摘要
为研究重组竹顺纹受压蠕变性能,对12个重组竹受压试件进行了蠕变试验,通过分析蠕变增长率和Burgers模型中各参数,得到重组竹受压试件受压蠕变变化规律。结果表明,重组竹在持续受压荷载作用下,应力水平较低时,蠕变变形发展稳定,不会发生承载力破坏;应力水平较大时(达到60%极限载荷水平),将会直接导致重组竹受压屈曲破坏,蠕变变形呈非稳定性增长;重组竹受压蠕变应变增长率随时间增加而逐渐增大,其增长速率则呈减速状态,受压蠕变的应变增长率随应力比增加而增大。基于试验结果,分析了重组竹受压蠕变试验的弹性变形、黏弹性变形和黏性变形的变化规律,对不同荷载水平的Burgers模型参数进行确定,并进一步推导了Burgers模型参数随应力水平的变化规律。基于此,建议考虑荷载水平的重组竹受压蠕变预测模型,模型预测结果与试验曲线一致。
In order to study the compressive creep performance of bamboo scrimber,creep tests were carried out on twelve bamboo scrimber specimens.By analyzing the creep growth rate and the parameters in Burgers model,the variation law of compression creep was obtained.The results show that the creep deformation of bamboo scrimber,subjected to compressive loads effect,develops stably and the bamboo scrimber is not destructed under the bearing capacity when the stress level is low.When the stress level is large(reaching 60%of the ultimate load),it will directly lead to the buckling failure of bamboo scrimber,and the creep deformation will show an unstable increase.The growth rate of the compressive creep strain of the bamboo scrimber gradually increases with the increase of time,its growth rate shows a decelerating state and the growth rate also increases as the stress ratio goes up.Based on the results,the variation law of elastic deformation,viscoelastic deformation and viscous deformation in the compression creep test were given.The parameters of Burgers model with different load levels were determined,and the variation law of parameters with stress level was derived.Based on above,a prediction model that takes into consideration the stress level for compressive creep of bamboo scrimber is proposed,and the results are consistent with the test curves.
作者
陈思
魏洋
赵鲲鹏
杭晨
赵康
CHEN Si;WEI Yang;ZHAO Kunpeng;HANG Chen;ZHAO Kang(College of Civil Engineering,Nanjing Forestry University,Nanjing 210037,China)
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2021年第3期944-952,共9页
Acta Materiae Compositae Sinica
基金
国家自然科学基金(51778300,51208262)
江苏省自然科学基金(BK20191390)
江苏省“六大人才高峰”资助项目(JZ-017)
江苏省重点研发计划(BE2020703)
江苏省“青蓝工程”资助项目(QL2020)。
