层合板分层失效数值模拟与参数识别

Numerical simulation and parameter identification of delamination failure for laminate

为了精确预测纤维增强复合材料层合板分层失效问题,提出基于虚拟裂纹闭合法的复合材料层合板分层失效准则参数的识别方法.通过双悬臂梁(DCB)试样和末端缺口弯曲(ENF)试样准静态力学试验获得I型和Ⅱ型分层断裂韧性.综合虚拟裂纹闭合法和有限元法,分别建立I型、Ⅱ型以及I/Ⅱ混合型分层数值仿真模型.基于已有的分层混合模式试验数据验证该方法的有效性.针对汽车用平纹机织碳纤维复合材料,利用纯I型和纯Ⅱ型试验和混合模式弯曲试样仿真模型,对分层失效准则参数进行了识别.结果表明,运用所建立的参数识别方法能够准确地得到层合板分层失效准则参数,有效克服了传统试验方法获取失效参数的成本高和周期长的问题.

The method of parameter identification for delamination failure criterion was proposed based onvirtual crack closure technique （VCCT） in order to predict accurately delamination failure of fiber-reinforced composite laminate. The delamination fracture toughness of mode I and mode Ⅱ was obtainedusing quasi-static mechanical tests of double cantilever beam （DCB） and end notch flexure （ENF）,respectively. The delamination FE models of mode I, mode 1I and I/11 mixed-mode were made usingVCCT and FEM. The proposed method was validated using existing mixed-mode experimental data. Theparameters of power criterion and Benzeggagh-Kenane （B-K） criterion were identified using mixed-modeexperimental data from reference. The delamination failure parameters was identified using experimentalresults of mode I and mode II and simulative result of mixed-mode bending （MMB）, for plain weave CFRPin automobile. Results show that parameters of failure criterion can be obtained accurately by the proposedmethod, which overcomes the high cost and long period of traditional experimental method.