纯铜后继屈服面的测试与晶体塑性模型模拟

发布时间：2018-03-04 10:03

本文选题：纯铜　切入点：后继屈服　出处：《力学学报》2017年04期 　论文类型：期刊论文

【摘要】：通过纯铜薄壁圆管试样的实测和晶体塑性模拟,用单试样法和多试样法对分别经历拉伸、扭转和组合拉扭变形的试样后继屈服面进行研究.考虑预变形方式、测点数目、测试顺序和指定平移应变等不同条件,对后继屈服面测定结果差异及屈服面内凹现象进行探讨.在此基础上,比较了单试样和多试样两种方法的合理性与有效性.数值模拟采用能反映Bauschinger效应的晶体塑性模型,试样有限元模型每个单元的晶体取向均随机生成,能反映多晶材料变形特征.模拟试验加载过程与真实试验一致.研究表明:(1)采用本文方法可再现真实试验过程,模拟后继屈服面测试展示的现象与实测相近,证实了方法的有效性和合理性;(2)模拟测试与实测均发现,薄壁圆管组合拉扭加载测得的后继屈服面可能出现内凹,单试样法测得屈服面的内凹现象尤为显著;(3)若试验材料的材质比较一致,用多试样法测试后继屈服比用单试样法更合理.
[Abstract]:Based on the measurement and crystal plastic simulation of pure copper thin-walled tube specimens, the subsequent yield surfaces of specimens subjected to tensile, torsional and combined tensile and torsional deformation were studied by single specimen method and multi-specimen method respectively. The number of measuring points was taken into account in the pre-deformation mode. In this paper, the difference of the measurement results and the concave phenomenon of the yield surface are discussed under different conditions, such as the test sequence and the specified translation strain. The rationality and validity of the single and multi-sample methods are compared. A crystal plastic model reflecting the Bauschinger effect is used in the numerical simulation. The finite element model of the sample is generated randomly for each element. It can reflect the deformation characteristics of polycrystalline material. The loading process of simulated test is consistent with that of real test. The research shows that the real test process can be reproduced by using the method in this paper, and the phenomenon of simulating subsequent yield surface test is similar to that of real test. The validity and reasonableness of the method are verified. (2) it is found that the subsequent yield surface measured by combined tension and torsional loading of thin-walled circular pipes may have an internal concave. The concave phenomenon of yield surface measured by single specimen method is especially obvious. If the material material is consistent, it is more reasonable to test subsequent yield with multi-sample method than with single sample method.
【作者单位】：广西大学土木建筑工程学院工程防灾与结构安全教育部重点实验室/广西防灾减灾与结构安全重点实验室;
【基金】：国家自然科学基金(11472085,11272094,11632007) 广西科技厅项目(桂科合1599005-2-5) 广西区优秀博士学位论文培育项目(YCBZ2015008)资助
【分类号】：O344.1

【相似文献】