新型自攻螺丝修复带纵缝木梁抗弯性能

Flexural behavior of cracked beams retrofitted by self-tapping screws

本文针对带纵缝木梁抗弯承载力和自攻螺丝修复效果开展了试验和理论分析。基于35根木梁和相应材性试验获得了开裂和自攻螺丝修复后开裂木梁的承载力系数,并基于梁理论,推导建立了考虑纵缝长度和截面高度位置以及自攻螺丝贯入角和间距等因素的承载力修复系数计算方法。试验结果表明,理论公式与试验结果的误差≤21%,具有较高的预测精度,可以用于指导工程实践。

Longitudinal cracks in wood beams of historical timber structures are commonly seen and can impair the load-carrying capacity of such beams. This paper presents the flexural loading test results of 35 full -scale wood beams, with saw kerfs simulating lengthwise checks, to identify the influence of cracks and the retrofitting effect of self-tapping screws. Analytical solutions were derived for the moment resistance of the cracked wood beams and those retrofitted by self-tapping screws, with consideration of the length and vertical position of the cracks and the inclination and spacing of the screws. Comparison between the predictive results and the test results showed the errors were less than 21%, indicating good agreement. The generated knowledge can be used as reference for retrofitting designs of existing timber members.