三维碳/碳复合材料板件拉伸强度预报

针对三维碳/碳复合材料板件开孔敏感性问题进行了试验与有限元分析。建立了三维碳/碳复合材料代表体积单元(RVE)和完好板件、开孔板件的有限元模型,给出了宏观应力到细观应力的转换方法,并基于此方法,实现了完好板件、开孔板件拉伸破坏过程的数值模拟。进行了三维碳/碳复合材料完好板件和开孔板件的单向拉伸试验,模拟计算结果与试验结果吻合良好。分析了不同宽径比(WTDR)对开孔板件拉伸强度的影响,其中当宽径比达到6时,开孔板拉伸极限强度相比完好板下降11.5%,可以认为如果宽径比不低于6,开孔对板件拉伸极限强度影响较小。该结论可以为碳/碳复合材料开孔板件设计提供指导。

Prediction on the tensile strength of 3D carbon/carbon composite plate

Experiments and finite element analysis were carried out for the problem of open hole sensitivity of 3D carbon/carbon composite material plates.Finite element models of the representative volume element (RVE),the intact plate and open-hole plates of 3D carbon/carbon composite were established.Transition method between macro level stress and meso level stress was given and numerical simulation on the tensile failure of the intact plate and open-hole plates was implemented based on this method.By uniaxial tensile tests of 3D carbon/carbon composite intact plates and open-hole plates,good agreement between numerical results and experiments was observed.In addition,the influence of width to diameter ratio (WTDR)on the tensile strength was analyzed.The results show that the tensile strength of open-hole plate decreases by 1 1.5% comparing with that of intact plate when the WTDR reaches 6 .It can be considered that the open hole makes little influence on the tensile strength of plates if the WTDR is not less than 6.And the result of the investigation provides insight into the design of carbon/carbon composite open-hole plate.