考虑节点刚度随机性的焊接钢筋部品变形计算方法研究

Research on Methods to Calculate Deformation of Finished Reinforcement Products Considering Stochastic Stiffness of Welded Joints

为量化钢筋部品刚度,从受力机理角度出发,基于试验和理论分析,提出考虑刚度随机性的焊接钢筋部品变形计算方法。从受力机理的角度提出三向转动刚度独立力学求解模型,考虑钢筋直径的影响,设计了105组T形焊接钢筋试件及两类加载固定试验装置,开展分级加载试验;在此基础上,考虑焊接节点转动刚度随机性,提出基于蒙特卡洛随机抽样的焊接钢筋部品变形计算方法,并分别开展了6个焊接钢筋网片和6个钢筋块体试验进行验证。结果表明:钢筋焊接节点刚度与钢筋直径有关,当焊接条件相同时,钢筋直径越大,焊接节点刚度越大;同一钢筋直径组合的焊接节点转动刚度基本符合正态分布,3个方向的转动刚度R x>R z>R y;钢筋焊接节点刚度与焊接节点断面面积基本呈线性关系;竖筋和横筋连接节点刚度对钢筋部品变形影响显著,所采用的节点刚度取值方法计算的焊接钢筋部品变形偏差均在10%以内,与传统刚接和铰接方法相比,变形计算精度大幅提高,变形计算方法合理。

A method to calculate deformation of finished reinforcement products is proposed,aiming to quantify the stiffness of the reinforcement products.The method has been developed on tests and theoretical analysis,taking into account the force mechanism of reinforcement as well as the stochastic stiffness of welded joints.A stiffness mechanical model of three directions was built up from the perspective of force mechanism.Considering the influence of reinforcement diameter,105 groups of reinforcement specimens with T welded joints and two types of fixing setups for load application were designed to carry out graded loading tests.Furthermore,considering the stochastic rotational stiffness of welded joints,a method to calculate the deformation of finished reinforcement products that is developed from Monto Carlo simulation was proposed,which was subsequently verified by tests of six groups of reinforcement mats and six groups of reinforcement cages.It is shown that the stiffness of the welded joints and the reinforcement diameter are related,under the same welding condition,larger reinforcement diameter leads to greater stiffness of welded joints.The rotational stiffness of welded joints consisting of reinforcing bars of same diameter conform to normal distribution.The rotational stiffnesses in three directions,namely R x,R z,and R y,were not the same(R x>R z>R y).The stiffness of a welded joint is basically in linear relationship with its cross-sectional area.The stiffnesses of welded joints of vertical and transverse reinforcing bars are critical to the deformation of finished reinforcement products.The deformation calculation error of the finished reinforcement products by the proposed method is within the range of 10%,which is of higher calculation precision than that for the traditional rigid connection and hinged connection,and is an effective method for deformation calculation of finished reinforcement products.