本文選題：RC橋面板　切入點(diǎn)：隨機(jī)車流　出處：《哈爾濱工業(yè)大學(xué)》2016年碩士論文　論文類型：學(xué)位論文

【摘要】：隨著中國(guó)經(jīng)濟(jì)快速穩(wěn)定的增長(zhǎng),中國(guó)公路承載的交通量迅猛增加,超載問題日益突出,導(dǎo)致車輛荷載作用下公路混凝土橋梁出現(xiàn)了大量的疲勞問題。在以往的橋梁結(jié)構(gòu)設(shè)計(jì)中,主要是以承載能力作為橋梁結(jié)構(gòu)安全的控制指標(biāo),輕視了在反復(fù)荷載作用橋梁結(jié)構(gòu)的耐久性指標(biāo)。工程實(shí)踐表明運(yùn)營(yíng)條件下直接承受車輛荷載作用的混凝土橋面板最易發(fā)生疲勞損傷和破壞,從而影響橋梁結(jié)構(gòu)整體的使用性能。為此,本文以混凝土橋面板為對(duì)象,開展隨機(jī)車輛荷載作用下混凝土橋面板的疲勞壽命分析方法研究。首先,編制方程維度時(shí)變的隨機(jī)車流與橋梁耦合振動(dòng)分析程序算法。依據(jù)某公路的實(shí)際交通量觀測(cè)和調(diào)查數(shù)據(jù),將該公路上的車輛類型歸納整理,建立了典型車輛荷載庫(kù),確定了交通量統(tǒng)計(jì)中的主要參數(shù),如車型比例、車輛間距和車輛軸重等所服從的概率分布,模擬生成隨機(jī)交通流。采用拉格朗日原理,構(gòu)建了典型車輛的運(yùn)動(dòng)方程。選取公路中常見簡(jiǎn)支轉(zhuǎn)連續(xù)裝配式預(yù)應(yīng)力鋼筋混凝土T梁橋,建立了其ANSYS有限元模型并進(jìn)行模態(tài)分析。依托算例,分析了車輛類型、車速和橋面不平整度狀況對(duì)車載下橋梁結(jié)構(gòu)動(dòng)力沖擊效應(yīng)的影響,并與規(guī)范計(jì)算結(jié)果進(jìn)行了對(duì)比。然后,建立基于連續(xù)損傷力學(xué)的RC橋面板疲勞壽命分析預(yù)測(cè)模型和分析方法。研究了鋼筋混凝土疲勞損傷機(jī)理,分析指出了控制橋面板疲勞破壞的主要因素。對(duì)比分析了線性疲勞損傷累積理論和非線性疲勞損傷累積理論的特點(diǎn)和各自優(yōu)劣勢(shì)。依托算例,計(jì)算得到了隨機(jī)車載下橋面板疲勞熱點(diǎn)位置的動(dòng)應(yīng)力時(shí)程,運(yùn)用雨流計(jì)數(shù)法得到應(yīng)力幅和平均應(yīng)力,應(yīng)用兩種不同的疲勞損傷模型對(duì)橋面板進(jìn)行了疲勞壽命預(yù)測(cè)分析。最后,研究了交通量增長(zhǎng)、車輛超載和橋面狀況劣化等因素對(duì)橋面板疲勞損傷的影響。采用灰色模型構(gòu)建了交通量增長(zhǎng)模型,分析了不同交通量下橋面板應(yīng)力幅的變化規(guī)律和在固定時(shí)間節(jié)點(diǎn)改變交通量對(duì)橋面板疲勞壽命造成的影響。依據(jù)我國(guó)各主要公路的超載現(xiàn)狀調(diào)查數(shù)據(jù),指出各車輛類型的超載比例和超載率。提出含有超載車輛的隨機(jī)車流的模擬方法,分析在該車隊(duì)作用下橋面板應(yīng)力幅的變化規(guī)律。分析了含有超載車輛的隨機(jī)車流作用在橋梁結(jié)構(gòu)使用壽命的初期和中期,對(duì)橋面板疲勞壽命的影響。調(diào)查研究橋面狀況的劣化規(guī)律,按照模擬的橋面狀況分析在隨機(jī)車載作用下疲勞熱點(diǎn)應(yīng)力幅的改變和預(yù)測(cè)實(shí)際橋面狀況下橋面板的疲勞壽命。
[Abstract]:With the rapid and steady growth of Chinese economy, the traffic volume of Chinese highway is increasing rapidly, and the problem of overloading is becoming more and more serious, which leads to a lot of fatigue problems of highway concrete bridges under vehicle load. The load-bearing capacity is mainly used as the control index of bridge structure safety. The durability index of bridge structure subjected to repeated loads is despised. Engineering practice shows that concrete deck slabs directly subjected to vehicle loads are most likely to suffer fatigue damage and failure under operating conditions. Therefore, this paper studies the fatigue life analysis method of concrete deck slab under random vehicle load. Based on the actual traffic volume observation and investigation data of a highway, the vehicle types on the highway are summarized and sorted, and the typical vehicle load library is established. The main parameters of traffic statistics, such as the probability distribution of vehicle model ratio, vehicle spacing and vehicle axle load, are determined, and the random traffic flow is simulated. The Lagrangian principle is used. The equations of motion of typical vehicles are constructed. The ANSYS finite element model is established and the modal analysis is carried out by selecting the common simply supported and continuously assembled prestressed reinforced concrete T-beam bridges. Based on the example, the types of vehicles are analyzed. The effect of vehicle speed and bridge deck irregularity on the dynamic impact effect of bridge structure under vehicle is compared with the calculated results of the code. The fatigue life prediction model and method of RC bridge slab based on continuous damage mechanics are established. The fatigue damage mechanism of reinforced concrete is studied. The main factors controlling the fatigue failure of bridge deck are analyzed. The characteristics and advantages and disadvantages of linear fatigue damage accumulation theory and nonlinear fatigue damage accumulation theory are compared. In this paper, the dynamic stress time history of the fatigue hot spot of the deck slab under random vehicle is calculated, the stress amplitude and mean stress are obtained by the rain flow counting method, and the fatigue life of the bridge deck is predicted by two different fatigue damage models. Finally, the fatigue life of the bridge deck is predicted and analyzed. The effects of traffic volume growth, overloading of vehicles and deterioration of deck condition on fatigue damage of bridge deck are studied. A traffic volume growth model is constructed by using grey model. The variation law of bridge deck stress amplitude under different traffic volume and the influence of changing traffic volume at fixed time node on the fatigue life of bridge deck slab are analyzed. According to the investigation data of overloading status of major highways in China, the influence of the change of traffic volume on the fatigue life of bridge deck slab is analyzed. The overloading ratio and overloading rate of each type of vehicle are pointed out, and the simulation method of random vehicle flow with overloaded vehicle is presented. The variation law of the stress amplitude of the deck slab under the action of the motorcade is analyzed. The effect of random vehicle flow with overloaded vehicles on the initial and middle life of the bridge structure is analyzed. According to the simulated bridge deck condition, the change of the stress amplitude of fatigue hot spot under the action of random vehicle and the prediction of the fatigue life of the bridge deck under the actual bridge deck condition are analyzed.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2016
【分類號(hào)】：U441.4
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本文編號(hào)：1568407