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| Abstract: |
| Corrosion is a primary cause of the slippage of friction-type high-strength bolted (FHSB) T-stub connections. This paper attempts to quantify the residual capacity of FHSB T-stub connections with corroded nuts. Firstly, corrosion simulation tests were conducted on 48 manually cut nuts to find out the relationship between the damage degree of nut section and the residual clamping force (RCF) of bolt. Then, static load tests were carried out on 24 FHSB T-stub connections with nuts of different degrees of damage to obtain the failure modes. By finite-element (FE) models, a comparative analysis was performed on the initial friction load (IFL) and ultimate strength (US) of each connection with corroded nuts. Finally, the parameters of 96 FE models for FHSB T-stub connections were analyzed and used to derive the calculation formulas for the degree of damage for each nut and the IFL and US of each connection. The results show that the RCF decay of a bolt is a quadratic function of the equivalent radius loss ratio and the shear failure after nut corrosion; the IFL of each connection had a clear linear correlation with the RCF of the corresponding bolts, and the correlation depends on the applied load and static friction on connecting plate interface induced by the clamping force; the static friction had little impact on the US of the connection; the proposed IFL and US formulas can effectively derive the residual anti-slip capacity of FHSB T-stub connections from the degree of damage of the corroded nut section. The research results provide a scientific basis for the replacement and maintenance of corroded bolts of FHSB T-stub connections. |
| Key words: nut corrosion T-stub connection high-strength bolt sectional damage residual clamping force (RCF) anti-slip capacity |
| DOI：10.11916/j.issn.1005-9113.21053 |
| Clc Number:U443.35; U445.72 |
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| Descriptions in Chinese: |
| 螺母截面腐蚀损伤后摩擦型高强螺栓T形接头剩余承载力 徐刚年1，蔺宝垚2，杜业峰3 （ 1.山东交通学院 交通土建工程学院， 济南 250357； 2.交通运输部公路科学研究所， 北京 100081； 3.山东大学 土建与水利学院， 济南 250061） 摘要：腐蚀是引起摩擦型高强螺栓（FHSB）T形接头滑移的主要原因之一。为定量评估螺母截面腐蚀损伤后FHSB T形接头的剩余承载力，本文首先对48个螺母进行了人工切割模拟腐蚀试验，找出了螺母截面损伤程度与螺栓剩余夹紧力之间的关系。然后，对24个具有不同螺母截面损伤程度的FHSB T形接头进行静力试验，并建立了试验接头的数值模型，对比和验证了接头的破坏模式、初始滑移荷载及极限荷载。最后，采用数值模拟法对96个接头模型进行参数分析，推导出连接螺母在不同截面损伤下接头的初始滑移载荷和极限强度计算公式。结果表明：本文设计的螺母截面损伤接头均发生剪切破坏，螺栓夹紧力随等效半径的损失呈二次幂函数衰减；初始滑移荷载的大小取决于施加在接头连接板上的压力荷载和螺栓夹紧力提供给接头接触面的静摩擦力，与连接螺栓的剩余夹紧力存在明显的线性相关性，然而静摩擦力对接头的极限强度影响不大；本文提出的初始滑移荷载和极限强度计算公式可用于评估螺母截面腐蚀损伤后FHSB T形接头的抗滑移承载力，为FHSB T形接头腐蚀螺母的更换和维修提供了科学依据。 关键词：螺母腐蚀；T形接头；高强螺栓；截面损伤；剩余夹紧力；抗滑移承载力 |
