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塔体构件的疲劳性能随服役期内降雨分布等环境腐蚀因素的改变而发生变化。为此,该文首先基于单点-成组法结合相关系数优化法推导了不同腐蚀方式作用下S-N曲线方程的参数表达式及其回归方法,并建议了相应的实现算法。基于此,建立了不同腐蚀方式的P-S-N曲线方程。同时,对相同腐蚀时间内3种腐蚀方式作用下的39根足尺Q345等边角钢构件进行了腐蚀疲劳试验,观察了试件在“浸泡-晾置”腐蚀方式中的腐蚀状态,研究了不同腐蚀方式中试件的疲劳破坏模式。然后,由试验结果分析了各腐蚀方式中疲劳寿命的变化规律,建立了相应的S-N曲线模型,给出了各腐蚀方式中反映S-N曲线参数随可靠度变化规律的表达式,并结合理论推导及参数分析建立了各腐蚀方式作用下Q345等边角钢构件的P-S-N曲面模型。最后,采用该模型探讨了不同腐蚀方式中Q345等边角钢构件疲劳寿命的变化规律,结果表明:1)相同腐蚀时间内疲劳荷载越小腐蚀方式对构件疲劳寿命的影响越明显;2)腐蚀越严重疲劳寿命随可靠度增加减小的幅度越大。
The fatigue performance of tower body components changes with the change of environmental corrosion factors such as rainfall distribution during the service period. Therefore, based on the single point-group method combined with the correlation coefficient optimization method, the paper first derives the parameter expression and regression method of S-N curve equation under different corrosion modes and proposes the corresponding algorithm. Based on this, a P-S-N curve equation with different corrosion modes was established. At the same time, corrosion fatigue tests were carried out on 39 full-scale Q345 equal-angle steel members under the same corrosion time under the three kinds of corrosion modes. The corrosion status of the specimens in the “immersion-drying” corrosion mode was observed. The fatigue failure mode of specimens in different corrosion modes. Then, the change law of fatigue life in each corrosion mode is analyzed from the test results. The corresponding SN curve model is established. The expression of the variation of SN curve parameters with reliability in each corrosion mode is given. Combining with the theoretical derivation and Parametric Analysis The PSN surface model of Q345 equilateral angle steel components under various corrosion modes was established. Finally, the model was used to investigate the variation of fatigue life of Q345 equilateral angle steel members in different corrosion modes. The results show that: 1) the smaller the fatigue load in the same corrosion time, the more obvious the influence of corrosion mode is on the fatigue life of the member; 2) Serious fatigue life decreases with increasing reliability.