【摘要】 【目标】为了定量评估护栏在碰撞事件中的失效概率，对汽车-护栏碰撞过程中的护栏可靠度计算方法进行了研究。【方法】引入结构可靠性理论，将护栏系统视为受力结构，从概率的角度评估护栏在汽车碰撞下的阻挡性能。基于实测数据和文献调研，收集并分析了撞击速度、轴距、重心位置、前悬、后悬、车宽等15个基本随机变量，得到它们的概率分布模型。结合波形梁护栏防护汽车过程分析以及汽车-护栏碰撞非线性理论分析模型，以“护栏板达到极限拉应变时汽车碰撞点的横向速度为0”为护栏防护失效极限状态表征指标，构建了汽车与护栏碰撞问题的功能函数，提出了计算汽车-护栏碰撞事件中护栏失效概率及可靠指标的蒙特卡洛模拟方法。应用该方法对某路段的A级和SB级三波波形梁护栏进行可靠度分析。【结果】A级护栏的失效概率为5.3%,可靠指标为1.616,SB级护栏的失效概率为3.3%,可靠指标为1.838,后者优于前者，显示出更高的防护可靠性。【结论】基于概率的可靠度分析方法能够从结构可靠性角度量化不同等级护栏的性能差异，为公路护栏的性能评价及优化设计提供了具备理论基础和实践价值的新方法。更多还原

【Abstract】 [Objective]To quantitatively evaluate the failure probability of guardrails during collision, a theoretical study was conducted on the reliability calculation methods for guardrails in vehicle-guardrail collisions. [Method]The structural reliability theory was introduced, taking the guardrail system as a load bearing structure and evaluating its containment performance during collision from a probabilistic perspective. Based on the measured data and literature reviews, 15 fundamental random variables were collected and analyzed, e.g., impact speed, wheelbase, center of gravity position, front overhang, rear overhang, vehicle width. The probability distribution models of these variables were derived. The analysis on protection process of W-beam guardrails against vehicles and the nonlinear theoretical analysis model of vehicle-guardrail collisions were combined. The limit state of guardrail protection failure was characterized by the index, i.e., the lateral velocity of collision point was 0 when guardrail plate reached its ultimate tensile strain. A functional function for vehicle-guardrail collision was constructed. Monte Carlo simulation method was proposed to calculate the guardrail failure probability and reliability index in such events. The proposed method was applied to analyzing the reliability of A-level and SB-level W-beam guardrails on a certain highway section [Result]A-level guardrails exhibited the failure probability of 5.3%, and the reliability index of 1.616. SB-level guardrails exhibited the failure probability of 3.3%, and the reliability index of 1.838. The reliability of SB-level guardrails was higher than that of A-level guardrails. [Conclusion]The proposed probabilistic reliability analysis method could quantify performance differences among different guardrails from the perspective of structural reliability, providing a new approach with theoretical foundation and practical value for the performance evaluation and optimal design on highway guardrails.更多还原