毛竹受压构件性能试验研究

Experimental investigation on bamboo columns under axial compression

为研究双肢抱合竹杆件的受压性能,对6个单根圆竹杆件和9个用钢横隔板连接、绑扎连接两种方式构成的双肢抱合竹杆件进行了试验研究和计算方法对比。分析了单个圆竹杆件和双肢抱合竹杆件的承载力、破坏模式,单个圆竹杆件与双肢抱合竹杆件的承载力关系,连接方式对双肢抱合竹杆件承载力的影响。试验结果表明:圆竹具有良好的受压承载性能,受压过程中弯曲变形较大,卸载后回弹性好,是一种良好的建筑材料;单根圆竹杆件和双肢抱合杆件受压弯曲变形后,最终发生整体弯曲失稳破坏;不同连接方式对双肢抱合杆件的承载力影响较小,双肢抱合竹杆件的承载力约是单个圆竹杆件承载力的2倍;与直接捆绑连接相比,采用钢横隔板连接装置后,2个分肢竹杆件变形趋于一致,构件整体性更好,可用于结构受力较大部位。试验结果与现有的4种竹受压杆件算法的结果对比表明,有3种算法的结果与试验结果吻合较好,有1种算法的略大于试验结果。

In order to study the compression performance of the built-up raw bamboo columns, the experimental research and calculation methods were compared for the six single raw bamboo columns and nine built-up bamboo columns which composited by the two ways: steel transverse diaphragm plate and bundling connection. The ultimate compressive capacities and failure modes of specimens, the relationship of ultimate compressive capacities between single raw bamboo columns and built-up bamboo columns, and the influence of connecting devices on ultimate compressive capacities of built-up bamboo columns were obtained and analyzed from tests. The investigation results indicate that the raw bamboo members have good compressive capacities, the performance of flexural deformation is excellent under compressive load, the elastic resilience of raw bamboo members is good.Thus the raw bamboo is a good building material. When a single raw bamboo column and a built-up bamboo column are compressed and deformed, the collapse mode is eventually controlled by the global flexure buckling. The ultimate bearing capacities of built-up bamboo columns are almost two times of those of single raw bamboo columns. The different ways of connecting have a slight influence on ultimate compressive capacities of built-up bamboo columns. Compared with the bundling connection, after the steel transverse diaphragm plate connection device is used, the deformation of the two limb bamboo members tends to be uniform, and the component is better in integrity, which can be used to afford to more compression. Four different approaches are applied to calculate the ultimate compressive capacities of bamboo columns. Three of the four calculation approaches are in good agreement with the experiment results, and only one is slightly greater than the experimental values.