数字图像相关方法辅助的IM7/8552碳纤维/环氧树脂复合材料单向带层合板沿厚度方向非线性本构参数识别

提出了采用数字图像相关(DIC)方法和有限元模型修正(FEMU)技术相结合,通过短梁剪切(SBS)试验获得碳纤维增强环氧树脂(IM7/8552)正交各向异性复合材料单向带层合板沿厚度方向压缩本构关系参数的试验方法.该方法根据假设材料初始本构,采用3D有限元模型(FEM)计算获得主平面压头下方沿厚度方向的应力和应变分布,...

Digital image correlation aided method for identification of nonlinear constitutive parameters of IM7/8552 carbon fiber/epoxy composite unidirectional laminate along thickness directionction

A digital image correlation(DIC)aided method combined with finite element model updating(FEMU)technique was proposed to identify the compressive constitutive parameters along the thickness direction for carbon fiber/epoxy(IM7/8552)orthotropic composite unidirectional laminate through short beam shear(SBS)test.The stress and strain distributions on the loading plane along the thickness direction under the loading nose were calculated by 3D finite element model(FEM)with the initial trial parameters.A cost function of the square difference between DIC-measured and FEM-calculated strains was given accordingly and unknown constitutive parameters were determined iteratively through minimization of it.The stress distribution is weakly sensitive to the constitutive parameters since the SBS test configuration is nearly statically determinate.Thus minimization of the cost function can be achieved by the least squared linear regression between FEM-calculated stress and DIC-measured strain.The advantages of the proposed method include that an explicit sensitivity matrix is not required in the iterative procedure,the efficiency of the parameter identification is high,and it is not sensitive to the initial trial parameters.