DYNAMIC RADIOGRAPHY FOR NONDESTRUCTIVE TESTING.

Dynamic radiography is meant to include all analyses of the modulated component of a penetrating radiation field emerging from an optically opaque object to obtain information regarding the orientation and dynamical state of internal structures. This chapter describes the general ideas embodied in dynamic radiography techniques, and further describes the ideas by developing details of a specific case, namely the ″vibrating string″ , which is the simplest example of continuum mechanics. The description progresses from the analysis of a radiation kymograph (time record) of a single-image element to the formation of dynamic images of the whole vibration system.