Based on continuum damage mechanics (CDM), a multi-scale progressive damage model (PDM) is developed to analyze the uniaxial compression failure mechanisms of 2D triaxially braided composite (2DTBC). The multi-scale PDM starts from the micro-scale analysis which obtains the stiffness and strength properties of fiber tows by a representative unit cell (RUC) model. Meso-scale progressive damage analysis is conducted subsequently to predict the compression failure behaviors of the composite using the results of micro-scale analysis as inputs. To research the free-edge effect on the local failure mechanisms, meso-scale models of different widths are also established. The stress-strain curves obtained by numerical analysis are verified with the experimental data. Results show that fiber and matrix compression failure inside the fiber tows are the major failure modes of the composite under axial compression. For transverse compression, the dominated failure modes are recorded for matrix compression failure inside the fiber tows. It is also presented that the free-edge effect plays an important role in the transverse mechanical response of the composite, and the failure behaviors of the internal fiber tows are strongly influenced as well.

基于连续损伤力学（CDM），建立了多尺度渐进损伤模型（PDM）来分析二维三轴编织复合材料（2DTBC）的单轴压缩破坏机理。多尺度PDM从微观分析开始，该分析通过代表性的单位单元（RUC）模型获得纤维束的刚度和强度特性。随后进行中尺度渐进式损伤分析，以微观尺度分析的结果作为输入来预测复合材料的压缩破坏行为。为了研究自由边缘对局部破坏机制的影响，还建立了不同宽度的细观模型。实验数据验证了通过数值分析获得的应力-应变曲线。结果表明，纤维束内部的纤维和基体压缩破坏是复合材料在轴向压缩下的主要破坏方式。对于横向压缩，记录主导失效模式以用于纤维束内部的矩阵压缩失效。还提出自由边缘效应在复合材料的横向机械响应中起重要作用，并且内部纤维束的破坏行为也受到很大影响。