Research on Mode I Fracture Properties of Bamboo Scrimber Based on DIC Technology

Abstract

To promote the application of bamboo scrimber (BS) in the construction field, it is necessary to study the fracture properties concerning its structural design and reliability analysis. In this paper, the Mode I fracture properties of BS were investigated based on the digital image correlation (DIC) technique. The experimental phenomena and strain field changes corresponding to each stage were analyzed, and the failure mode of the specimen was analyzed from both macroscopic and microscopic perspectives. Using the DIC technique to analyze the corresponding real-time crack length, the real compliance-crack length (C-a) curve was obtained, and then the calculation method of strain energy release rate (GI) was obtained and compared with the results of four common calculation methods. The modified compliance calibration (MCC) method, which is closest to the real value and is not limited by equipment, was chosen as the calculation method of strain energy release rate in this paper. The effects of three variables on the critical strain energy release rate (GIC) were analyzed, and the recommended specimen size for testing Mode I fracture toughness of BS is proposed as thickness (B)≥30 mm and height (W)≥50 mm. Finally, the critical strain energy release rate for Mode I fracture of BS was calculated to be GIC=1.18 N/mm, and the corresponding critical stress intensity factor was KIC=81.88 MPa·mm1/2.