Experimental investigation of low-velocity impact behavior and CAI on composite laminates by discrete interleaved toughening

Abstract

A novel damage tolerance design method of discrete interleaved toughening for laminated composite was proposed. In this paper, discrete thermoplastic Polyamide-6,6 (PA 66) films were deployed at between the selected adjected layers, and three toughening dimensions were considered. Besides, three impact positions of specimens were tested under 5 J, 10 J, and 15 J, respectively. The impact behavior and compression after impact (CAI) of specimens were discussed and compared. Experimental results showed that delamination damage was suppressed in the process of propagation outwards across the toughened region, and the path of delamination crack propagation was changed and swerved. Therefore, the delamination damage projected area (DDPA) of all specimens were reduced by 21.09%–62.85%, compared with the non-toughened plate (base plate). In addition, the finding demonstrated that CAI strength is influenced by the delamination position and DDPA. The proposed method could improve the CAI strength by suppressing delamination and swerving the propagation path of delamination. Moreover, the CAI strength of all toughened plates were improved by 16.35%–61.94% in contrast to the related base plates.

Keywords:

• Composite laminates
• discrete interleaving
• delamination
• damage mechanics
• impact behavior
• CAI strength

Author contributions

Cong Zhang: Data curation and writing—original draft. Xitao Zheng: supervision. Keyu Zhu: methodology and software. Jing Peng: visualization and investigation. Zhibang Wang: investigation. Leilei Yan: conceptualization, funding acquisition, and writing—review and editing.

Disclsoure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Aeronautical Science Foundation of China (201909053001), Fundamental Research Funds for the Central Universities (D5000220029), Fundamental Research Funds of Shaanxi Key Laboratory of Artificially-Structured Functional Materials and Devices (AFMD-KFJJ-21212).