铝合金板厚度对硼纤维/环氧复合材料单面修复效果的影响

Effects of aluminum alloy plate thickness on single-sided repair efficiency for boron fiber/epoxy composites

  • 摘要: 采用单向硼纤维/环氧复合材料补片真空袋压工艺单面修复不同厚度含中心裂纹铝合金板,测试了修复试件的热学及准静态力学性能,并采用三维有限元模型分析了修复试件的残余热应变和应力强度因子。结果表明:修复试件的弯曲挠度随铝合金板厚度增大而减小;修复试件铝合金板下表面裂纹尖端附近的残余热应变随铝合金板厚度增大而增大,补片上表面的残余热应变则随铝合金板厚度增大而减小,这与有限元分析结果吻合较好。含中心裂纹铝合金板的应力强度因子随铝合金板厚度增大而减小,而单面修复试件的应力强度因子随铝合金板厚度增大而增大。采用相同长度和宽度的单向硼纤维/环氧复合材料补片单面修复后,铝合金板厚度为1. 76 mm修复试件的承载能力保留率为 93. 85 %,而厚度为 10. 20 mm修复试件的只有 84. 01 %;修复试件的刚度得到了完全恢复,等效刚度均大于完好试件的刚度。

     

    Abstract: Taking vacuum pack techniques for patches of boron fiber/epoxy (Bf/epoxy) composites,this study tested thermal properties and quasi-static mechanics properties of the single-sided repaired aluminum alloy plate of different thickness with a cent ral crack in it . It analyzed the residual thermal strain and stress intensity factor (SIF) of the repair specimen by using a 3D finite element model,The results show that the bending deflection of the repair specimen decreases with the increase of the plate thickness. The residual thermal strain at the crack tip of the lower plate surface increases with the increase of the plate thickness,and the residual thermal strain of the upper patch surface increases with the decrease of plate thickness , which conformed well to the finite element analysis results.SIF of the aluminum alloy plate with central crack decreases with the increase of plate thickness,while the SIF of the single-sided repair specimen increases with the increase of plate thickness. Af ter the patches of unidirectional Bf/epoxy composites of the same length and width was repaired , the retention rate of bearing capacity for the repair specimen of 1. 76mm thick plate is 93. 85 % while for the plate of 10. 20 mm it is only 84. 01 %. The stiffness of the repair specimen is reactivated and the equivalent stiffness is larger than that of the no-flaw specimen.

     

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