考虑材料性能退化影响的锈蚀水工组合梁时变可靠度分析

Time-varying Reliability Analysis Method of Corroded Hydraulic Composite Beam Considering Material Performance Degradation

随着运行年限的增加,水工组合梁在外部环境和荷载的作用下材料力学性能会发生一定程度的退化,基于时变理论对水工组合梁的安全可靠度分析已成为其安全评价的重要内容。为此,采用Monte Carlo随机有限元法,结合材料性能退化规律,分析研究了锈蚀水工组合梁时变可靠度规律。通过工程算例分析,得到了材料性能随时间线性衰减情况下水工组合梁的屈服强度和弹性模量,研究了材料性能退化与否对水工组合梁失效概率和可靠度的影响,并对计算所得到的失效概率和可靠度进行数值拟合。结果表明,水工金属结构屈服强度和弹性模量随锈蚀程度的加深而减小,且与失重率呈线性关系;无论是否考虑材料性能退化规律,水工组合梁可靠度指标均为线性变化,可根据拟合后的线性规律计算出任意时段水工组合梁可靠度指标。

With the increase of service life, the mechanical properties of hydraulic composite beams will be degraded to some extent under the action of external environment and load. The safety and reliability analysis of hydraulic composite beams based on time-varying theory has become an important part of its safety evaluation. Monte Carlo stochastic finite element method was used to analyze the time-varying reliability law of corroded hydraulic composite beams combined with the material performance degradation law. Through the analysis of engineering examples, the yield strength and elastic modulus of hydraulic composite beams under the condition of linear attenuation of material properties over time were obtained. The impact of material properties degradation on the failure probability and reliability of hydraulic composite beams was studied. The failure probability and reliability obtained by calculation were numerically fitted, and the corresponding calculation rules were obtained.