基于仿真方法的CFRP复合材料孔隙率与超声衰减系数的关系  

Relationship between porosity and ultrasonic attenuation coefficient of CFRP based on simulation method

作　　者：丁珊珊[1] 金士杰[1] 何晓晨 罗忠兵[1] 林莉[1] 

机构地区：[1]大连理工大学无损检测研究所,大连116024

出　　处：《复合材料学报》2018年第1期89-94,共6页Acta Materiae Compositae Sinica

基　　金：国家重点基础研究发展计划(2014CB046505);国家自然科学基金(51275075)

摘　　要：为从超声衰减机制角度解释碳纤维增强树脂基(CFRP)复合材料孔隙率P与超声衰减系数α之间呈非唯一对应关系的原因,针对厚度为2mm的热压罐成型单向CFRP层板,建立了具有不同孔隙尺寸的CFRP模型(P=0.5%~3.5%),并采用数值计算方法得到衰减系数α值。当孔隙横向尺寸D=56μm,即归一化波数kD=2πD/λ<1(超声波波长λ≈560μm)时,α随P增大而缓慢线性增加;当D=93μm(kD≈1)时,α随P增大呈对数增长。仿真结果表明,超声波在含孔隙CFRP中传播时,随着归一化波数的不同,超声波衰减可能包括瑞利散射和随机散射两种机制,孔隙形貌的随机复杂性导致CFRP孔隙率与超声衰减系数之间呈现非唯一对应关系。A non-unique corresponding relationship was verified between porosity Pand ultrasonic attenuation coefficientαin carbon fibre reinforced polymer（CFRP）.In order to explain the relationship from the point of ultrasonic scattering mechanisms,the CFRP models containing various size of voids（P=0.5% ～3.5%）were established according to a kind of unidirectional CFRP laminate with thickness of 2 mm manufactured by autoclave moulding process.And the values of ultrasonic attenucation coefficientα were obtained by numerical calculation method.When the transverse dimension Dof void is 56μm and the normalized wavenumber kD=2πD/λ1（the wavelengthλ≈ 560μm）,αincreases linearly and slowly with the increasing of P.Andαshows logarithmic growth with the increasing of P when D=93μm（kD ≈1）.The simulation results show that,the ultrasonic attenuation may include two kinds of mechanism of Rayleigh scattering and Stochastic scattering depending on the normalized wavenumber when the ultrasound propagate in CFRP containing voids.The random and complex void morphology causes a nonunique corresponding relationship between porosity and ultrasonic attenuation coefficient.

关 键 词：碳纤维增强树脂 孔隙率 仿真 超声衰减 超声散射 

分 类 号：TB332[一般工业技术—材料科学与工程]