FEATURE / THERMOPLASTIC UNIDIRECTIONAL TAPE Parameter Temp (°C) Baseline Temperature Autoclave Cycle 330 350 371 400 430 450 Rate Post-Processing Manufacturing Environment 385-415 385-415 385-415 385-415 385 385 385 + contamination 385 + 120 Dry Rate (mm/s) 6.35 6.35 6.35 6.35 6.35 6.35 1.27 2.54 6.35 12.7 12.7 + Anneal 12.7 12.7 12.7 Table 2. Induction weld parameter test results. Testing Single lap shear strength and crystallinity were used to evaluate the effects of different processing parameters and manufacturing environments on the joint strength. All testing was performed at Qarbon Aerospace. Lap shear testing was conducted according to ASTM D10026 . Differential Scanning Calorimetry (DSC) testing was conducted according to ASTM D34187 . ASTM D1002 Single Lap Shear Testing This test method covers the determination of the apparent shear strengths of welded thermoplastic Figure 2. Process parameter LSS comparison. composites when tested in a standard singlelap-joint coupon conditions6 under specified processing . This test method was primarily comparative but can be used as a discriminator of different processing variables on the strength and quality of the inductively welded joint. Single lap shear testing works well as an industry comparison and is a straightforward test to perform. It is not intended for design values since it is susceptible to peeling loads and not pure shear. For this preliminary screening, testing was conducted at room temperature ambient conditions using an Instron machine. All tests LSS (MPa) 39.1 ± 1.5 45.3 ± 1.9 46.4 ± 0.6 42.3 ± 2.7 42.4 ± 1.0 42.0 ± 0.9 43.4 ± 0.3 34.9 ± 2.6 38.9 ± 1.5 42.0 ± 0.9 36.9 ± 1.5 35.3 ± 4.2 36.9 ± 1.0 39.4 ± 1.3 42.6 ± 0.4 % Crystallinity 22.3 ± 2.5 14.5 ± 3.6 11.2 ± 0.8 10.5 ± 2.1 11.0 ± 2.1 11.3 ± 1.0 8.2 ± 2.5 15.3 ± 2.2 12.1 ± 1.8 10.9 ± 2.2 12.3 ± 1.7 27.2 ± 0.9 12.3 ± 1.4 10.5 ± 0.9 11.3 ± 2.5 30 | SAMPE JOURNAL | MARCH/APRIL 2022 www. sampe.orghttp://www.sampe.org