摘要
A special X-radiography,used in obtaining the deformed specimen grating in in-plane moire method is introduced.The density of gridline is up to 50 lines / mm.This method is suitable not only for the copy of grating in fiat surface but also for that in curved surface.From unfolding the copy and superposing it with a reference grating,the moire effect arises.By processing this moire fringes with the digital image processing unit, the strain distribution would be obtained.Furthermore,the u-and v-displacement fields could be separated by the optical processing of this copy.The measurment sensitivity and accuracy become better simultaneously because of the fringe multiplication.Thus,this method makes it possible to measure the elastic-plastic strain precisely in any developable curved surfaces,for example, the surface of shaft,rotary-wing,cylindrical shell and cone shell etc.
A special X-radiography,used in obtaining the deformed specimen grating in in-plane moire method is introduced.The density of gridline is up to 50 lines / mm.This method is suitable not only for the copy of grating in fiat surface but also for that in curved surface.From unfolding the copy and superposing it with a reference grating,the moire effect arises.By processing this moire fringes with the digital image processing unit, the strain distribution would be obtained.Furthermore,the u-and v-displacement fields could be separated by the optical processing of this copy.The measurment sensitivity and accuracy become better simultaneously because of the fringe multiplication.Thus,this method makes it possible to measure the elastic-plastic strain precisely in any developable curved surfaces,for example, the surface of shaft,rotary-wing,cylindrical shell and cone shell etc.
