碳布叠层/碳复合材料动态压缩性能测试研究

利用带有波形整形器的Split Hopkinson Pressure Bar(SHPB)技术测试了碳布叠层/碳复合材料在应变率为500、1 500 s-1时的动态压缩性能。研究结果表明:利用轧制紫铜作为整形器材料不仅可以有效地实现对碳布叠层/碳复合材料的常应变率压缩加载，而且有助于改善试样两端的应力平衡，从而保证测试数据的可靠性；此外，与准静态压缩相比较，在动态压缩载荷下，碳布叠层/碳复合材料的压缩强度有较强的应变率效应，且复合材料压缩强度的动态增加函数可以用Cowper-Symonds幂函数的形式来表示。

Experimental investigation on dynamic compressive behaviors of carbon cloth/carbon composites

Dynamic compressive behaviors of carbon cloth /carbon composites were experimentally studied at the strain rates of 500,1 500 s-1 by the split Hopkinson pressure bar with pulse shaper.Experimental results show that the pulse shaping technique ensures nearly constant strain-rate deformation experienced by specimens under dynamically equilibrated stresses so that accurate stress-strain curves at two high rates can be obtained.Compared with quasi-static compression,the dynamic compressive strength of carbon cloth/carbon composite has strong stain-rate sensitivity and it increases with strain rate.A phenomenological strain-rate-dependent material model of Cowper-Symonds power function was proposed to describe the stress-strain response of composites.The calculated results by the proposed model agree well with the experimental data at high and low strain rates.