@article{yu_chen_liu_2017, title={Advanced approaches to calculate recovery length and force redistribution in semi-parallel wire cables with broken wires}, volume={131}, ISSN={["1873-7323"]}, DOI={10.1016/j.engstruct.2016.10.017}, abstractNote={Two simplified models, including a theoretical approach and a finite element method (FEM) model, are proposed to calculate recovery length and study the force redistribution mechanism in a semi-parallel wire cable with broken wires. In the advanced theoretical model, the symmetrical construction and extrusion stress transfer characteristic of the semi-parallel wire cable are considered. The clench effect of the polyethylene sheath and the prestressed helical wire are considered in the derivation. The simplified FEM model can exhibit mechanical performance at both wire and cable levels. It uses helically placed beam elements to simulate twisted wires, divergently arranged rigid beam elements at the wire cross section to simulate extrusion effect, and nonlinear spring elements to consider the contact and friction between the helical wires. Results show that the recovery length is influenced by the compaction effect of wrapped sheath, as well as the twist angle and position of the broken wire. Under the symmetrical break condition, the recovery lengths calculated using the two methods are in a good agreement with each other, and force redistribution mainly results from the friction effect. Under the asymmetrical break condition, however, force redistribution is dominated by the induced unbalanced moment.}, journal={ENGINEERING STRUCTURES}, author={Yu, Yujie and Chen, Zhihua and Liu, Hongbo}, year={2017}, month={Jan}, pages={44–56} }
 @article{yu_chen_wang_2015, title={Effect of column flange flexibility on WF-beam to rectangular CFT column connections}, volume={106}, ISSN={["1873-5983"]}, DOI={10.1016/j.jcsr.2014.12.008}, abstractNote={Researches in the United States discovered different tension and shear flow patterns between wide flange (WF) column connections and box column connections. On the other hand, researches in Japan started many research on flexibility of column flange and proposed connection flexural moment strength based on the out-of-plane deformation for hollow section box column connections. However, both force flow pattern research and out-of-plane influence study in WF beam to rectangular concrete filled tube (CFT) column connections are insufficient. While due to the different composition and geometry configuration, direct extension of previous results is not feasible. This paper discusses the out-of-plane deformation at column flange, force flow pattern and shear and moment transfer efficiency of WF-beam to rectangular CFT column connection. Results show that both Poisson effect and flexibility of column flange will lead to a change on force flow pattern in beam–column junction region and inefficient moment transferring ability through beam web, resulting in a high level of hydrostatic stress demand at beam flanges. Weld access hole, thickness of column flange and diaphragm and web connection details all have certain effect on column flange bending stiffness and the transfer efficiency of beam web. A flexural strength evaluating method for the rectangular CFT column connection based on the out-of-plane deformation is also presented.}, journal={JOURNAL OF CONSTRUCTIONAL STEEL RESEARCH}, author={Yu, Yujie and Chen, Zhihua and Wang, Xiaodun}, year={2015}, month={Mar}, pages={184–197} }
 @article{yu_chen_wang_2015, title={Investigation and evaluation of a novel technique on CFRT column connection}, volume={113}, ISSN={["1873-5983"]}, DOI={10.1016/j.jcsr.2015.06.014}, abstractNote={This study investigated the effect of an innovative technique, heat treatment, on Q345B steel, which is generally used in China, and the application potential of this technique for H-beam moment connections to concrete filled rectangular steel tube (CFRT) column. A heat-treating process with ultra-high temperature heating and subsequent controlled slow cooling could have a weakening effect on steel strength. The effect of this heat-treating process on steel was investigated through a series of material tests on Q345B steel (Chinese standard). The Chaboche hysteresis material model was selected and calibrated to better describe the strength behavior under cyclic loading, and was then used for subsequent seismic simulations. This technique can be utilized to improve the seismic performance of connections by locally heat-treating the beam section (HBS), and then inducing the plastic hinge away from the critical region. The effect of HBS was investigated on two common CFRT column connections in China, namely, through-diaphragm and internal-diaphragm CFRT column connections. Results showed that the novel heat-treating process also had a significant weakening effect on Chinese Q345B steel. The hysteresis behavior of steel was different from the monotonic performance. The Chaboche model can effectively describe the hysteresis properties. The application of HBS succeeded in inducing plastic strain developed in the heat-treated region, and can reduce strain concentrations without significant connection moment strength loss.}, journal={JOURNAL OF CONSTRUCTIONAL STEEL RESEARCH}, author={Yu, Yujie and Chen, Zhihua and Wang, Xiaodun}, year={2015}, month={Oct}, pages={195–208} }
 @article{yu_chen_liu_wang_2014, title={Finite element study of behavior and interface force conditions of seven-wire strand under axial and lateral loading}, volume={66}, ISSN={["1879-0526"]}, DOI={10.1016/j.conbuildmat.2014.05.009}, abstractNote={Abstract Although numerous FE models have been proposed to analyze the mechanical behavior of simple strands, they seldom examine the contact condition and lateral loading behavior that may influence local stress distribution and lifetime performance. In this study, serial 3D FE models of a seven-wire strand were developed to discover the interface mechanism under longitudinal and lateral loading. A partially restrained model was proposed and carefully studied. Friction minimally influenced longitudinal stiffness and had a limited effect on lateral behavior. FEM analysis predicted uneven stress distribution under lateral loading simulation. Both strand bending phase and wire bending phase were observed near the termination. Microslip and contact line migration mainly occurred between helical wires.}, journal={CONSTRUCTION AND BUILDING MATERIALS}, author={Yu, Yujie and Chen, Zhihua and Liu, Hongbo and Wang, Xiaodun}, year={2014}, month={Sep}, pages={10–18} }