钢板增强胶合木梁的抗弯性能

Bending performance of glued-lumber beam reinforced with steel plate

为了改善普通胶合木梁的受力性能,提出了在其底部粘贴钢板或增设螺钉的增强方式,从而形成钢板增强胶合木梁。进行了21根梁的抗弯试验,分析了钢板厚度、是否设置螺钉对梁破坏形态、承载力和变形能力的影响,并与普通胶合木梁进行对比。结果表明:粘贴2、3和4mm厚钢板增强后,梁承载力分别提高了73.3%、90.0%和71.0%,随着钢板厚度的增加,承载力先增大后减小;粘贴同厚度钢板并设置螺钉后,梁承载力分别提高了76.4%、96.9%和148.6%,随着钢板厚度的增加,承载力增大,螺钉的增强效果在钢板较厚时表现明显。钢板增强后,梁的极限变形比普通胶合木梁提高了6.2%~61.1%,钢板厚度和是否设置螺钉对梁变形能力的影响与其对承载力的影响类似。在验证了钢板增强胶合木梁基本符合平截面假定后,提出了此类构件的受弯承载力计算公式,并与试验结果进行对比,结果表明,理论值与试验值的平均误差不大于10%。

To improve the mechanical property of common glued-lumber beam, an reinforcing method is proposed, that steel plate is fixed on the bottom of beam by pasting or screwing. Bending test of 21 beams were conducted to analyze the influences of steel plate thickness, with or without the screwing on beam failure mode, bearing capacity and deformation capacity in comparison with common clued-lumber beam. The bearing capacities are respectively increased by 73.3%, 90.0% and 71.0% by pasting steel plates with thickness of 2 mm, 3 mm and 4 mm, indicating that as the thickness of the steel plate increases the bearing capacity increases first then decreases. When both pasting and screwing are used with the above values of thickness, the bearing capacities are increased by 76.4%, 96.9% and 148.6% respectively, indicating that bearing capacity increases with the thickness of the steel plate, and the reinforcing effect of thicker steel plate is obvious. With steel plate reinforcement, the ultimate deformation is increased by 6.2% to 61.1% than that of common glued-lumber beam, and the influences of the steel plate thickness and screwing are similar to that of bearing capacity. After verification of the glued-lumber beam reinforced with steel plate conformed on the plain section, the bending capacity calculation formula of similar constructional member is proposed. The average error between the theoretical value and testing value is less than 10%.