{'fraction_non_alphanumeric': 0.018444266238973536, 'fraction_numerical': 0.024859663191659984, 'mean_word_length': 4.804651162790698, '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}}
Surface Rotation Correction and Strain Precision of Wide-Angle 2D DIC for Field Use

9 The paper describes how 2D Digital Image Correlation is used on underneath surfaces of concrete 10 bridges with wide-angle lens camera during load testing, and how it has potential as a stop criterion in proof 11 loadings. 12 A method is proposed for correction of out-of-plane deflection including rotation of the surface. The 13 method is applied to laboratory tests, using well defined circular speckle patterns, as well as to a field tested 14 bridge (on raw concrete). The proposed correction corresponds to the level of pseudo strain, but is very 15 sensitive to precise surface deflection measurements. 16 In the laboratory tests, a strain precision of the wide-angle lens camera is compared to a regular lens 17 camera. The parametric study concludes that a Pattern Pixel Relation, in the interval from 4 to 9 pixels per 18 pattern circle diameter, provides the optimal precision regardless of the camera type. 19 The field tested bridge has less good precision compared to most parameter combinations of the 20 laboratory tests. Nevertheless, the field strain precision has potential for improvement based on learnings 21 from the laboratory tests. 22