中文摘要：

稳定问题是C型檩条在风吸力作用下的主要控制因素,该文基于薄壁杆件结构力学以及经典梁理论,提出了可以精确计算简支C型檩条在风吸力作用下的应力计算方法,该方法可以同时考虑压型钢板对檩条上翼缘侧向及扭转约束支撑的影响。依据相关试验资料以及数值计算结果,验证了该方法的精度。然后,基于该文所提出的方法,针对檩条横截面应力分布、侧向位移等力学性能,以及有无拉条等构造措施对其极限状态的影响进行了参数分析。研究表明,压型钢板对檩条上翼缘的侧移及扭转约束及拉条措施会改变檩条横截面应力分布及侧向位移,对其稳定极限状态产生显著影响。

英文摘要：

The stability problem is a key concern for the performance of C-section purlins under wind loading. Aiming at this problem, a semi-analytical model is proposed for predicting the longitudinal stresses of simply supported C-section purlins considering both lateral and rotational restraints by sheeting. Formulae used to calculate the longitudinal stresses of the roof purlins are derived by using the classical bending theory of the thin-walled beams. To validate the accuracy of the present model, a comparison is made between the analytical results data obtained from software Maple and the test data from related literatures. It is shown that the results calculated from the proposed model agree well with the data from these two methods. Thereafter, the parameter analyses on the stress and displacement are conducted, and the effects of lateral and rotational stiffness on the limit states are investigated. The results also shows that the bracing restraint can change the buckling mode of purlins. The model proposed can be used to calculate the longitudinal stresses distribution and displacement of simply supported purlins under uplift loadings.