An Experimental Investigation into Fracture Resistance of Carbon Fibre Sheet Moulding Compound

• First End Loaded Split (ELS) tests of Carbon Fibre Sheet Moulding Compound (CF-SMC) • First Mode I R-curve of CF-SMC material reported using Double Cantilever Beam (DCB) tests. • Mode I R-curve behaviour of CF-SMC observed to be caused by fibre bridging. • Mode II fracture behaviour of CF-SMC material explained through crack migration. Carbon Fibre Sheet Moulding Compound (CF-SMC) is an attractive material due to its good formability and green credentials. However, there is a lack of reliable fracture data, posing challenges when analysing CF-SMC materials which already have built-in randomness. Fracture Resistance curves (R-curves) and their variability have not been reported before for CF-SMC materials. This knowledge gap in the literature is addressed through Double Cantilever Beam (DCB) and first End Loaded Split (ELS) tests on CF-SMC. This work also explains the toughening mechanisms in CF-SMC materials during interlaminar fracture. Under Mode I, the toughening mechanism is fibre bridging while it is crack migration for Mode II. The new R-curve data provides new insights into the interlaminar fracture behaviour of CF-SMC materials and can be used as invaluable inputs for their failure analyses.