基于应变不变量失效理论的碳纤维增强树脂基复合材料层合板开孔结构压缩损伤模拟

Compressive damage simulation of carbon fiber reinforced polymer matrix composite laminate open-hole structures based on strain invariant failure theory

应变不变量失效理论(SIFT)是一种新型的基于物理失效模式的复合材料强度理论,被广泛应用于复合材料结构失效分析。首先,为了提高理论分析的精度,SIFT被扩展用于分析碳纤维增强树脂基复合材料(CFRP)层合板开孔结构的静载压缩逐步失效机制和强度。开发的SIFT实施方法包括材料强度表征和结构强度预测两个部分。结构强度预测是基于ABAQUS平台并使用Fortran语言编写用户自定义材料子程序(UMAT)实现的。随后,将SIFT预测值与经典复合材料强度理论Tsai-Wu和Hashin理论的预测结果和试验结果进行了对比,结果显示SIFT预测的精度最高。同时,基于SIFT对静载压缩下的AS4/3501-6层合板开孔结构从初始失效到最终失效的失效机制演变进行了详细的分析。最后,将SIFT预测的AS4/3501-6层合板开孔结构静载压缩的失效机制与试验结果进行了对比。结果表明SIFT预测的逐步失效机制与试验结果相吻合,所得结论为CFRP结构强度的预测提供了新思路。

Strain invariant failure theory（SIFT）is a new type of strength theory for composites based on physical failure mode,which is applied to the failure analysis of composite structures widely.In order to improve the accuracy of theoretical analysis,SIFT was extended to be used to analyze the static loading compressive progressive failure mechanism and strength for carbon fiber reinforced polymer（CFRP）composite laminate open-hole structures firstly.The implementation methods of developed SIFT include two parts of material strength characterization and structure strength prediction.The structure strength prediction based on the ABAQUS platform and was realized by using the user defined material subroutine（UMAT）wrote by Fortran scripts.Then,the predicted values of SIFT as well as the predicted results of classical composites strength theories such as Tsai-Wu and Hashin theories were compared with the testing results,and the results showed that the accuracy of SIFT prediction was the best.Meanwhile,based on SIFT,the failure mechanisms evolution from initial failure to final failure of AS4/3501-6laminate open-hole structures under static loading compression were analyzed in details.Finally,the static loading compressive failure mechanisms of AS4/3501-6laminate open-hole structures predicted by SIFT were compared with testing results.The results show that the progressive failure mechanisms predicted by SIFT agree well with the testing results.The obtained conclusions provide new thoughts for the strength prediction of CFRP structures.