FIXATION OF 3-DIMENSIONAL STATES OF DEFORMATION IN POLYMERS BY IONIZING-RADIATION - SEARCH FOR NEW POLYMERIC MATERIALS

The fixation of three-dimensional states of deformation in polymers al lows the analysis of ''special states'' of elastic stresses even in th e interior of complex constructional units and machine parts. This is the reason for the fact that in spite of the development of modem expe rimental methods of the analysis of deformation, which are in general restricted to the deformation of the surface of the bodies, the classi cal ''photoelasticity'' is still. an adequate procedure for solving te chnical problems. However there are several restrictions on the applic ability of the presently used procedures. A potential way to overcome these restrictions is the use of ionizing radiation, which in several polymeric materials causes a more or less perfect fixation of three-di mensional states of deformation. The search for suitable polymers incl udes the modification of well-known materials like epoxy resins as wel l as the application and development of materials not yet used in this field of engineering. Preliminary results of the search for such new materials are presented In selected polymers the stress-optical consta nt f(sigma) (S) typically increases with dose, whereas the optical cre ep behaves ambiguous on irradiation.