【摘要】 鉴于高模量碳纤维复合材料压缩强度实测值和理论计算值的较大误差,为了更好地分析高模量复合材料的压缩性能,针对纤维含量为69%的国产高模量M40J环氧单向板的纵向受轴压破坏的试件,用台式扫描电镜拍摄了单向板受压断裂时断裂面的照片,通过观察分析可知单向板在受压时由于纤维屈曲失稳产生了破坏。随后建立了单向板细观力学有限元模型,分析得到了单向板的弹性模量,并将强度极限试验值与经典的以纤维的小波长微失稳为假设的伸长型压缩强度和剪切型压缩强度等理论值做了对比,最后得到了与实测结果比较吻合的细观力学模型。相比较于单向复合材料经典压缩强度理论,采用这种圆柱组合体单向板有限元模型分析得出的高模量复合材料压缩性能更接近试验实测值,对于高模量复合材料的设计和应用有一定的参考价值。更多还原

【Abstract】 In view of the large error of the measured values of the compressive strength of the high modulus carbon fiber composite material and the theoretical calculation value,in order to better analyze the compression performance of the high modulus composite material,the domestic high modulus M40 J epoxy one-way with a fiber content of 69% is unidirectional.The longitudinal fracture of the plate was subjected to the axial compression failure.The photo of the fracture surface of the unidirectional plate under pressure fracture was photographed by a desktop scanning electron microscope.It was found by observation and analysis that the unidirectional plate was damaged due to the buckling instability of the fiber under pressure.Subsequently,a meso-mechanical finite element model of a circular fiber distributed in a resin in a hexagonal shape was established.The elastic modulus of the unidirectional plate was obtained,and the strength limit test value and the classical small wavelength of the fiber were obtained.The micro-stability is compared with the theoretical values such as the assumed elongational compressive strength and the shear-type compressive strength.Finally,the micromechanical model which is consistent with the measured results is obtained.Compared with the classical compressive strength theory of unidirectional composites,the compression performance of high modulus composites obtained by finite element model analysis of cylindrical composite unidirectional plates is closer to the experimental values,and the design of high modulus composites has certain reference value.更多还原