Direct Assessment of Mode I Fracture Properties in Silver Fir Using MMCG Specimen and Digital Image Correlation

In this study, we investigate the cracking behaviour of softwood species using the MMCG fracture test. Our primary objective is to directly measure crack length propagation in mode I loading and the associated fracture parameters. To achieve this, we employ the Arcan system to apply load to the specimen. We used Digital Image Correlation (DIC) to measure displacement and strain fields ahead of the advancing crack. Fracture properties were determined using the compliance method, providing an estimate of the critical strain energy release rate for mode I. Two different methodologies were employed and compared to determine crack length during the tests. A comparison of the average values of critical strain energy release rate among the reported values in the literature for other temperate species demonstrated a consistent pattern. This consistency offers valuable insights into understanding the fracture behaviour of Silver Fir.