本文選題：失效樹 + 承載能力�。� 參考：《中國鐵道科學研究院》2015年博士論文

【摘要】：近年來我國經(jīng)濟快速發(fā)展,鐵路橋梁承受著越來越繁重的交通運能,通過增大列車軸重來增加運能、提高運輸效率已成為目前鐵路的發(fā)展趨勢之一。而且,我國鐵路貨車制造技術(shù)已經(jīng)接近或達到了世界先進水平,完全具備生產(chǎn)大軸重貨車的能力。在這種情況下,我國既有鐵路鋼橋是否具備開行重載運輸?shù)臈l件,即在承載能力和疲勞性能等方面能否滿足安全性要求,需要展開深入研究。另外,隨著我國橋梁建造技術(shù)的不斷進步,鋼橋的跨度不斷增大,結(jié)構(gòu)構(gòu)造在不斷創(chuàng)新,大量新型構(gòu)造細節(jié)也應(yīng)運而生,新型構(gòu)造細節(jié)的疲勞性能能否滿足重載運輸?shù)囊?也需要加以關(guān)注。論文結(jié)合既有鐵路鋼橋開行重載列車后需要亟待解決的問題,從承載能力、疲勞加載特征以及疲勞壽命評估等方面出發(fā),通過計算分析、關(guān)鍵構(gòu)造細節(jié)疲勞試驗等方式,從如下幾方面展開了研究。采用失效樹理論的最小荷載增量法,選擇典型鋼桁梁(64m下承式單、雙線鋼桁梁),對其在設(shè)計荷載、27噸、30噸軸重重載列車作用下的極限承載力進行計算分析。研究得到了在不同荷載加載條件下,鋼桁梁的失效模式、失效控制桿件以及極限承載力,掌握了鋼桁梁的安全儲備。依據(jù)最不利換算均布荷載效應(yīng),通過挖掘動力系數(shù)的儲備,對按照中-活載設(shè)計的橋梁對27噸、30噸軸重重載列車的適應(yīng)性進行計算分析,得到了重載列車的適應(yīng)跨度(影響線長度)范圍。對不同疲勞壽命評估方法進行總結(jié)分析,包括基于S-N曲線的疲勞壽命評估方法和基于線彈性斷裂力學的疲勞壽命評估方法,其中基于S-N曲線的疲勞壽命評估方法包括兩種,一種是傳統(tǒng)確定性的疲勞壽命評估法,一種是基于可靠性理論的疲勞壽命評估法。采用上述幾種疲勞評估方法,選擇典型鋼桁梁(64m下承式單、雙線鋼桁梁),評估其運營30噸軸重重載列車后的疲勞壽命,得到了不同桿件的剩余疲勞壽命,及需要進行加固補強的桿件。對實橋加載波形進行研究分析,驗證試驗室加載波形與實橋加載波形的區(qū)別。選擇鐵路鋼橋幾種關(guān)鍵構(gòu)造細節(jié),開展了矩形波(梯形波)和正弦波兩種波形加載條件下的疲勞試驗研究。研究不同加載波形對于構(gòu)造細節(jié)疲勞性能的影響程度,判斷極端重載運輸條件下,構(gòu)造細節(jié)的疲勞性能是否有所改變,以及在進行疲勞檢算時,其容許值是否需要折減和折減系數(shù)的取值。對各類新型鋼橋構(gòu)造細節(jié)進行分類總結(jié),分別對主桁桿件構(gòu)造細節(jié)、橋面系構(gòu)造細節(jié)、主桁與橋面系連接等三大類17種構(gòu)造細節(jié)進行歸類分析,研究不同類型構(gòu)造細節(jié)的重載適應(yīng)性,對于疲勞強度不能滿足重載運輸條件的構(gòu)造,提出相應(yīng)的改進措施建議。
[Abstract]:In recent years, the rapid economic development of our country, the railway bridges bear more and more heavy traffic energy. By increasing the axle weight of the train, increasing the transport energy and improving the transport efficiency have become one of the developing trends of the railway. Moreover, the manufacturing technology of railway freight cars in our country is close to or reached the advanced level in the world, and it is fully equipped with large axle heavy cargo. In this case, in this case, whether or not the railway steel bridge has the condition of carrying heavy load, that is, whether it can meet the safety requirements in bearing capacity and fatigue performance, it is necessary to carry out a thorough study. In addition, with the continuous progress of the bridge construction technology in China, the span of the steel bridge is increasing, and the structure and structure are constantly innovating. A large number of new structural details have come into being. Can the fatigue performance of the new structural details meet the requirements of heavy haul transportation, and it also needs to be paid attention to. The paper combines the problems that need to be solved after the railway steel bridge opens the heavy haul train, which is based on the bearing capacity, fatigue loading characteristics and fatigue life assessment. Analysis of the key structural details fatigue test and other ways, from the following aspects, the minimum load increment method of failure tree theory is adopted to select the typical steel truss beam (64M down bearing single, double wire steel truss) to calculate and analyze its ultimate bearing capacity under the action of design load, 27 ton, 30 ton axle heavy load train. Under the same load loading condition, the failure mode, the failure control rod and the ultimate bearing capacity of the steel truss girder have mastered the safety reserve of the steel truss. According to the most unfavorable conversion average load effect, through the excavation of the dynamic coefficient, the adaptability of the 27 ton and 30 ton axle heavy load train according to the bridge of medium live load design is calculated and analyzed. According to the adaptation span (influence line length) range of the heavy load train, the different fatigue life assessment methods are summarized and analyzed, including the fatigue life assessment method based on the S-N curve and the fatigue life assessment method based on the linear elastic fracture mechanics. The fatigue life assessment method based on the S-N curve includes two kinds, one is the traditional determination. The fatigue life assessment method, one is based on the fatigue life assessment method based on the reliability theory, chooses the typical steel truss beam (64M down bearing single, double wire steel truss) to evaluate the fatigue life after the 30 ton axle heavy load train, and obtains the residual fatigue life of different rods, and the need to reinforce and supplement the fatigue life. This paper studies and analyzes the load waveform of the real bridge, and verifies the difference between the loading waveform of the test room and the actual bridge loading waveform. Select several key structural details of the railway steel bridge and carry out the fatigue test under the two loading conditions of the rectangular wave (trapezoid wave) and the sine wave. The different loading waveforms are studied for the structural details fatigue performance. The degree of influence is to determine whether the fatigue performance of the structural details is changed or not, and whether the allowable values of the structural details should be reduced and the reduction coefficient values are needed in the calculation of fatigue. The structural details of the new type steel bridges are classified, the details of the structural details of the bridge deck system, the main truss and the main truss are made respectively. 17 types of structural details are classified and analyzed in three major categories, such as bridge deck connection. The heavy load adaptability of different types of structural details is studied. Suggestions for improvement measures are proposed for the failure of fatigue strength to meet the heavy load transport conditions.
【學位授予單位】：中國鐵道科學研究院
【學位級別】：博士
【學位授予年份】：2015
【分類號】：U446

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本文編號：2107932