Paper number 1111

EFFECTS OF STACKING SEQUENCE ON THE TRANSVERSE CRACKING IN QUASI-ISOTROPIC INTERLEAVED CFRP LAMINATES

Satoshi Kobayashi¹ , Nobuo Takeda² , Shinji Ogihara³ and Akira Kobayashi³

1Graduate Student, Takeda Lab., CCR, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
2Department of Aeronautics and Astronautics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
3Department of Mechanical Engineering, Science University of Tokyo, 2641 Yamasaki, Noda, Chiba 278-8510, Japan

Summary

Transverse crack behavior in quasi-isotropic interleaved CFRP laminates was observed by an optical microscope and a soft X-ray radiography system. Seven symmetric laminates composed of the same combination of ply orientations were tested to clarify the effect of stacking sequence on transverse crack behavior in 90° plies. The thickness of 90° plies and the modulus of adjacent plies were found to be most effective on the transverse cracking. To model the experimental results, damage mechanics analysis was used. The predictions of transverse crack evolution based on both energy and average stress criteria were compared with the experimental results. The validity of the present analysis was confirmed. The advantage of this analysis was its applicability to general laminate configuration, once the critical values were determined.

Keywords

CFRP, qasi-iotropic lminates, tansverse cack, sacking squence, dmage mchanics, energy release rate.