复合材料裂纹敏感性的评定──（Ⅱ）HTA／6376和T300／M10的Ⅱ型分层扩展行为

ASSESSMENT OF CRACK SENSITIVITY IN COMPOSITES──(Ⅱ)MODE II DELAMINATION GROWTH BEHAVIOR OF HTA /6376 AND T300/M10

应用ＥＮＦ试验研究了ＨＴＡ／６３７６和Ｔ３００／Ｍ１０两种碳／环氧复合材料的静态与疲劳层间断裂行为。在静态载荷下，两种材料均呈现脆性不稳定和稳定的裂纹扩展特性。在Ｒ＝０．１且△Ｇ＿Ｉ大幅度变化的疲劳加载过程中，两种材料呈现稳定的裂纹扩展。采用位移控制方法，确定了裂纹扩展速率与循环应变能释放率的关系和应变能释放率门槛值。与Ｔ３００／９１４Ｃ相比，ＨＴＡ／６３７６和Ｔ３００／Ｍ１０具有较高的抗裂纹扩展能力。

The end notched flexure(ENF)test was employed in an investigation ofinterlaminar fracture behavior in Mode II static and fatigue loading for carbon/epoxycomposites T300/M10 and HTA/6376.Under static loading,both of the materialsexhibited bittle unstable and brittle stable behavior of crack growth.Stable Mode II crackgrowth was. observed during fatigue loading with R=0.1 in a larger range of cyclic strainenergy release rate.A consistent relation of crack growth rate to the cyclic strain energyrelease rate was obtained for the composites. Within the range of moderate crack growthrate,the data of Mode II fatigue crack growth obeyed a power law. The trend of reductionin crack growth rate data with degredation in cyclic strain energy release rate suggests thepresence of a threshold strain energy release rate,Compared with T300/914C,HTA/6376and T300/M 10 have higher crack growth resistance.