Anchor Behavior of One-Side Bolt with Flip-Top Collapsible Washer

Abstract

With the development of blind bolts that can be installed from the outer side of a section, the application of steel pipe hollow sections in prefabricated structures has become possible. The novel one-side bolt with a flip-top collapsible washer (FTW-OSB) is proposed, which can fold the washer at the end of the bolt to achieve a simple and efficient installation. Firstly, the components and installation process of the FTW-OSB are introduced. Additionally, axial tensile tests were carried out on three types of new bolts, and the failure mode, load–displacement curve, and ultimate capacity were analyzed. Based on this, the finite element model was verified, and through a series of finite element parameter analyses, the influence of washer size and construction, the friction coefficient, and the contact surface size on the new bolt were analyzed and optimized. The results show that the L-shaped washer can prevent washer rotation and has better anchoring performance than the I-shaped washer. The washer thickness, height, and upper contact surface size are the key factors affecting the anchoring performance of the FTW-OSB bolt. Among these factors, when the washer thickness increases from 0.1 d0 to 0.3 d0, the ultimate capacity and initial stiffness of the FTW-OSB bolt increase by 136.5% and 100.3%, respectively. The lower contact surface size and friction coefficient can be ignored. The failure model of the FTW-OSB is mainly washer shear failure and bolt tension failure. By effectively adjusting the washer thickness, side wall height, and upper contact surface size, shear failure of the washer can be avoided and an anchoring performance can be achieved that is the same as that of the same type of 10.9-grade ordinary high-strength bolt.