结构用胶合竹力学性能试验研究

Experimental research on mechanical properties of glubam

格鲁斑胶合竹是一种天然竹纤维增强复合材料,为研究其受拉、受压、受弯及受剪等基本力学性能,综合参考《木材物理力学性能试验方法》、《木材无疵小试样的试验方法》等,进行了格鲁斑胶合竹材力学性能试验,得到了格鲁斑胶合竹抗压强度、弹性模量、抗弯强度、抗剪强度值,通过分析获得了较高拟合优度的抗拉强度和弹性模量与荷载-主纤维角度变化关系的指数拟合曲线。试验结果同时指出冷压胶合面对格鲁斑胶合竹材抗压强度有较强的削弱作用。最后,在对胶合竹结构设计方法讨论的基础上,给出了以中国木材容许应力设计方法为基础的格鲁斑胶合竹的容许设计应力建议值,并与其他几种胶合木材料进行了对比,表明格鲁斑胶合竹材能够满足建筑结构对材料主要力学性能的要求。

Glubam is a type of natural bamboo-fiber reinforced polymer composites.This paper focuses on the fundamental mechanical properties of glubam,including its modulus,tensile,compressive,flexural and shear strengths.Because glubam is a new structural material,there is no code or guideline to follow.By referring to relevant timber codes,including GB 1927~1943—1991 'Wood physical and mechanical properties test method' and ASTM D143-94(2007) 'Standard test methods for small clear specimens of timber',considerable number of tests were conducted to obtain the values of modulus,tensile,compressive,bending and shear strengths.The relationships between tensile strength,and modulus and the main fiber orientation were studied.The tests also reveal that cold glued joints between glubam surfaces can weaken the compressive strength.Through the discussion on design methods of glubam structure,the recommended allowable stress values were given based on the Chinese allowable stress design method of timber and favorable design results were found compared with other types of glue laminated timber.