FEATURE / THERMOPLASTIC COMPOSITES FROM ADDITIVE MANUFACTURING Figure 4. Test set-up of the fracture toughness tests: (a) Double cantilever beam test and (b) Endnotch flexural testing (photos provided by UD-CCM). (a) (b) at University of Delaware (UD-CCM) was used to apply load through the tensile fixtures. A traveling camera was placed in front of the test coupons to record the crack opening. The dimensions of the DCB coupons are 120 mm in length, 20 mm in width, 3 mm thickness, and the initial crack was 50 mm. The ENF tests were done with a three-point flexural test fixture as shown in Figure 4 (b), and the coupon dimensions are 130 mm in length, 20 mm in width, 3 mm thickness, and an initial crack of 30 mm. Impact and Compression After Impact (CAI) Tests To examine the impact resistance and the damage tolerance of the DED printed materials, QI coupons were tested with the ASTM D7136 falling weight impact and ASTM D7137 compression after impact tests. The coupon dimensions were 150 mm × 100 mm × 5 mm. The coupons are impacted with 5.3 kg projectile from a height of 694 mm. The impact energy was 6.67 J/mm. The coupons were Ultrasonic C-scanned with a 5 MHz probe before and after the impact test. The damaged area, dent depth and the energy absorbed were determined after the impact tests. Compression test with the fixture as specified Figure 5. Representative micrograph of (a) unidirectional (void content =0.02%) and (b) quasi-isotropic parts (void content = 0.63%) from AREVO DED process. (a) (b) 32 | SAMPE JOURNAL | S E P T E M B E R /O C TO B E R 2 0 1 9 w w w. s a m p e . o r ghttp://www.sampe.org