2D-C/SiC复合材料的偏轴压缩力学行为  

THE OFF-AXIS COMPRESSIVE MECHANICAL BEHAVIOR OF 2D-C/SiC COMPOSITES

作　　者：宋远翔 杨成鹏[1] 李俊 贾斐 Song Yuanxiang;Yang Chengpeng;Li Jun;Jia Fei(School of Mechanics,Civil Engineering and Architecture,Northwestern Polytechnical University,Xi'an 710072,China;AVIC China Helicopter Research and Development Institute,Jingdezhen 333001,Jiangxi,China;School of Mechano-Electronic Engineering,Xidian University,Xi′an 710071,China)

机构地区：[1]西北工业大学力学与土木建筑学院,西安710072 [2]航空工业中国直升机设计研究所,江西景德镇333001 [3]西安电子科技大学机电工程学院,西安710071

出　　处：《力学学报》2025年第3期644-657,共14页Chinese Journal of Theoretical and Applied Mechanics

基　　金：国家自然科学基金(12072274,12472142);陕西省自然科学基金(2024JC-YBMS-308)资助项目.

摘　　要：陶瓷基复合材料的面内本构关系对于热结构的设计与评价具有重要参考意义.对2D-C/SiC复合材料的轴向压缩、面内剪切和偏轴压缩力学行为进行了实验和模拟研究.通过单调压缩和循环加卸载实验,研究了不同加载角度(0°,15°,30°和45°)下材料的应力应变行为以及卸载模量与残余应变随卸载应力的演变规律;并表征了面内剪切应变响应行为以及剪切卸载模量和残余应变随卸载应力的演化行为.在理论层面,考虑材料的正交各向异性、非线性和细观损伤机理,应用连续介质损伤力学方法对材料的压缩、剪切和压-剪耦合损伤演化行为进行了描述,且提出了面内剪切和偏轴压缩力学行为表征模型;并基于损伤演化实验数据确定了损伤解耦模型中的压-剪损伤耦合系数和损伤钝化系数,对材料的偏轴压缩应力应变行为进行了模拟.结果表明:该材料的轴向压缩本构关系为线弹性;而面内剪切本构关系为非线性,且卸载模量随卸载应力的增大而减小,残余应变随卸载应力的增大而增大;偏轴压缩载荷下,轴向压缩应力对材料的剪切损伤具有抑制作用,而面内剪切应力对材料的轴向压缩损伤起到了促进作用,且材料的应力-应变响应行为呈现出了相当的复杂性.但模拟结果与实验数据的一致性表明,基于损伤解耦的本构模型可以较为准确地预测材料的偏轴压缩应力-应变行为.The in-plane constitutive relationship of ceramic matrix composites holds significant reference value for the design and assessment of thermal structures.Experimentally and theoretically,the mechanical behaviors of 2D-C/SiC composites under axial compression,in-plane shear,and off-axis compression were investigated.Through monotonic compression and cyclic loading-unloading experiments,the stress-strain behaviors of 2D-C/SiC composites were studied,as well as the evolution of the unloading modulus and residual strain with respect to the unloading stress at different loading angles(0°,15°,30°,and 45°).Additionally,the in-plane shear strain response behavior and the evolution of the shear unloading modulus and residual strain with unloading stress were characterized.Theoretically,taking into account the orthogonal anisotropy,nonlinearity and microscopic damage mechanism of the material,the compression,shear and compression-shear coupling damage evolution behaviors of the material were described by applying the microscale mechanics and damage mechanics methods,and the characterization models for the in-plane shear and off-axis compression mechanical behavior were proposed.The compression-shear damage coupling coefficients and damage deactivation coefficients in the damage decoupling model were determined based on the damage evolution experimental data.The stress-strain behavior of the material under off-axis compression was simulated.The results reveal that the axial compression constitutive relationship of 2D-C/SiC composites is linear elasticity;in contrast,the in-plane shear constitutive relationship is nonlinear.Specifically,the unloading modulus decreases as the unloading stress increases,and the residual strain increases with the increase in unloading stress.Under off-axis compressive loading,the axial compressive stress inhibits the axial compressive damage of the material,while the in-plane shear stress plays a promotion,and the stress-strain response behavior of the material responses considerable comple

关 键 词：陶瓷基复合材料 正交各向异性 本构模型 损伤耦合 偏轴压缩 

分 类 号：O34[理学—固体力学] TB332[理学—力学]