【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。更多还原

【Abstract】 The high density and the sharp c-axial texture of the superconducting powder Bi₂Sr₂Ca_n-1Cu_nO_2n+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.更多还原