【作者】 李卫；

【导师】 张怀亮；

【作者基本信息】 中南大学 ， 机械设计及理论， 2024， 博士

【摘要】 隧道硬岩掘进机(TBM)是用于隧道施工建设的技术密集型工程装备,液压系统因其高压,高功率,空间占用小等优点,在TBM中被大面积使用。液压管道是液压系统动力传输的关键部件,而液压直管是液压管道中最典型且分布最多的管道类型,其动力学特性直接影响液压系统的功能实现。TBM工作过程中会产生强烈的随机振动,振动会通过主梁和支撑传递到液压直管上,使液压直管工作在随机振动环境中。液压泵和外激励的作用会使液压直管内的流体产生脉动,由于流固耦合作用,流体的脉动也会引发液压直管的振动。因此,TBM液压直管在工作中会产生强烈的振动,严重时会导致管道发生破坏,从而造成严重损失。针对这一问题,本文结合液压直管的实际工况,建立考虑基础随机振动和脉动流共同作用下的TBM液压直管非线性动力学模型,对TBM液压直管的动力学特性展开研究。主要的研究内容如下:(1)建立考虑几何非线性、基础随机振动和管内流体脉动的TBM液压直管随机非线性动力学模型。根据流固耦合理论和Euler-Bernoulli梁模型,利用牛顿法建立了随机振动和脉动流同时作用下的TBM液压直管随机非线性动力学模型,采用第二类随机谐和函数表示直管基础随机振动过程样本。通过对所建立的非线性动力学模型进行离散化和无量纲化处理,得到了简化形式的非线性动力学微分方程组。后续通过实验验证了所建立的动力学模型的正确性。(2)研究TBM液压直管随机动态响应的求解方法及主要参数对直管响应的影响。推导了基于Newmark-β积分格式的时域显式迭代算法,用于求解管道随机非线性动力学模型(方程),在此基础上提出了管道动态响应分析的时域显式随机分析方法,并通过数值计算实例验证了该方法的正确性。对管道的位移响应,速度响应和应力响应进行了统计分析,得到了各响应的均值,标准差和平均峰值,详细分析了流体流动参数,随机振动功率谱密度和TBM液压直管结构参数等主要参数对管道动态响应的影响规律。(3)研究TBM液压直管随机动态稳定概率及主要参数对直管随机动态稳定性的影响。推导了基于能量准则的直管随机动态稳定性判据,结合概率密度演化法,计算了直管随机动态稳定概率。该方法既考虑了管道自身结构特性,也考虑了外部载荷和阻尼作用,并采用数值计算实例验证了所提出的方法的正确性。详细分析了直管结构参数、流体流动参数、阻尼和随机振动参数等对直管随机动态稳定概率的影响规律,得到了直管结构参数的随机动态稳定性区域。(4)研究TBM液压直管随机分岔及主要参数对直管随机分岔特性的影响。根据时间上平均的稳态概率密度定义和随机P-分岔理论,采用概率密度演化法求得了TBM液压直管位移响应的时间上平均的稳态概率密度(ARSPDF)曲线图(分岔图)。通过将分析结果和数值计算实例结果进行对比,验证了分析结果的正确性。分析了直管结构参数、流体流速和压力、随机振动参数和阻尼等主要参数对直管随机分岔特性的影响。(5)搭建TBM液压直管随机振动实验台,验证所建立的动力学模型及分析结果的正确性。搭建了随机振动环境下TBM液压直管振动实验平台,以固支-固支管道为实验对象,测量了管道的应力,速度和位移,并对测量结果进行统计分析,得到响应的平均峰值。通过相似理论得到了实际工况中,大尺寸的液压直管的响应平均峰值的实验相似换算值。在相关参数一致的前提下,将实验值及实验相似换算值与数值计算结果进行对比分析,并对实验值及实验相似换算值和数值结果之间的误差进行分析和总结。分析结果表明,实验测试结果和数值计算结果之间的误差绝对值均小于12%,实验相似换算结果和数值计算结果之间的误差绝对值均小于16%,误差大小在合理范围内,证明所建立的动力学模型和分析结果是正确的。最后对误差来源进行了详细分析。综上所述,本研究可为TBM液压直管的随机非线性振动分析和减振设计提供理论支撑和技术参考。液压直管是一种典型的输流管道,而输流管道是一种重要的工程结构,在很多领域都有广泛的应用,例如热交换器管道、输油管、输水管和碳纳米管等。因此,本文的研究也可为其它领域中输流管道的随机非线性动力学分析提供参考。图102幅,表27个,参考文献189篇更多还原

