MCDSG Analysis from Sample HBR06-20 (IMAGE) Science China Press Caption Principle strain state at fault tips in first stage of crack propagation. For a clear observation, this type of strain map is all magnified by 200 times compared with measurement value in this paper. (a) Strain field as wing crack growth at the upper tip; (b) strain field as wing crack growth at the lower tip. Credit © Science in China Press Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.