Structural Performance of Prefabricated Timber-Concrete Composite Floor Constructed Using Open Web Truss Joist Made of LVL Paraserianthes Falctaria

This paper investigates an open web truss joist (OWTJ) made of laminated veneer lumber (LVL) Paraserianthes falctaria as a prefabricated timber-concrete composite floor system. The four-point bending test showed that structural performances of the OWTJ, conventional composite floor (CCF), and prefabricated composite floor (PCF) were similar. Although composite action was not developed as no lateral deformation was observed at the shear connectors, installing a concrete slab above the OWTJ can slightly increase the ductility factor of the composite floor. Furthermore, a finite element model was developed, and the model proved to be suitable for simulating the structural performance of the composite floor.

腹板开洞竹木工字梁受力性能的试验研究

以洞口尺寸、形状和净距为参数,对28根开孔梁和2根实腹梁的力学性能进行了试验研究与对比分析,研究其破坏形态及破坏机理等,并与未开孔梁的试验结果进行对比.提出了基于费氏空腹桁架理论的开孔梁承载力计算公式.结果表明,开孔梁内的应力分布、挠度变化不再完全符合传统弯曲理论.随着径腹比的加大,开孔梁的承载力和刚度呈显著下降趋势.方孔梁的承载力略大于外接圆孔,以外接圆孔代替方孔梁的承载力偏于安全.对于径腹比为0.5的多洞口梁而言,当方洞和圆洞净距分别大于2倍和2.5倍孔长时,可忽略洞口间的相互影响.通过对比分析,理论结果与实验结果的误差平均值为15%左右,从而验证了修正后的空腹桁架理论计算公式的准确性和可靠性.