包壳管三维力学建模及其变形分析软件开发

燃料棒包壳通常为锆合金制成的圆筒状结构，在堆内复杂的“高温-高压-辐照”作用下因结构蠕变导致坍塌，从而失去其结构功能危害反应堆运行安全。本文基于连续介质力学理论，建立三维包壳结构的控制方程，并开发有限元数值计算软件BINE3D。本软件计算结果与商业有限元软件ABAQUS结果一致。随着辐照时间的增加，包壳管蠕变变形逐渐增加、蠕变变形速率逐渐降低，最终可能导致包壳坍塌。包壳管的初始椭圆度越大，辐照变形的总椭圆度越大。本软件可为包壳的结构设计、安全分析和寿命评估提供指导。

Three-dimensional Mechanical Modeling of the Cladding and its Deformation Analysis Software Development

The cladding of the fuel rod is a cylinder-shaped structure made of Zirconium alloy, which will collapse due to structural creep under the extremely service conditions such as high-temperature, high-pressure and high-irradiation. The collapse of the cladding results in losing its structure function and threatening the safety of the reactor. Based on the continuum mechanics theory, the governing equations of three-dimensional cladding structure are established and the finite element numerical calculation software BINE3D is developed. The creep deformation of the cladding increases and the creep deformation rate decreases gradually as the increasing of the irradiation in the reactor, which may lead to the collapse of the cladding eventually. The results of the software are consistent with the commercial finite element software ABAQUS. The software can be utilized to structural design, safety analysis and life evaluation of the fuel rod cladding.