重组竹在长期荷载作用下的蠕变行为
|
摘要
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.
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.
引文
[1] 张晓敏,孙正军,王喜明.竹材径向压缩蠕变行为研究[J].林业机械与木工设备,2010,38(6):26-27.ZHANG Xiaomin,SUN Zhengjun,WANG Ximing.Study on radical compression creep behavior of bamboo wood[J].Forestry Machinery and Wood Working Equipment,2010,38(6):26-27.(in Chinese )
[2] 闫薇,崔海星,朱一辛.竹材的拉伸短期蠕变行为及模拟[J].林业科技开发,2013,27(3):46-47.YAN Wei,CUI Haixing,ZHU Yixin.Analysis and simulation of moso bamboo short-term tensile creep behavior[J].Forestry Science and Technology Development,2013,27(3):46-47.(in Chinese )
[3] 徐咏兰,华毓坤.不同结构杨木单板层积材的蠕变和抗弯性能[J].木材工业,2002,16(6):10-12.XU Yonglan,HUA Yukun.Creep behavior and bending properties of poplar LVL in different assembly types[J].China Wood Industry,2002,16(6):10-12.(in Chinese )
[4] SMITH I,LANDIS E,GONG M.Fracture and fatigue in wood[M].England:John Wiley & Sons Ltd.,2003:53-58.
[5] 周华樟.旋切板胶合木的蠕变及其对结构稳定性的影响[D].哈尔滨:哈尔滨工业大学,2009.ZHOU Huazhang.Creep of LVL and its effect on the stability of structures[D].Harbin:Harbin Institute of Technology,2009.(in Chinese)
[6] 徐滨雁.浅谈木质材料的普通蠕变性[J].林业科技情报,2003,35(3):72-73.XU Binyan.A brief talk on the common creep of woodiness material[J].Forestry Science and Technology Information,2003,35(3):72-73.(in Chinese)
[7] 金维洙,贾娜.单板层积梁弯曲蠕变特性[J].东北林业大学学报,2007,35(10):30-32.JIN Weizhu,JIA Na.The bending creep properties of LVL[J].Journal of Northeast Forestry University,2007,35(10):30-32.(in Chinese)
[8] BULLEIT W M,SANDBERG L B,WOODS G J.Steel reinforced glued-laminated timber[J].Journal of Structural Engineering,1989,115(2):433-434.
[9] MATTHEW D,MASSIMO F.Long-term behavior of pre-stressed LVL members(Part I):Experimental tests[J].Journal of Structural Engineering,2011,137(12):1553-1561.
[10] 曹岩,徐海龙,王伟宏,等.模压成型的杨木纤维/高密度聚乙烯复合材料蠕变性能和蠕变模型[J].复合材料学报,2016,33(6):1174-1178.CAO Yan,XU Hailong,WANG Weihong,et al.Creep properties and creep model of poplar wood fiber/high-density polyethylene composites prepared by compression molding[J].Acta Materiae Compositae Sinica,2016,33(6):1174-1178.(in Chinese )
[11] CUI H X,GUAN M J,ZHU Y X,et al.The flexural characteristics of prestressed bamboo slivers reinforced parallel strand lumber(PSL)[J].Key Engineering Materials,2012,517:96-100.
