【作者】 甄晓霞；

【导师】 王荣辉；

【作者基本信息】 华南理工大学 ， 结构工程， 2010， 博士

【摘要】 沥青混凝土作为大跨径钢箱桥梁通用的铺装材料,具有保护桥面板,提高桥梁使用寿命、行车舒适性与安全性,减少振动与噪声等优点,但由于不同桥型结构体系的受力特点不同及铺装材料与钢桥面板性能差异大等原因,铺装层开裂、铺装层与钢板脱层、车辙破坏等病害非常普遍,本文结合工程实例,开展大跨径钢箱桥面铺装体系关键力学问题研究,为铺装体系的优化设计与病害分析提供新的计算方法和思路。论文主要完成了以下工作:(1)以珠江黄埔大桥钢箱梁悬索桥为工程背景,进行整桥非线性分析,并选取结构中受力最不利的局部梁段,建立局部梁段的板壳及实体单元有限元模型,通过引入梁单元模型与板壳实体单元模型界面上的位移约束条件,建立混合单元模型,进行有限元分析计算,并将分析结果与局部铺装体系的有限元分析结果进行比较,为进一步进行局部铺装体系层间接触分析提供模型。(2)构造了一种12节点实体板单元模拟钢桥面沥青混凝土铺装层,用8节点实体单元模拟钢桥面板,通过Goodman单元模拟两种实体板单元之间的接触状态,形成一种新型的组合单元,该单元能较好地反映各种沥青铺装层和桥面板的接触状态;通过UPFs的二次开发技术,在大型通用有限元软件平台上,完成了组合单元的实现,在此基础上对钢桥面铺装体系各主要力学指标随层间接触状态变化的敏感性进行详细研究,确定铺装层力学性能指标的关键因素,得到相应力学指标与层间切向劲度系数的关系表达式,给出铺装层材料及钢桥面板结构参数的合理取值范围,弥补了只考虑层间完全连续状态或层间滑动状态确定设计参数而导致的两种极端状态,为钢桥面铺装体系的设计提供理论依据。(3)根据蠕变函数与松弛函数之间的微分型本构方程,对蠕变试验数据非线性拟合得到用多项式描述的蠕变曲线,对其进行Laplace变换与逆变换,有效地实现了蠕变曲线向松弛曲线的转换;应用该方法将环氧沥青混凝土蠕变试验得到的蠕变柔量转换为松弛模量,应用计算机数值模拟方法,分析温度变化、加卸载条件变化及层间接触状态变化对环氧沥青混凝土及SMA10改性沥青混凝土铺装体系受力性能的影响规律。(4)在对沥青混凝土铺装材料疲劳试验及蠕变试验过程中的耗散能进行分析的基础上,将疲劳试验中结构上施加的荷载分解为产生蠕变效应的荷载和产生疲劳效应的荷载,分别考虑蠕变与疲劳损伤函数的演化过程,引入蠕变-疲劳损伤因子,计算蠕变和疲劳荷载作用下的损伤能耗,提出了由复合梁疲劳试验预测沥青混凝土材料蠕变性能的方法,弥补了现有蠕变试验只能反映材料蠕变性能而无法反映结构约束条件作用的不足,更为合理地描述了在钢板约束作用下沥青混凝土铺装材料的蠕变性能;通过常温下一个实例验证了该方法的可行性,为合理分析复合梁铺装材料蠕变性能提供理论依据,并提出采用能量法建立的的铺装层应力-疲劳寿命关系式。更多还原

【Abstract】 As pavement material,asphalt mixture has advantages such as protecting bridge deck, prolonging service life,promoting crane comfortability,reducing vibration and noise, though different mechanical characteristics of different bridge types and variance between pavement materials and steel decks cause pavement cracking,disengagement between pavement and deck,rut and other early damage. This paper makes researches on the pavement system of long-span steel box bridges,provides new analysis method and thinking on optimization and damage analysis of pavement system. Main research works in this thesis are as followed:(1) Nonlinear analysis of ZhuJiang HuangPu steel suspension bridge was proceeded, a local box beam with the biggest bending moment was extracted and a finite element model of it was built, displacement constraints conditions on the interface of beam model and shell-solid model were introduced, finite element analysis was proceeded, results were compared with finite element analysis results of local pavement systems.(2) A 12-nodes solid shell element was constituted and a method of analyzing nonlinear contact problem was adopted. Spatial analysis model was constituted by 8 nodes solid shell element, Goodman contact element and 12 nodes solid shell element. The user program was implemented through UPFs secondary exploitation technique of ANSYS software. Spatial pavement system analysis model was constituted. Detail analysis was carried out on sensitivity of pavement system mechanical indexes according to contact state change and least-squares method was used to express mathematical relation between tangential stiffness coefficient and mechanical indexes. According to different material parameters and structure parameters, pavement system was analyzed and incomplete contact conditions were considered. Key factors that can reflect mechanical properties indexes were defined, reasonable range of pavement material and steel bridge deck were determined.(3) A changing method of relaxation and creep function of asphalt mixture was proposed under corresponding fundamental relationship of relaxation curve and creep curve. Combined with characters of steel deck pavement system, detailed research on the visco-elastic response of steel bridge pavement which endured the automobile load was implemented. Quasi-elastic method was used to analyse basic law of pavement system mechanical response according to different temperatures and different contact conditions between steel deck and pavement. Variation pattern of mechanical response was analysed under the conditions of loading and unloading.(4) Leading coupling effect of creep damage and fatigue damage into asphalt mixture creep model, expression of creep-fatigue damage factor was given. Corresponding dissipated energy relations between steel deck composite beam fatigue test and creep test in constant stress was established and creep feature forecast method of asphalt mixture was proposed by composite beam fatigue test. Stress-fatigue life relation of pavement material equation was proposed by energy methods.更多还原