塑性变形类型与罗德系数的关系  

Relationship between Lode parameter and deformation type

作　　者：苑世剑[1] 李峰[1] 何祝斌[1] 

机构地区：[1]哈尔滨工业大学材料科学与工程学院,哈尔滨150001

出　　处：《哈尔滨工业大学学报》2008年第1期61-64,共4页Journal of Harbin Institute of Technology

基　　金：国家自然科学基金资助项目(50525516)

摘　　要：为深入研究各应变参量间的内在联系,推导出应变增量与罗德系数间关系的表达式,直观地给出了不同应变增量间的定量变化关系.对塑性变形类型与罗德系数间的关系进行了定量表征,揭示了塑性变形类型与应力状态的内在联系.对典型工艺的研究结果表明:随着高径比增加,圆环压缩过程中处于伸长类变形区域范围逐渐缩小;随着模角的增大,挤压过程中塑性区内应变类型由均一的伸长类变为3种共存,因此,材料流动的不均匀性也显著地增大.研究结果对塑性理论及其应用具有重要意义.In order to study inherent relation of strain parameters in depth, the relation between different strain increments and Lode parameter was formulated, hence the quantitative relation between strain increments was given directly. The deformation type and the Lode parameter were connected with each other directly. There- fore, the inherent relationship between the deformation type and stress status was discovered. The results indicate that the scope of elongation deformation zone narrows with the increasing of height-to-diameter ratio in annulus compression, the deformation types of the metal in the plastic deformation area change from a single type of elongation to three types of deformation, i. e. , elongation plane strain compression, with the increasing of die angle in extrusion. As a result, the homogeneity of metal flow decreased obviously. This research is of great Key significance to the plastic theory and its application.

关 键 词：罗德系数 塑性变形 应变增量 

分 类 号：O344.1[理学—固体力学]