【Abstract】 Tunnel Boring Machine(TBM)is a technology-intensive engineering equipment used in tunnel construction.Hydraulic system is widely used in TBM due to its high pressure,high power,and small space occupation advantages.Hydraulic pipe is the critical component of hydraulic system power transmission.Hydraulic straight pipe is the most typical and distributed pipe type in the hydraulic system,and its dynamics directly affect the realization of the function of the hydraulic system.In the process of TBM operation,strong random vibration will be generated,and the vibration will be transmitted to the hydraulic straight pipe through the main beam and support,so that the hydraulic straight pipe will work in the random vibration environment.The action of hydraulic pump and external excitation will make the fluid pulsate in the hydraulic straight pipe.Due to the fluid-structure coupling,the fluid pulsation will cause the hydraulic straight pipe vibration.Therefore,the TBM hydraulic straight pipe will produce strong vibration during operation,which will lead to the destruction of the pipe in serious cases,thus causing serious damage.To solve this problem,combined with the actual working condition of the hydraulic straight pipe,a nonlinear dynamic model of the TBM hydraulic straight pipe was established considering the random vibration and pulsating flow of the foundation,and the dynamic characteristics of the TBM hydraulic straight pipe were studied.The main research contents are as follows:(1)The stochastic nonlinear dynamic model of TBM hydraulic straight pipe considering geometric nonlinearity,random vibration of foundation,and pulsating flow velocity in the pipe is established.The stochastic nonlinear dynamic model of TBM hydraulic straight pipe under the simultaneous effect of random vibration and pulsating flow velocity is established by using Newton’s method according to the fluid-structure interaction theory and Euler-Bernoulli beam model.A second class of random harmonic functions is used to represent a sample of the underlying random vibration process of a straight pipe.A set of differential equations in simplified form is obtained by discretizing and dimensionless processing of the established nonlinear dynamic model.Finally,the correctness of the established dynamic model is verified by experiments.(2)The solution method of the stochastic dynamic response of the hydraulic straight pipe of TBM and the influence of the main parameters on the response of the straight pipe are investigated.A time-domain explicit iterative algorithm based on the Newmark-βintegral format is derived for solving the stochastic nonlinear dynamics model(equations)of the pipeline,and a time-domain explicit stochastic analysis method is proposed for the dynamic response analysis of the pipeline,which is verified by numerical calculation examples.The pipe’s displacement response,velocity response,and stress response are statistically analyzed,and each response’s mean,standard deviation,and average peak value are obtained.The influences of fluid parameters,power spectral density of random vibrations,and structural parameters on the dynamic response characteristics of the pipe with different boundary conditions are analyzed in detail.(3)Research on the random stability probability of TBM hydraulic straight pipe and the influence of main parameters on the random stability of straight pipe.The random dynamic stability criterion of the pipe based on the energy criterion is deduced,and the random dynamic stability probability of the pipe is calculated by combining it with the probability density evolution method.The numerical method considers the pipe’s structural characteristics,external loads,and damping effects.Calculation examples are used to verify the correctness of the analyzed results.The influence laws of pipe structural parameters,fluid parameters,damping,and random excitation parameters on the stochastic dynamic stability probability of the pipe are analyzed in detail,and the stochastic dynamic stability region of the pipe is obtained.(4)The random bifurcation of TBM hydraulic straight pipe and the influence of main parameters on the random bifurcation characteristics of straight pipe are studied.According to the theory of probability density averaged over time and the theory of random P-bifurcation,the time-averaged steady probability density function(ARSPDF)curve diagram(bifurcation diagram)of the TBM hydraulic straight pipe is obtained by using the probability density evolution method.The correctness of the analytical results is verified by comparing the analytical results with the numerical calculation example results.The effects of the main parameters such as pipe structural parameters,fluid velocity and pressure,excitation parameters and damping on the random bifurcation characteristics of the pipe are analyzed.(5)The experimental platform of random vibration of TBM hydraulic straight pipe was built to verify the correctness of the dynamic model and dynamic response analysis results.The experimental TBM hydraulic pipe vibration platform was built under a random vibration environment.Taking the clamp-clamp pipe as the experimental object.The stress,velocity,and displacement of the pipe were measured and the measurements were statistically analyzed to obtain the mean peak value of the response.The experimental similarity conversion values of the mean peak value of the response of a large-size hydraulic straight pipe in the actual working condition are obtained by the similarity theory.The experimental values and the experimental similar conversion values are compared and analyzed with the numerical calculation results,and the errors between the experimental values and the experimental similar conversion values and the numerical results are analyzed and summarized.The analysis results show that the absolute value of the errors between the experimental test results and numerical calculation results are all less than 12%,and the absolute value of the errors between the experimental similar conversion results and numerical calculation results are all less than 16%,and the magnitude of the errors is within a reasonable range,which proves that the established dynamic model and analysis results are correct.Finally,the source of error is analyzed in detail.In summary,the research results can be used as theoretical support and technical reference for analyzing and designing random nonlinear vibration of TBM hydraulic straight pipes and flow transfer pipes under similar working conditions.Since the hydraulic straight pipe is a typical fluid-conveying pipe,and the fluid-conveying pipe is an important engineering structure that has been widely used in many fields,such as heat exchanger pipes,oil pipes,water pipes and carbon nanotubes.Therefore,the study in this thesis can also provide a reference for the analysis of stochastic nonlinear dynamics of fluid-conveying pipes in other fields.更多还原