摘要
测量聚碳酸酯在3.8×10^(-5)s^(-1)到大约8000s^(-1)应变率范围内的单向压缩力学行为,研究了应变率对聚碳酸酯屈服应力的影响.结果表明:在应变率低于1s^(-1)时,聚碳酸酯先出现应变软化,然后出现稳定的塑性流动和应变硬化;在高应变率时,应力应变曲线的软化区域消失,屈服应力和屈服应变随着应变率的增大而增大.分析了高应变率时热软化与应变硬化的竞争机制,提出了描述宽应变率范围内聚碳酸酯的屈服应力与应变率关系的幂律型本构模型,能在较宽的应变率范围描述聚碳酸酯屈服应力与应变率的关系.
The uniaxial compression mechanical behavior of polycarbonate has been measured at strain rates ranging from 3.8×10^-5s^-1 to 8200 s^-1. The effect of strain rate on the yield stress of polycarbonate has been investigated at a wide range of strain rates. The results showed that at low strain rates, first an initial elastic response followed yielding, strain softening and then a dramatic strain hardening; at high strain rate, the softening dominating of stress strain curves disappeared and the yield stress and yield strain of polycarbonate increased with strain rates increasing. Competing mechanisms between strain softening and strain hardening of polycarbonate at high strain rates are discussed. Power law constitutive model for analysis of yield stress at a wide range of strain rates was proposed, which provides a better description relationship between yield stress and strain rates of polycarbonate from low to high strain rates.
出处
《材料研究学报》
EI
CAS
CSCD
北大核心
2007年第4期439-443,共5页
Chinese Journal of Materials Research
基金
中国工程物理研究院科学技术基金20040865资助项目.~~
关键词
有机高分子材料
聚碳酸酯
屈服应力
屈服应变
应变率
organic polymer materials, polycarbonate, yield stress, yield strain, strain rate
