【作者】 胡慧芳；

【导师】 向平；

【作者基本信息】 中南大学 ， 结构工程， 2025， 硕士

【摘要】 随着高速铁路的快速发展,列车-轨道-桥梁系统(TTBS)的动力响应与地震等极端条件下的行车安全问题日益凸显。实际工程中,车体参数离散性及桥梁材料性能变异等不确定性因素显著影响系统动态行为,确定性分析难以满足高安全标准需求,概率分析与非概率分析方法逐步兴起。针对实际工程场景缺乏精确概率分布信息的情况,本研究从非概率区间分析的角度探讨了考虑区间不确定性的TTBS动态响应和地震下列车运行性能,主要研究内容如下:(1)基于有限元法,构建高速列车-轨道-桥梁耦合系统动力分析模型,推导得到系统运动方程,并输入轨道不平顺与地震激励。与实验数据和经典算例对比,验证了地震下轮轨接触模型与车桥耦合振动模型的准确性和可靠性。进一步的,针对TTBS中参数未知但有界的特性,建立考虑区间不确定性的系统动力学方程。(2)提出应用于车桥系统的Chebyshev区间分析方法(CIM),结合多变量降维技术与Chebyshev多项式逼近,实现了TTBS系统动力响应边界的快速计算。数值结果表明,该方法在保证精度的同时可显著降低计算量,在多参数与大不确定水平场景下仍然具有显著优势。研究进一步揭示了区间参数种类、不确定水平及行车速度对系统动力特性的影响规律,强调了非概率不确定性量化在TTBS设计和安全评估中的重要性。(3)针对地震下行车安全问题,系统分析考虑区间不确定车桥系统的动态行为。验证了CIM在地震激励下TTBS系统中的有效性。结合脱轨系数、VSI等指标对地震下不确定桥上列车行车的安全性进行评估,考虑了地震动强度、行车速度及桥墩高度对安全指标的影响。结果表明,地震动强度与行车速度会提升加剧系统响应不确定性,PGA在0.2g以下,行车速度250km/h以内,行车安全性较高。桥墩高度的变化会影响系统不确定响应的峰值,10m墩高比较利于行车安全。此外,通过模拟列车通过徐变与横向变形桥梁的工况,明确了变形模式对脱轨风险的差异化影响机制。(4)针对震时列车刹车减速场景,建立减速制动模型,对比列车减速和匀速运行工况下的列车运行性能,发现减速制动可有效抑制地震引起的动力响应。进一步参数分析强调,列车减速初速度和摩擦系数都会增大不确定TTBS减速行车安全指标峰值,且减速初速度的影响更加明显。研究结果为地震应急制动策略的制定提供了一定的理论依据。图58幅,表8个,参考文献111篇更多还原

【Abstract】 With the rapid development of high-speed railway,the dynamic response of train-track-bridge system(TTBS)and the safety of train operation under extreme conditions such as earthquakes have become critical issues.In practical engineering,uncertainty factors such as discrete car body parameters and variation of bridge material properties significantly affect the system behaviour.Traditional deterministic analysis struggles to meet high safety standards,while probabilistic and non-probabilistic methods have gained prominence.In view of the lack of accurate probability distribution information in practical engineering scenarios,this study investigates TTBS dynamic responses and seismic performance from a non-probabilistic interval uncertainty perspective.The main contributions are as follows:(1)Based on the finite element method,a dynamic analysis model of high-speed TTBS is established.System motion equations were derived,incorporating track irregularities and seismic excitations.Validation against experimental data and classical examples confirmed the accuracy and reliability of the wheel-rail contact model and TTBS under seismic conditions.Furthermore,for the characteristic of unknown but bounded parameters in TTBS,the system dynamics equations considering the interval uncertainty are established.(2)A novel Chebyshev interval method(CIM)was proposed to analyze interval uncertainties in TTBS.By integrating multivariate dimension reduction techniques and Chebyshev polynomial approximation,rapid computation of dynamic response boundaries was achieved.Numerical results demonstrated that CIM maintains high precision while reducing computational costs,particularly effective in scenarios with multiple parameters and large uncertainty levels.The effects of interval parameter type,uncertainty magnitude and train speed on the dynamic characteristics are investigated,emphasising the importance of non-probabilistic uncertainty quantification in TTBS design and safety assessment.(3)The dynamic behaviour of interval-uncertain TTBS is systematically analysed for the safety of running under earthquake.The effectiveness of CIM in TTBS systems under seismic excitation is verified.The safety of train running on uncertain bridges under earthquake is evaluated by combining the derailment coefficient and VSI,and the effects of ground vibration intensity,running speed and abutment height on the safety indicators are considered.The results show that the ground shaking intensity and travelling speed will enhance to intensify the system response uncertainty,and the travelling safety is higher when the PGA is below 0.2g and the travelling speed is within 250km/h.The change of the height of the bridge pier affects the peak value of the system uncertainty response,and the 10m pier height is more favourable to the driving safety.In addition,by simulating the train passing through the working condition of the bridge with creep and lateral deformation,the mechanism of the deformation mode’s influence on the derailment risk is clarified.(4)A deceleration braking model is established for the scenario of train braking and deceleration during an earthquake,and the performance of train operation under deceleration and uniform speed is compared,and it is found that the deceleration braking can effectively inhibit the dynamic response induced by the earthquake.Further parametric studies highlighted that initial braking speed and friction coefficient uncertainties increase safety index peaks,with initial speed exerting a more pronounced influence.These findings provide theoretical support for formulating earthquake emergency braking strategies.更多还原