落叶松胶合木柱轴心受压性能研究

RESEARCH ON THE MECHANICAL PROPERTIES OF LARCH GLULAM COLUMN UNDER AXIAL COMPRESSION

目前国内对速生材落叶松胶合木柱的研究主要局限于短柱,为了研究中长柱和长柱的轴压力学性能,对5组不同长细比的落叶松胶合木柱进行试验研究,分析其竖向应变、横向应变、侧向位移、极限承载力等随长细比的变化规律,探讨长柱的破坏形态和破坏机理。试验结果表明:随着长细比的增加,胶合木长柱的极限承载力逐渐降低,并且逐渐由强度破坏转变为失稳破坏。在落叶松胶合木短柱试验结果的基础上,通过回归分析得到了长柱极限承载力折减系数经验算式,并与GB 50005—2003《木结构设计规范》进行对比,为国产速生材落叶松胶合木柱的设计和推广应用提供借鉴。

At present, researches on the fast-growing larch glulam columns are mainly restricted to the stub column in China. In order to study the mechanical properties of middle long columns and long columns under axial loading, experimental study on five sets of larch glulam columns with different slenderness ratios was carried out. Variations of experiment data with slenderness ratio changing such as vertical strain, lateral strain, lateral deflection, ultimate bearing capacity etc were comparatively analyzed, the failure pattern and mechanism of long columns were discussed. The results indicated that the ultimate bearing capacity of long larch glulam columns gradually decreased with slenderness radio increasing, and the failure mode was gradually converted from strength failure to instability failure. The empirical formula of the ultimate load reduction factor was obtained by regression analysis based on the experimental results of short columns of larch glulam. Comparative analysis was also carried out between the fitted curve based on the experimental results and the ultimate load reduction factor obtained from the formula in the code for design of timber structures of China. The research results could provide a basis for the design and application of the domestic fast-growing larch glulam columns.