考虑孔隙细观形貌随机性的复合材料孔隙率超声无损检测原理和方法

项目名称： 考虑孔隙细观形貌随机性的复合材料孔隙率超声无损检测原理和方法

项目编号： No.51275075

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 机械、仪表工业

项目作者： 林莉

作者单位： 大连理工大学

项目金额： 80万元

中文摘要： 复合材料孔隙细观随机形貌对超声波传播有显著影响。针对现有超声衰减法检测孔隙率研究中对孔隙形貌的假设过于简化，导致理论预测和实验结果存在明显偏差的问题，遵循"细观可辨、宏观可测、结果唯一、准确可靠"的原则，瞄准航空复合材料孔隙率无损检测的迫切工程需求开展研究。针对碳纤维增强复合材料，将随机介质理论和统计学方法相结合，建立三维随机孔隙模型。考查孔隙率与孔隙形貌之间的相关性，依据信息熵理论对孔隙随机形貌模拟结果的不确定性进行度量。将超声检测实验研究和数值模拟相结合，综合分析孔隙率、孔隙形貌对超声波传播特性的影响，阐明含孔隙复合材料超声衰减机理。基于声阻抗和衰减系数对孔隙率以及孔隙形貌特征敏感度的差异，提出准确可靠的复合材料孔隙率无损检测原理和方法。研究工作具有明显的原始创新性，不但能够推动建立航空复合材料孔隙率无损检测技术，同时能够为复合材料细观力学研究提供全新的思路借鉴。

中文关键词： 碳纤维增强复合材料；真实形貌孔隙模型；超声检测；孔隙率；孔隙形貌

英文摘要： The mesoscale morphology of random void in composite materials has significant influences on ultrasonic propagation. The void morphology was hypothesized over-simplifiedly in the existing ultrasonic technique of porosity using attenuation coefficient, and there is apparent deviations between various theoretical predictions and experimental results. Aiming to nondestructive prediction of porosity, which is demanded urgently for aeronautic composites,this project has been proposed. During our research, the principle of "mesoscale distinguishable, macroscale measurable, unique result, accurate and reliable" will be followed. For the carbon fiber reinforced composite materials, the random medium theory and statistical method are combinedly applied to establish the 3D random void model (RVM). The relation between porosity and void morphology will be discussed. According to the entropy theory, the quantitative evaluation principle and method of the uncertainty of simulation results for random void morphology will be proposed. Combining ultrasonic testing experiments and numerical calculations, influences of porosity and void morphology on ultrasonic propagation will be comprehensively analyzed, and ultrasonic attenuation mechanism of composites containing voids can be deeply understood and cleared. Based on the sensit

英文关键词： carbon fibre reinforced plastics；real morphology void model；ultrasonic testing；porosity；void morphology