摘要
本文认为只有当应力超过长期强度σ_L时,才会产生塑性流动,从而把总应变率分解为衰减蠕变和非衰减蠕变应变率两部分,并建立了一个适用于静荷或重复加载的能够反映温度效应的粘弹塑本构模型。该模型中的材料常数和待定函数可由不同温度、不同荷载下的常应力压缩蠕变实验曲线拐点(破坏点)对应的应变率ε_m和时间t_m以及外应力小于或等于长期强度的蠕变实验资料确定,其确定方法具有明显的物理意义,而且结果是唯一的。利用该方法确定了冻结粉砂的材料参数,把其代入本文的本构模型,其计算结果与实验结果符合较好。
It is considered that plastic flow occurs only when stress exceeds long-term strength of frozen soil. Total strain rate may be decomposed into two parts: damping and nondamping creep strain rates. A viscoelastoplastic constitutive model including the effect of temperature is suggested which is suitable for both static and repeated loading conditions. Parameters and indefinite functions in the model can be determinated with
the minimum strain rate (εm) and the time to failure (tm) corresponding to the inflection point on creep curves under-various constant stresses and temperatures and the creep test data in which creep stress is equal to or less than long-term strength. The method of determination of the parameters has a clear physical meaning. Calculated results based on the constitutive model show a good agreement with test results.
出处
《冰川冻土》
CSCD
北大核心
1990年第1期31-40,共10页
Journal of Glaciology and Geocryology
关键词
冻土
粘弹塑性
本构模型
材料参数
frozen soil, viscoelastoplastic, constitutive model, material parameters
