Gravitational Stresses Determined Using Immersion Techniques

Abstract : This paper deals with a generalization of an immersion analogy suggested by Biot. A simple general proof of the analogy is given. Applications are described to two-dimensional problems (using urethane rubber specimens immersed in thallium formate) and to three-dimensional problems (using epoxy models immersed in mercury). Two- and three-dimensional photoelasticity are used to determine stresses. The increase in response obtained by using the immersion technique permits the solution of a number of new problems where gravitational stresses play an important role, for example, in dams and in solid propellant rocket grains. (Author)