Fracture resistance measurement of fused deposition modeling 3D printed polymers

A method is presented to characterize the fracture resistance and interlayer adhesion of fused deposition modeling (FDM) 3D printed materials. Double cantilever beam (DCB) specimens of acrylonitrile butadiene styrene (ABS) were designed and printed with a precrack at the layers' interface. The DCBs were loaded in an opening mode and the load-displacement curves were synchronized with the optical visualization of the crack tip to detect the critical load at the crack initiation. A finite element model, coupled with J-integral method and fracture surface analysis was then developed to obtain the apparent fracture resistance (Jcr,a) and the interlayer fracture resistance (Jcr,i), as a measure of the interlayer adhesion. The maximum Jcr,i was measured to be 4017 J/m2, a value close to the fracture resistance of bulk ABS. Both Jcr,a and Jcr,i increased with the printing temperature. This method can find a great importance in the structural applications of printed materials.