Experimental investigation into the mechanical properties of scrimber composite for structural applications
Experimental investigation into the mechanical properties of scrimber composite for structural applications
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DOI：
10.1016/j.conbuildmat.2020.122234
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发表时间：
2021-03
影响因子：
7.4
通讯作者：
Xiaofeng Sun;Minjuan He;F. Liang;Zheng Li;Liji Wu;Yongliang Sun
中科院分区：
文献类型：
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作者：
Xiaofeng Sun;Minjuan He;F. Liang;Zheng Li;Liji Wu;Yongliang Sun
重组木复合材料是一种新型的工程木基建筑材料，它是利用小径树种重组结构木材而制成的。通过对速生白杨重组木复合材料的清晰试件进行力学性能试验，并对一组实尺重组木梁进行抗弯性能试验，获得结构尺度重组木受弯构件的抗弯性能。然后，将该重组木复合材料与其他常见的工程木和竹重组木进行力学性能的比较。最后，根据重组木复合材料顺纹拉伸和顺纹压缩应力应变关系的实验结果，提出了简化的纵向应力应变模型。结果表明，重组木复合材料具有理想的力学性能，其力学性能与其它常用的工程木/竹制品相当甚至上级。在顺纹或顺纹压缩条件下，重组材的破坏模式主要为韧性破坏，如压缩区的压碎破坏和劈裂破坏，断裂沿着纹扩展;然而，对于重组木复合材料在剪切、拉伸和弯曲情况下，其特征在于脆性破坏模式，例如具有平坦断裂的拉伸破坏和沿粘结表面的沿着剪切破坏。此外，还证明了采用重组木的透明试件的设计强度进行结构尺度重组木受弯构件的设计是合理和保守的。重组木顺纹压缩应力应变关系的非线性特征可用一个四次多项式函数描述。
Scrimber composite is a novel engineered wood-based construction material that is manufactured by reconstituting structural lumber using small-diameter tree species. In this study, clear specimens of the scrimber composite made from fast-growing poplar trees were tested to comprehend their mechanical properties; besides, a group of full-scale scrimber beams was tested to acquire the bending properties of structural-scale scrimber bending members. Then, comparison of mechanical properties was conducted among this scrimber composite, other common engineered wood, and bamboo scrimber. Finally, simplified longitudinal stress–strain models were proposed based on the experimental stress–strain relationships of the scrimber composite under the parallel-to-grain tension and parallel-to-grain compression scenarios. Results show that the scrimber composite can provide ideal mechanical properties, which are comparable or even superior to those of other common engineered wood/bamboo products. For the scrimber under the parallel-to-grain or perpendicular-to-grain compression, it is featured by ductile failure modes, such as crushing failure at the compressive zone and splitting failure with fractures propagating along the grain; whereas, for the scrimber composite under the shear, tension, and bending scenarios, it is featured by brittle failure modes, such as tension failure with flat fractures and shear failure along the bonding surface. Besides, it is proven that using the design strength of the clear specimens of the scrimber is reasonable and conservative for the design of structural-scale scrimber bending members. For the scrimber under the parallel-to-grain compression, the nonlinear characteristics of its stress–strain relationship can be described by one fourth-order polynomial function.