胶合木-混凝土组合梁斜交螺钉连接件抗剪刚度计算方法研究

In order to develop the calculation method of shear stiffness for inclined cross screws in glulam-concrete composite beams, seven groups of the inclined cross screws, a total of twenty-one push-out tests were carried out. Based on the push-out test result, the load-slip curves of inclined cross screws were achieved, the influences of concrete strength, screw diameter, embedded angle of screws on shear stiffness of inclined cross screws were analyzed, the mechanical behavior of inclined cross screws in glulam-concrete composite beams were discussed in detail. Based on the theory of a beam on a two-dimensional elastic foundation, a model for calculating the shear stiffness of the inclined cross screws was proposed. The results show that the shear stiffness is improved effectively with increased screw diameter. The shear stiffness is reduced with the decrease of angle of the inclined cross screws to the beam. The calculation method indicates that the screws diameter, embedded angle of screws, shear stiffness of screws, and foundation modulus of timber parallel and transverse to the grain are the main influence factors of shear stiffness. The calculated results were in good agreement with the experimental results.