PSI - Issue 80

Hideaki Katogi et al. / Procedia Structural Integrity 80 (2026) 462–470 Hideaki Katogi / Structural Integrity Procedia 00 (2019) 000–000

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property of biocomposite material using poly(lactic acid) resin was higher than that of biocomposite material using shellac resin at all test speed conditions. Their results implied that the tensile properties of biocomposite materials using poly(lactic acid) and shellac resins were affected by loading speed. Figures 5 and 6 show fracture morphologies of biocomposite materials using poly(lactic acid) and shellac resins. The residual poly(lactic acid) resin of fracture morphologies of biocomposite material using poly(lactic acid) resin was found after tensile tests at all loading speed conditions. But fracture morphology of biocomposite material using poly(lactic acid) resin at 10 mm/min was similar to that of biocomposite material using poly(lactic acid) resin at 100 mm/min. Also, the residual shellac resin of fracture morphology of biocomposite material using shellac resin was found after tensile test at all loading speed conditions. But the long fiber-pullout on fracture morphology of biocomposite material using shellac resin was found after tensile test at 100 mm/min. Generally, matrices have strain rate dependence because poly(lactic acid) and shellac resins as matrix are biopolymer. Above mentioned, a single flax yarn as reinforcement has spiral structure. The flax fiber mainly consists of cellulose. But tensile strength of biocomposite material using poly(lactic acid) was noticeably higher than

Fig. 3. Effect of tensile property of a single flax yarn (a) Tensile strength; (b) Young’s modulus.

Fig. 4. Effect of loading speed on tensile properties of biocomposite materials using poly(lactic acid) and shellac resins (a) Tensile strength; (b) Young’s modulus.