轴心受压木构件稳定系数的统一算法

Unified method for calculation of stability coefficient of wood members in axial compression

GB 50005—2003《木结构设计规范》中轴心受压木构件稳定系数的计算方法和计算公式仅适用于方木或原木制作的构件,不适用于层板胶合木、进口锯材等经应力分级的现代木产品制作的构件。鉴于此,对各国木结构设计规范中稳定系数的计算方法进行比较分析,在继承我国传统计算方法和特点的基础上,结合现代木产品的特点提出新的适用于各类木产品构件的稳定系数统一算式。通过回归分析确定稳定系数算式中所含各系数对应不同木产品的值,使稳定系数的计算偏差基本控制在10%以内。对云杉-松-冷杉(SPF)规格材轴心受压构件进行稳定荷载试验研究和构件的随机有限元分析,所得稳定系数的随机有限元分析结果与试验结果、回归分析结果吻合良好,验证了所建议的稳定系数计算式的正确性和适用性。所提出的受压木构件的稳定系数统一算式保持了我国设计计算方法的延续性,并能满足木结构设计的需要。

The method and equations for calculation of the stability coefficient of wood members in axial compression in the current Chinese code for design of timber structures only apply to members made of sawn or round timber,yet can not apply to members made of modern wood products such as imported sawn lumber and glued laminated timber,which are stress-graded. The methods for calculation of the stability coefficient in the design codes of various countries were compared and analyzed. Considering the characteristics of modern wood products,new and unified equations for calculation of the stability coefficient applicable to members made of various wood products were proposed,in which the traditional treatments of our country were kept. The constants in the unified equations were determined through regression with respect to different wood products,and the error in calculation of the stability coefficient was basically within 10%. Buckling tests of compression members made of SPF dimension lumber were conducted,and the buckling behaviour of the members was simulated with random finite element method. The results of the stability coefficient from tests,random finite element analysis and regression are well correlated,which verified the suitability and correctness of the proposed equations. The continuity and the consistency of design code method are kept and the need for design of modern timber structures satisfied.