摘要
利用可动边界的变分理论与方法,求得了裂纹扩展时能量泛函的二阶变分,由二阶变分为零的条件求得裂纹扩展的临界状态和临界速度,并根据临界速度推演出裂纹扩展的寿命计算公式。寿命计算公式适用于固体系统的各种状态。(如弹性体,非线性弹性体,塑性状态,蠕变状态),具有重要的理论意义与实用价值。
|Based on the theory and method for variational problems of variable boundary, the second variation of the energy functional for crack extension is obtained. If the second variation vanishes. the critical condition and the critical velocity for crack extension are got. Then the formula of life prediction can be applied to various conditions of solid system, such as elasticity, nonlinear elasticity, elasto-plasticity and creep condition, which is of great importance theoretically adn of great value practically.
出处
《北京工业大学学报》
CAS
CSCD
1991年第2期26-30,共5页
Journal of Beijing University of Technology
关键词
裂纹
扩展
寿命
变分法
临界条件
crack extension, variational problem of variable boundary, coiticak condition
