室内自然变湿环境中木质工字梁的静曲蠕变  

Static Bending Creep of Wood I-Beam in an Indoor Natural Moisture Changing Environment

作　　者：董春雷[1,2] 张宏健[2] 

机构地区：[1]东北林业大学材料科学与工程学院,黑龙江哈尔滨150040 [2]西南林业大学材料工程学院,云南昆明650224

出　　处：《建筑材料学报》2014年第2期266-269,共4页Journal of Building Materials

基　　金：国家自然科学基金资助项目(31170534);西南林业大学校基金资助项目(111140)

摘　　要：对昆明1～3月室内自然环境下木质工字梁（IB）静曲蠕变进行试验、分析发现：室内自然变湿环境中的IB表现出环境湿度变湿阶段中蠕变挠度变小和环境湿度变干阶段中蠕变挠度变大的“阶段性吸着蠕变”行为，其昼夜自然变湿环境中的吸着蠕变行为则异于吸着蠕变的基本规律；IB的室内自然变湿蠕变总体行为与木质材料的普通静曲蠕变行为相似．以意杨PF—LVL为翼缘、竹定向刨花板为腹板的IB90d的自然变湿蠕变总挠度为5．33mm，其中，初始段的蠕变挠度和卸载后14d的不可恢复蠕变挠度分别为1．38，1．79mm，分别为蠕变总量的25．9％，33．6％．It was found that there was a periodic mechano-sorptive creep（MSC） behavior of the wood I- beam（IB） in an indoor natural moisture changing environment. Results from the experiment and analysis to approach the static bending creep of the IB in January to March in Kunming indicated that the deforma- tion decreased in the wetting period but increased in the drying period. However, its daily MSC behavior was quite different from the basic law of the MSC. Furthermore, the whole creep behavior of the IB in the indoor natural moisture changing environment was similar to a normal creep of solid wood. The total de- flection of the IB, which was flanged with PF-LVL of poplar and webbed with bamboo OSB, in 90 d was 5.33 ram, in which, the deflection in the first-stage creep and the irreversible deflection unloaded after 14 d were 1.38,1.79 mm, which occupied 25.9%,33.6% of the total deflection respectively.

关 键 词：木质工字梁 静曲蠕变 吸着蠕变 阶段性吸着蠕变 

分 类 号：TU366.3[建筑科学—结构工程]