the same time there are interactions with branches of physics, with materials science, and with other engineering sciences (eg. fluid mechanics and thermodynamics).
The theoretical foundation is given by the geometric description of motions and deformations, by the definition of internal and external stresses, as well as the formulation of balances or in the simplest case, of conservation laws. The focus here is on basic (universal) statements on mass, momentum, angular momentum, energy, and entropy. The fact known from experience, that different materials and matters show a differing response to stress, is expressed in specific approaches for the constitutive relations. This area is increasingly becoming the focus of research.