工程结构时变失效概率分析

用泊松脉冲随机过程模拟机车车辆荷载,考虑抗力随时间的变化,给出工程结构时变失效概率的计算公式。定性分析抗力衰减函数、荷载平均发生率和结构服役时间对失效概率的影响。结果表明,在其他因素确定的情况下,荷载发生频率的增大、结构服役时间的延长及抗力的衰减均会导致失效概率增加,其中抗力衰减引起结构失效概率的增加更明显。因此在服役过程中需对结构进行定期的检测维修,以确保其可靠性。

Time-dependent Failure Probability Analysis of Engineering Structure

The formula for calculating failure probability of engineering structure is given, with loading of locomotive vehicle modeled as Poisson impulse process and time-dependent variety of resistance considered. The influences on failure probability by resistance degradation function, average occurrence rate of loading and service time are analyzed qualitatively. The conclusions show that with other factors unchanged, the failure probability increases with the following factors: the average occurrence rate of loading increasing, the service time extending and the degradation of resistance. Resistance degradation is the most important factor. As a result, periodic survey and maintenance must be adopted to ensure the reliability.