Dynamic crack initiation and growth in cellulose nanopaper

Cellulose nanopaper (CNP) made of cellulose nanofibrils has gained extensive attention in recent years for its lightweight and superior mechanical properties alongside sustainable green attributes. The characterization studies on CNP at the moment have generally been limited to tension tests. In fact, thus far there not any report crack initiation growth behavior, especially under dynamic loading conditions. this work, self-assembled CNP, from filtration CNF suspension, are studied using a full-field optical method. Dynamic behaviors time-resolved fracture parameters quantified Digital Image Correlation technique. challenge associated with thin strip overcome by an acrylic holder wide pre-cut slot bridged edge-cracked CNP. ultrahigh-speed digital photography is implemented map in-plane deformations during pre- post-crack regimes including growth. Under stress wave conditions, macroscale occurs surprisingly high-speed (600–700 m/s) microscopically fibrous material. measured displacement fields conditions analyzed extract intensity factors (SIF) energy release rate (G) histories. results show that SIF range 6–7 MPa m1/2, many engineering plastics. Furthermore, values increase propagation both low- high-strain rates, demonstrating resistance valuable structural applications.Graphical abstract