Deformation Calculation Method of Reinforcement Part Considering the Randomness of the Welded Joint Stiffness

The hoisting safety and the difficulty of the main reinforcement connection are directly affected by stiffness of reinforcement parts. Quantifying the stiffness of reinforcement parts has become a key technology problem. Firstly, an independent mechanical solution model of three-dimensional rotational stiffness ($R_x$, $R_y$, and $R_z$) for the welded joints is proposed from the perspective of mechanical mechanism. Considering the influence of the rebar diameter, 105 sets of T-type welded reinforcement specimens and 2 types of loading devices were designed, and graded loading tests were performed. On this basis, considering the randomness of the rotational stiffness of the welded joints, a deformation calculation method for the welded reinforcement parts based on Monte Carlo random sampling is proposed, and six groups of two-dimensional (2D) reinforcement mats and six groups of three-dimensional (3D) reinforcement cages tests were performed. The results show that the rotational stiffness of the welded joints is random and has the Gaussian distribution characteristics. The rotational stiffness of the welded joints has a significant effect on the deformation of the welded reinforcement parts. Under the same welding conditions, the rotational stiffness of the welded joints increases with the increase of reinforcement diameter. Under the same reinforcement diameter, the three-dimensional rotational stiffness of the welded joints is in the order $R_x>R_z>R_y$. The cross-sectional area of the welded joint can better characterize the rotational stiffness. The verification test of welded reinforcement shows that the error of the calculation method proposed in this paper is within 10%, while the error of rigid connections and hinge connections are less than 30% and 130%, respectively.