大应变下金属材料拉伸、压缩时横向变形系数变化规律及实验方法的探讨

The Experimental Method of Determining Poisson's Ratio and its Variation in Tension and Compression for Metals under Large Deformation

本文对九种常用金属材料,在常温、静载、大应变范围进行拉伸、压缩试验,经反复卸载加载,测得了P—△1及△d—△1曲线。研究了横向变形系数μp 的变化规律.观察了卸载—加载时E及μ(?)的变化规律.对有显著屈服平台的塑性材料,屈服阶段△d-△1曲线不规则变化的原因,做了探索性的实验。并提出了初步见解.

For nine commonly used metals the tensional and compressive tests withlarge plastic deformation were carried out at room temperature.By severalstatic unloading-loading circulations the P-△1 and △d-△1 curves wereobtained.The variation of poisson's ratio μ_p was investigated,and themodulus E and Poisson's ratio μ_e were determined during the unloading-load-ing process.For materials with significent yield plateau,the irregularitiesof △d-△1 curves in the yield region were observed and the mechanism of thephenomenon was primarily explained.