{'fraction_non_alphanumeric': 0.018763796909492272, 'fraction_numerical': 0.0, 'mean_word_length': 5.170068027210885, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
DSPI applied to rubber viscoelastic behavior at low stresses study

A thin rubber plate is circumferentially clamped and centrally loaded with a small constant force. The behavior of this elastic membrane is studied through an out-of-plane sensitive Digital speckle-pattern interferometer. The surface deformations of the plate are revealed by a developed program, realizing the phase determining method of Spatial heterodyning. Simulated noisy speckle patterns are used to test the possibilities of the software. The removal of an arising tilt effect, due to a non-whole number of carrier fringes in the analyzed pattern, is shown and discussed. Experimental results are presented for the rubber surface deflection in several consecutive moments during the application of the force, and after its removal. Trajectories of surface points are plotted. A subtle effects of non-linear behavior are visualized.