藏青杨旧材无疵试样力学性质试验研究

Experimental study on mechanical properties of small clear specimens of aged Tibetan populus cathayana

藏青杨是藏式古建筑木结构的常用材料,但目前对该种材料的力学性质研究不足,尤其是藏式古建筑中的藏青杨旧材。为此,通过对锯解自一根典型藏式古建木结构旧梁的无疵试样进行力学测试,得到了藏青杨旧材的力学性质参数。研究表明:高宽比为1∶3试样的径向、弦向局部抗压强度较全截面抗压强度分别提升33.8%和64.2%;对于文中使用的小尺寸受拉试样,试样的锯解方式对抗拉性质影响较大;在考虑强重比的情况下,对于大多数藏式木结构构件,落叶松是更为合适的替换用材,而若仅需要对横纹径向受压构件进行替换时,红松则更合适。此外,通过试验得到的藏青杨旧材弹性常数也可作为藏式古建筑木结构仿真建模和有限元分析的基础。

Tibetan populus cathayana is a commonly used material for wooden structures of Tibetan ancient buildings,but existing research has little understanding on the mechanical properties of this material,especially the aged Tibetan populus cathayana in ancient Tibetan buildings.Through mechanical tests of the small clear specimens sawn from an aged Tibetan wooden beam,the mechanical parameters were obtained.The results show that the radial and transverse local compressive strengths with an aspect ratio of 1∶3 were 33.8%and 64.2%higher than the full-section compressive strengths,respectively.The sawing method has a great influence on the tensile properties.It is also found that considering the strength-to-weight ratio of replacement materials,for most Tibetan wood structural members,larix gmelinii is more suitable.And if only the transverse compression member needs to be replaced,pinus koraiensis is more suitable.In addition,the complete elastic constants of the aged Tibetan populus cathayana obtained from the experiment can also be used for simulation modeling and finite element analysis of Tibetan ancient wooden buildings.