By using monotonic and cyclic loading tests, the Poisson curves along the fiber bundles directions of a 2D-C/SiC composite were obtained during various axial tensile and compressive loading processes. And the effects of axial damage evolution process on the Poisson effect of composite were studied. The results show that composite shows significant negative Poisson's ratio behaviors with increasing tensile damage during loading process, but the Poisson's ratio behaviors become almost linear and positive when the damage evolution process stops. In addition, the Poisson effect becomes weaker with increasing damage degree within composite. The SEM (scanning electron microscope) analysis results of fractured surfaces on tensile specimens indicate that, during tensile damage evolution process, the matrix cracks and interface debondings occurring along the loading direction will generate vertical extension deformation on composite, which is large enough to cover up the transverse elastic Poisson contraction caused by applied tensile load, so 2D-C/SiC composite shows significant negative Poisson' ratio behaviors. And the weaker Poisson effect of composite is mainly caused by the increasing discontinuity of composite, which is caused essentially by increasing cracking damage during tensile damage evolution process.
LU G F , QIAO S R , XU Y . Progress in research on interface layer of continuous fiber reinforced ceramic matrix composites[J]. Journal of Materials Engineering, 2014, (11): 107- 112.
WANG B , WU Y B , HUANG X P , et al. In-plane shear performance statistics of 2D-C/SiC composites and its B-basis value of strength[J]. Journal of Materials Engineering, 2019, 47 (1): 131- 138.
VANSWIJGENHOVEN E , BIEST O V . A model for the transverse strain response of unidirectional ceramic matrix composites during tensile testing[J]. Materials Science and Engineering: A, 1998, 250 (2): 222- 230.
VANSWIJGENHOVEN E , BIEST O V . The relationship between longitudinal stress and transverse strain during tensile testing of unidirectional fiber toughened ceramic matrix composites[J]. Acta Materialia, 1997, 45 (8): 3349- 3362.
HABIB F A , TAYLOR R A J , COOKE R G , et al. Fatigue damage in SiC/CAS composites[J]. Composites, 1993, 24 (2): 157- 165.
CAMUS G , GUILLAUMAT L , BASTE S . Development of damage in a 2D woven C/SiC composite under mechanical loading: Ⅰ mechanical characterization[J]. Composites Science and Technology, 1996, 56 (12): 1363- 1372.
WEIGEL N , KRÖPLIN B , DRINKLER D . Micromechanical modeling of damage and failure mechanisms in C/C-SiC[J]. Computational Materials Science, 1996, 16 (1/4): 120- 132.
WANG Y Q , ZHANG L T , CHENG L F , et al. Characterization of tensile behavior of a two-dimensional woven carbon/silicon carbide composite fabricated by chemical vapor infiltration[J]. Materials Science and Engineering: A, 2008, 497 (1/2): 295- 300.
李俊. 二维C/SiC复合材料非线性本构关系研究[D]. 西安: 西北工业大学, 2014.
LI J. Research on the nonlinear constitutive relationship of 2D C/SiC composites[D]. Xi'an: Northwestern Polytechnical University, 2014.
TAKEDA N , KIRIYAMA M . Matrix crack evolution in SiC fiber/glass matrix cross-ply laminates[J]. Composites: Part A, 1999, 30 (4): 593- 597.