摘要
到目前为止,很少有人较深入地研究盐岩流变加速阶段的特性。利用微机控制三轴流变试验机,对盐岩试样进行三轴分级加载流变-损伤破坏试验。将第一作者提出的一维流变-损伤模型进行三维扩展,采用对时间的差分计算流变变形与损伤变量及变形,对试验数据进行拟合分析,较深入地研究了盐岩的流变损伤-破坏特性,得到了全程流变-损伤曲线,获得了过渡蠕变、稳态流变和加速流变各阶段的盐岩变形与损伤发展规律。模型对盐岩的加速流变-损伤阶段特性的描述与实验数据吻合较好,揭示了盐岩流变-损伤破坏特性。研究表明,分级加载条件下,盐岩的过渡蠕变不容忽视;盐岩的流变-损伤随时间增长与荷载水平加大而发展,由稳态流变-损伤到加速流变-损伤并没有十分明显的界限;损伤严重时,损伤引起的变形将在总变形中起决定性作用;一旦损伤变量超过损伤增速界限,宏观上流变/损伤达到加速阶段。
The characteristics of salt rock in the tertiary creep phase have been rarely investigated.Based on the results of triaxial multi-staged loading destructive creep-damage tests on salt rock samples,the creep-damage-rupture characteristics of salt rock are studied by means of the creep-damage model proposed by the author,complete creep-damage curves are obtained,and the laws of deformation and damage development of salt rock in the transitional,stationary and accelerating phases are deduced.The model proves well consistent with the test data,even in the accelerating creep-damage phase;it accounts for the creep-damage-rupture characteristics of salt rock.Under the condition of multi-staged loading,the primary creep deformation cannot be neglected.The creep and damage of salt rock occur with load increasing and time,as a result,the clear boundary between the stationary and the accelerating stage cannot be found.The deformation induced by damage will play a crucial role in the total deformation when the material is heavily damaged,e.g.damage factor is greater than the damage accelerating limit,and creep / damage reaches,in macroscopic view,accelerating phase.
出处
《工程力学》
EI
CSCD
北大核心
2013年第4期288-293,共6页
Engineering Mechanics
基金
国家自然科学基金项目(50874034)
天津市应用基础研究计划项目(07JCYBJC04100)
河北省自然科学基金项目(E2010000081)
关键词
盐岩
流变-损伤
破坏
特性
实验研究
salt rock
creep-damage
rupture
characteristics
experimental investigation
