重组竹在长期荷载作用下的蠕变行为

Creep Behavior of Bamboo Scrimber under Long-Term Load

通过长期荷载作用下的拉伸与压缩蠕变试验,研究了重组竹在不同应力水平下的蠕变行为特点及变化规律.分别釆用Burgers模型和Findley幂律模型对重组竹在长期荷载作用下的蠕变曲线进行拟合,确定了重组竹蠕变模型,分析了Burgers模型和Findley幂律模型的相关系数及变化规律.结果表明:在不同应力水平下,重组竹蠕变应变-时间曲线均呈现出相似的变化趋势,均包含瞬态蠕变和稳态蠕变阶段;采用Burgers模型和Findley幂律模型都能很好地模拟重组竹的蠕变性能;瞬间弹性形变、延迟弹性形变和黏性流动形变均随应力水平的增加而增大.高应力水平下的蠕变可导致重组竹构件破坏,在设计时应合理地控制应力水平.

The creep behavior of the bamboo scrimber under different stress levels was analyzed by the tensile and compressive creep test of the bamboo scrimber specimen under long-term load.The Burgers model and the Findley s power law model were used to fit creep testing curve of the bamboo scrimber under long-term load,and the bamboo scrimber creep model was established.The correlation coefficient and the variation law of the Burgers model were analyzed.The results show that bamboo scrimber creep strain-time curves generally have a similar tendency under different stress level,which includes the temporary creep and stationary creep stage.Burgers model and Findley s power law model fit creep behavior of bamboo scrimber well.The instantaneous elastic and viscous deformation and delayed elastic deformation increases with the increasing of stress level.The creep deformation can lead to component damage under high stress level.Therefore,the stress level should be reasonably controlled in the design.