System and method for remote full field three-dimensional displacement and strain measurements

摘要

A method and system for measuring full field deformation characteristics in three dimensions of a body upon which a pattern of visible marks has been applied. The method includes receiving images of the pattern of marks from at least two digital video cameras as the specimen deforms. A computer processor identifies the centroids of each of the two camera images of the body in a first frame, matches the centroids of the marks in the two images, and generates a three-dimensional representation of the centroids based on the two images, and repeats these steps for the images from the two cameras in a subsequent frame. The computer processor calculates the displacement vector between a three dimensional representation of the centroids and the subsequent three dimensional representation of the centroids, and calculates full field displacement and strain fields based on the displacement vector.

主权项

1. A computer-implemented method for measuring full field deformation characteristics in three dimensions of a deformable body upon which a visible dot pattern has been applied, the method comprising:
(a) receiving corresponding sequences of images from at least two imaging devices positioned facing the dot pattern at different angles, of images including a first frame taken before deformation of the body and a second frame taken after deformation of the body, of the dot pattern before and after deformation of the body; (b) for each image in the first frame, identifying the centroids of the dots with a computer processor, matching the centroids of the dots in an image from one imaging device to the centroids of the dots in a corresponding image from the other imaging device, and generating a three dimensional representation of the centroids of the pattern of dots from the two images; (c) repeat (b) for both images in the second frame; (d) matching the three dimensional representation of the centroids in the first frame to the three dimensional representation of the centroids in the second frame; (e) calculating the displacement vector of the centroids between the first frame and the second frame; and (f) calculating full field displacement in three dimensions based on the displacement vector of the centroids.