Surface Balance Laws of Linear and Angular Momenta and Cauchy's Stress Theorem


Department of Mechanical Engineering,Sharif University of Technology


Using Helmholtz's decomposition theorem, the laws of balance of linear and angular momenta are restated as surface integrals over the closed surface of an arbitrary subregion in a continuum. Newton's law of action and reaction and Cauchy's theorem for stress and couple-stress are proved as corollaries of these surface balance laws.