超导粉末BSCCO单晶体本构行为  

Constitutive behavior of a superconducting powder BSCCO crystal

作　　者：赵迎红[1] 雷丽萍[1] 曾攀[1] 

机构地区：[1]清华大学机械工程系先进成形制造教育部重点实验室,北京100084

出　　处：《清华大学学报（自然科学版）》2006年第11期1813-1815,1819,共4页Journal of Tsinghua University(Science and Technology)

基　　金：国家自然科学基金资助项目(50305015);国家杰出青年科学基金资助项目(59825117)

摘　　要：超导粉末B i2S r2C an-1CunO2n+1(BSCCO)的高致密度和强c-轴织构是形成B i-2223/A g高温超导带材较高临界电流密度的关键,传统的塑性理论很难模拟与预测晶体材料BSCCO的各向异性力学行为以及变形过程中的织构演化。采用率相关的晶体塑性理论,针对BSCCO低对称晶体结构的特点,通过在主方向上加运动约束,建立其弹塑性本构模型及数值积分过程,并利用ABAQU S/UM AT子程序进行二次开发,完整构建了基于晶体塑性理论的有限元数值分析平台。利用该平台,分析了双滑移系启动的典型变形模式。模拟结果表明,拉伸变形有助于BSCCO晶体内微裂纹的形成和扩展,而压缩变形则会抑制微裂纹的形成和扩展。The high density and the sharp c-axial texture of the superconducting powder Bi2Sr2Can-1CunO2n＋1（BSCCO） are the key factors for achieving high critical current densities in Bi-2223/Ag tape. The classical plasticity theory does not accurately simulate the anisotropy and texture evolution of the polycrystalline BSCCO. This study is based on a rate-dependent crystal plasticity model where each single crystal is kinematically constrained in the principal directions of the orthorhombic unit cell according to the low symmetry of BSCCO. An elastic plastic constitutive model was developed and input into an ABAQUS/UMAT subroutine for crystalline BSCCO. The numerical model was used to study the typical deformation mode where two slip systems are active at the beginning of deformation. The results indicate that tension induces the formation and development of micro-cracks in the BSCCO crystal while compression suppresses them.

关 键 词：晶体塑性 BSCCO 织构演化 各向异性 本构模型 

分 类 号：O344[理学—固体力学]