紫铜的循环棘轮行为研究

Ratchetting Behavior of Pure Copper under Uniaxial Cyclic Stresses

对紫铜进行了单轴应变控制和应力控制下的系统循环试验。揭示了紫铜在应变循环下的循环应变幅值历史、平均应变对循环特性的影响；分析了该材料在应力循环下的应力幅值、平均应力及其历史对循环蠕变（棘轮应变）的影响，得到了紫铜单轴循环行为的一些有意义的结果。发现无论单轴应变循环特性还是棘轮效应不但依赖于当前加载状态。

An experimental investigation was carried out on cyclic properties of pure copper subjected to uniaxial cyclic trains and stresses. The effects of cyclic strain amplitude history and mean strain on the cyclic deformation behavior of pure copper were investigated. The influences of stress amplitude, mean stress and their histories on the cyclic creep, i.e., ratchetting, were analysed. Some significant results were obtained. It is shown that either uniaxial cyclic property under cyclic strains or ratchetting under asymmetric uniaxial cyclic stresses depends not only on the current loading state, but also on the previous loading history.