材料期刊网

TEMPERING RESPONSE OF A DEFORMED LOW CARBON DUAL PHASE STRUCTURE

JIN Man , JIANG Zhonghao , NAN Shenghui , HU Jiandong , LIAN jianshe(Jilin University of Technology , Changchun , China)(Manuscript received 8 February 1995)Correspondent:LI Geping , (Institute of Metal Research , Chinese Academy of Sciences , Shenyang 110015 , China)

金属学报(英文版)

The low carbon dual phase structure was cold de formed first,then was tempered at 200 to 600℃.The variation in strength and ductility during tempering of the steel was investigated.It was found that a fter the de formed dual phase structure was tempered at 200 to 600℃, with the increase in the tempering temperature the tensile strength decreases rapidly;the lotal elongation remains constant at 200 to 500℃ but began to rise dramatically at a critical temperature between 500 and 600℃.However,when the non-deformed dual phase structure was tempered at the same temperature range,the tensile strength decreases and the total elongation increases continuously with the increase of temperature.It was demonstrated from TEM analysis that precipitating carbides density along the boundaries ofmartensite lath and the recrystallized grains are responsible for the tempering response ofthe de formed dual phase structure.

关键词: :de formed dual phase structure , null , null

RELATIONSHIP BETWEEN TENSILE DEFORMATION BEHAVIOUR AND MICROSTRUCTURAL PARAMETERS OF A DUAL PHASE STEEL

JIANG Zhonghao , GUAN Zhenzhong , ZHANG ZuomeiChangchun Institute of Optics and Fine Mechanics , Chinese Academy of Sciences , Changchun , ChinaLIA N JiansheJilin University of Technology , Changchun , China

金属学报(英文版)

Bused on the deformation model of dual phase steels, an expression for the stress of martensite in dual phase steels is derived, it predictes that the onset of plastic deformation of martensite (transition strain) depends on the strain hardening of ferrite and on the strength of martensile. The relationship between the flow stress and microstructural parameters of a 0.12C-0.9Mn dual phase steel was investigated using the expression for the flow stress of dual phase steel[1] . By calculating the stress ratio and the stress-strain partition coefficient, the loud transition and the stress-strain partition between two phases are studied. It shows that the deformation of dual phase steel lies between the isostress and isostrain states and the stress-strain pratition changes continuously during the deloramtion.

关键词: dual phase steel , null , null , null

Ion sputter erosion in metallic glass-A response to "Comment on: Homogeneity of Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass" by L-Y. Chen, Y-W. Zeng, Q-P. Cao, B-J. Park, Y-M. Chen, K. Hono, U. Vainio, Z-L. Zhang, U. Kaiser, X-D. Wang, and J-Z Jiang J. Mater. Res. 24, 3116 (2009)

Journal of Materials Research

The morphology of the dark and bright regions observed by transmission electron microscopy for the Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass strongly depends on the ion beam parameters used for ion milling. This indicates that the ion beam could introduce surface fluctuation to metallic glasses during ion milling.

关键词: room-temperature

基于粒子群和有限元的材料本构模型参数的确定

倪永中 , 徐鸿

材料科学与工程学报

本文提出了一种基于粒子群算法和有限元方法的弹塑性本构方程参数的确定方法,并在此基础上开发了参数自动优化系统CMPI(Constitutive Material Parameter Identification).通过使最小二乘形式的目标函数达到极小值,实现参数的动态寻优;模型参数作为粒子群优化模块的输入,采用应变(应力)控制方法,调用材料非线性有限元模块计算特定参数时的应力(应变)响应,并计算与实验数据的误差,从而实现优化过程.CMPI目前适用于A-F类模型(Chaboehe、Ohno-Wang、Jiang-Sehitoglu)的参数优化,以此为基础,不难扩展到其他材料模型.

关键词: 粒子群 , 材料非线性 , 有限元 , Ohno-Wang 模型

混杂CFRP/GFRP筋HPC梁的非线性梁壳组合单元研究

张剑 , 周储伟 , 雷笑 , 叶见曙 , 卓家寿

复合材料学报

对于混杂CFRP/GFRP筋高性能混凝土(HPC)梁,研究一种新的三维非线性梁壳组合单元,对HPC梁进行了全过程分析.引入实体退化壳单元理论,利用空间梁单元模拟预应力CFRP筋,并根据CFRP筋单元节点线位移和转角位移的协调性,推导CFRP筋单元对梁壳组合单元刚度矩阵的贡献,同时对GFRP筋和HPC梁采用分层壳单元模拟.并运用Jiang屈服准则、Madrid强化准则等描述混凝土的材料非线性,提出一种新的非线性梁壳组合单元,研制相应的三维非线性计算程序.计算结果与试验数据吻合良好,说明本文构造的非线性梁壳组合单元的正确性和研制程序的可靠性,以及混凝土材料非线性描述的合理性;采用组合单元能准确模拟CFRP筋的几何构形,能综合考虑其拉压弯剪性能,利于全面地反映配筋对结构的增强作用.

关键词: CFRP筋 , GFRP筋 , 梁壳组合单元 , HPC梁 , 材料非线性