[12] 李磊.现代新型竹材料蠕变性能及组合结构蠕变研究[D].长沙:湖南大学,2012.LI Lei.Research on creep property of glumbam and modern composite structure[D].Changsha:Hunan University,2012.(in Chinese)
[13] 吴培增.重组竹蠕变性能试验与分析[D].哈尔滨:东北林业大学,2015.WU Peizeng.Experiment and analysis on creep properties of reconsolidated bamboo[D].Harbin:Northeast Forestry University,2015.(in Chinese)
[14] 刘鹏飞,赵启林,王景全.树脂基复合材料蠕变性能研究进展[J].玻璃钢/复合材料,2013(3):109-117.LIU Penfei,ZHAO Qilin,WANG Jingquan.Progress in research on the creep behavior of resin composites[J].Glass Fiber Reinforced Plastic/Composite Materials,2013(3):109-117.(in Chinese)
[2] 闫薇,崔海星,朱一辛.竹材的拉伸短期蠕变行为及模拟[J].林业科技开发,2013,27(3):46-47.YAN Wei,CUI Haixing,ZHU Yixin.Analysis and simulation of moso bamboo short-term tensile creep behavior[J].Forestry Science and Technology Development,2013,27(3):46-47.(in Chinese )
[3] 徐咏兰,华毓坤.不同结构杨木单板层积材的蠕变和抗弯性能[J].木材工业,2002,16(6):10-12.XU Yonglan,HUA Yukun.Creep behavior and bending properties of poplar LVL in different assembly types[J].China Wood Industry,2002,16(6):10-12.(in Chinese )
[4] SMITH I,LANDIS E,GONG M.Fracture and fatigue in wood[M].England:John Wiley & Sons Ltd.,2003:53-58.
[5] 周华樟.旋切板胶合木的蠕变及其对结构稳定性的影响[D].哈尔滨:哈尔滨工业大学,2009.ZHOU Huazhang.Creep of LVL and its effect on the stability of structures[D].Harbin:Harbin Institute of Technology,2009.(in Chinese)
[6] 徐滨雁.浅谈木质材料的普通蠕变性[J].林业科技情报,2003,35(3):72-73.XU Binyan.A brief talk on the common creep of woodiness material[J].Forestry Science and Technology Information,2003,35(3):72-73.(in Chinese)
[7] 金维洙,贾娜.单板层积梁弯曲蠕变特性[J].东北林业大学学报,2007,35(10):30-32.JIN Weizhu,JIA Na.The bending creep properties of LVL[J].Journal of Northeast Forestry University,2007,35(10):30-32.(in Chinese)
[8] BULLEIT W M,SANDBERG L B,WOODS G J.Steel reinforced glued-laminated timber[J].Journal of Structural Engineering,1989,115(2):433-434.
[9] MATTHEW D,MASSIMO F.Long-term behavior of pre-stressed LVL members(Part I):Experimental tests[J].Journal of Structural Engineering,2011,137(12):1553-1561.
[10] 曹岩,徐海龙,王伟宏,等.模压成型的杨木纤维/高密度聚乙烯复合材料蠕变性能和蠕变模型[J].复合材料学报,2016,33(6):1174-1178.CAO Yan,XU Hailong,WANG Weihong,et al.Creep properties and creep model of poplar wood fiber/high-density polyethylene composites prepared by compression molding[J].Acta Materiae Compositae Sinica,2016,33(6):1174-1178.(in Chinese )
[11] CUI H X,GUAN M J,ZHU Y X,et al.The flexural characteristics of prestressed bamboo slivers reinforced parallel strand lumber(PSL)[J].Key Engineering Materials,2012,517:96-100.
[12] 李磊.现代新型竹材料蠕变性能及组合结构蠕变研究[D].长沙:湖南大学,2012.LI Lei.Research on creep property of glumbam and modern composite structure[D].Changsha:Hunan University,2012.(in Chinese)
[13] 吴培增.重组竹蠕变性能试验与分析[D].哈尔滨:东北林业大学,2015.WU Peizeng.Experiment and analysis on creep properties of reconsolidated bamboo[D].Harbin:Northeast Forestry University,2015.(in Chinese)
[14] 刘鹏飞,赵启林,王景全.树脂基复合材料蠕变性能研究进展[J].玻璃钢/复合材料,2013(3):109-117.LIU Penfei,ZHAO Qilin,WANG Jingquan.Progress in research on the creep behavior of resin composites[J].Glass Fiber Reinforced Plastic/Composite Materials,2013(3):109-117.(in Chinese)