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为探索预应力结构在侵蚀环境作用下的工作机理和寿命,对冻融后疲劳侵蚀环境下结构疲劳寿命的主要因素及相对关系进行研究。在试验研究的基础上,采用统计分析的理论,推导出多元曲线关系式;通过大量试验数据,测定和分析经受不同冻融次数T、预应力等级S的试验构件的疲劳寿命,并建立预冻融疲劳寿命影响系数C的模型。结果表明:随着冻融次数T的增加,同一系列预应力构件的预冻融疲劳寿命影响系数C不断下降;而当冻融次数T一定时,预冻融疲劳寿命影响系数C与预应力度S表现出较为复杂的往返性关系,高冻融次数对较高预应力构件的预冻融疲劳寿命影响系数C的影响较大。所得模型可在已知环境和结构等条件下,求出给定可靠概率的疲劳寿命影响系数值和疲劳寿命预测值。
In order to explore the working mechanism and life expectancy of the prestressed structure under the action of erosion environment, the main factors and the relative relationship between the fatigue life of the structure under fatigue and erosion after freezing and thawing were studied. On the basis of the experimental study, the statistical analysis theory was used to derive the multivariate curve. Through a large number of experimental data, the fatigue life of test components subjected to different numbers of freeze-thaw cycles T and prestressing grade S was determined and analyzed. Fatigue life model with influence coefficient C. The results show that with the increase of the number of freeze-thaw cycles T, the influence coefficient C of pre-freeze-thaw fatigue life of the same series of prestressed components decreases continuously. When the number of freeze-thaw cycles T is constant, the influence coefficient of pre-freeze- S showed a more complex reciprocal relationship, and the number of high freeze-thaw cycles had a greater effect on the coefficient of influence C of pre-freeze-thaw fatigue life of higher prestressed components. The obtained model can obtain the fatigue life influence coefficient value and the fatigue life prediction value for a given reliable probability under known conditions and structures.