Fundamental Conservation Principles
The fundamental principles of continuum mechanics are those that deal with the conservation of some physical quantity. Conservation means that these quantities cannot change over time, unless an external force intervenes. These conservation principles, as they are often called, are postulated for all material continua, irrespective of the material’s constitution and geometry, and result in equations that must always be satisfied. They deal with mass, linear and angular momenta, energy and entropy. The conservation principles are also valid for all bodies subject to thermomechanical effects.