Experimental study of inelastic strain patterns in a model of a tube-plate ligament using an interferometric moiré technique

A sensitive moiré interferometer has been developed for measuring elasto-plastic strain distributions. No rigid connection with the specimen was required, and the fringe patterns could be seen by eye as loading progressed. The system has been applied to the measurement of strain patterns in a stainless-steel model of a tube-plate ligament. The model was loaded in tension and in bending, with the eventual aim of measuring strain-intensification factors which could be used as basic design data.