申请者在前期研究中发现，当OSB板（定向刨花板）与轻钢矩管桁架梁完全抗剪连接时，能明显地增加其弯曲刚度和极限承载力，并影响上弦管的局部稳定，但目前对轻钢矩管桁架梁组合楼盖的研究较少，且未定量地考虑OSB板的有利作用。本项目拟采用试验和理论分析方法研究轻钢矩管桁架梁-OSB板组合楼盖的力学性能。首先由试验确定自攻螺钉连接的抗剪刚度，并通过桁架梁及其OSB板组合楼盖的受弯性能试验验证有限元模型的正确性，接着利用有限元分析轻钢矩管桁架梁及其组合楼盖受力性能的影响因素；然后基于压弯构件理论分析上弦管的局部屈曲，验证有效宽度法对于上弦管强度及稳定性验算的适用性，并通过考虑交界面上的滑移效应分析轻钢矩管桁架-OSB板组合梁的抗弯刚度；最终提出桁架梁及其组合楼盖承载力的计算方法，以及组合梁抗弯刚度的简化计算公式。研究成果可为编制相关规范提供理论依据，对推动轻钢结构体系的发展应用具有重要的科学意义。

In the previous study, it was found that the flexural rigidities and ultimate capacities of Light Gauge Steel(LGS) square tube truss girders could be notably enhanced if full shear connection with Oriented Strand Board (OSB) was applied. Meanwhile, the stability of the upper cord girder could also be improved. Currently, limited research studies can be found about LGS-OSB composite floor, and no qualitative consideration about the positive effect of OSB is proposed. This project intends to investigate the bearing capacity and flexural rigidity of the LGS-OSB composite floor through experimental studies and theoretical analyses. First of all, the shear stiffness of the self-tapping screw will be determined by experimental test. And the accuracy of FEM models will be verified based on the experimental data. Then, Finite Element Method (FEM) will be used to analyze the influencing factors of the structural behavior of the LGS-OSB composite floor. Furthermore, the local buckling of the upper cord of the truss girder will be studied based on theoretical analyses of compression-flexural member, in order to verify the feasibility of applying the effective width method on calculating the strength and the stability of the upper cord of the truss girder of the composite floor. Also, the flexural rigidity of LGS-OSB composite floor will be studied considering the slide effect at the interface of OSB and truss girders. Finally, analytical methods to calculate the bearing capacity of the LGS truss girder and LGS-OSB composite floor and the flexural rigidity of the LGS-OSB composite girder will be proposed. This project can provide the theoretical basement for drafting the related structure design codes, and will be significant for promoting the development and application of LGS structure system.