低速冲击后压缩强度是复合材料层合板的重要性能指标.在分析CCF300/5428复合材料层合板遭受不同能量等级低速冲击后压缩强度试验数据的基础上,提出一种基于广义回归神经网络技术的低速冲击后压缩强度估算模型.该模型以冲击能量、凹痕深度以及损伤面积为输入参数，以高斯函数为隐含层激励函数，使用部分试验数据训练，寻找最优光滑因子.此外，以最优光滑因子对所提模型进行重构并采用部分试验数据对该模型进行验证.结果表明：基于广义回归神经网络的模型具有较好的试验数据泛化能力，可用于估算低速冲击后复合材料的压缩强度.
The compressive strength after low-velocity impact is a key performance index of the composite laminates. By analyzing data of compressive strength experiment of CCF300/5428 composite laminates after low-velocity impact (LVI) under different energy levels, a prediction model based on generalized regression neural network technology of compressive strength after LVI is proposed. This model uses the impact energy, the dent depth and the damage area as input parameters and the Gauss function as the hidden layer excitation function. The model uses part of the experimental data to train for finding the optimal smoothness coefficient. Then, the model is reconstructed with the optimal smoothness coefficient, and is simulated with part of the experimental data. Results show that the model has good generalization ability of experimental data and is feasible to estimate the compressive strength after low-velocity impact.
［1］DANG T D, HALLETT S R. A numerical study on impact and compression after impact behaviour of va-riable angle tow laminates［J］. Composite Structures, 2013, 96(4): 194-206.
［2］SUEMASU H. Analytical approaches to compression after impact (CAI) behavior of carbon fiber-reinforced composite materials［J］. Advanced Composite Materials, 2014, 25(1): 1-18.
［3］SUEMASU H, ICHIKI M. Analytical study on low compressive strength of composite laminates with impact damage［J］. Composite Structures, 2013, 104(5): 169-175.
［4］SLATTERY P G, MCCARTHY C T, HIGGINS R M O. Assessment of residual strength of repaired so-lid laminate composite materials through mechanical testing［J］. Composite Structures, 2016, 147: 122-130.
［5］JEFFERSON A J, ARUMUGAM V, SARAVANAKUMAR K, et al. Compression after impact strength of repaired GFRP composite laminates under repeated impact loading［J］. Composite Structures, 2015, 133: 911-920.
［6］KULKARNI M D, GOEL R, NAIK N K. Effect of back pressure on impact and compression-after-impact characteristics of composites［J］. Composite Structures, 2011, 93(2): 944-951.
［7］NASH N H, YOUNG T M, STANLEY W F. An investigation of the damage tolerance of carbon/benzoxazine composites with a thermoplastic tough-ening interlayer［J］. Composite Structures, 2016, 147: 25-32.
［8］HABIB F A. A new method for evaluating the resi-dual compression strength of composites after impact［J］. Composite Structures, 2001, 53(3): 309-316.
［9］BORRELLI R, FRANCHITTI S, CAPRIO F D, et al. A repair criterion for impacted composite structures based on the prediction of the residual compressive strength［J］. Procedia Engineering, 2014, 88: 117-124.
［10］沈真, 杨胜春, 陈普会. 复合材料抗冲击性能和结构压缩设计许用值［J］. 航空学报, 2007, 28(3): 561-566.
SHEN Zhen, YANG Shengchun, CHEN Puhui. Behaviors of composite materials to withstand impact and structural compressive design allowableness［J］. Acta Aeronautica et Astronautica Sinica, 2007, 28(3): 561-566.
［11］REMACHA M, SNCHEZ-SEZ S, LPEZ-ROMANO B, et al. A new device for determining the compression after impact strength in thin laminates［J］. Composite Structures, 2015, 127: 99-107.
［12］ZHANG A Y, LU H B, ZHANG D X. Effects of voids on residual tensile strength after impact of hygrothermal conditioned CFRP laminates［J］. Composite Structures, 2013, 95: 322-327.
［13］RIVALLANT S, BOUVET C, ABI ABDALLAH E A, et al. Experimental analysis of CFRP laminates subjected to compression after impact: The role of impact-induced cracks in failure［J］. Composite Structures, 2014, 111: 147-157.
［14］TAN W, FALZON B G, CHIU L N S, et al. Predicting low velocity impact damage and compression-after-impact (CAI) behaviour of composite laminates［J］. Composites Part A: Applied Science and Manufacturing, 2015, 71: 212-226.
［15］MAIO L, MONACO E, RICCI F, et al. Simulation of low velocity impact on composite laminates with progressive failure analysis［J］. Composite Structures, 2013, 103: 75-85.
［16］贾建东, 丁运亮, 胡伯仁. 复合材料层合板低速冲击后压缩破坏的数值模拟［J］. 机械科学与技术, 2010, 29(10): 1320-1324.
JIA Jiandong, DING Yunliang, HU Boren. Numerical simulation of the compressive failure of composite laminates under low velocity impact［J］. Mechanical Science and Technology for Aerospace Engineering, 2010, 29(10): 1320-1324.
［17］ROMANO F, DI CAPRIO F D, MERCURIO U. Compression after impact analysis of composite panels and equivalent hole method［J］. Procedia Engineering, 2016, 167: 182-189.
［18］SPECHT D F. A general regression neural network［J］. IEEE Transactions on Neural Networks, 1991, 2(6): 568-576.
