Caustics and quasiconformality. A new method for the evaluation of stress singularities

The relation between the optical mapping of caustics and the function-theoretic concept of quasiconformality is investigated. Utilizing this relation, an experimental technique for the evaluation of the order of singularity for singular elastic fields was developed. In particular, the mapping of an infinitesimal circle onto an infinitesimal ellipse by means of the (pseudo)caustics, provides the unique possibility of directly evaluating the stress singularity by experimental means.