發(fā)布時(shí)間：2018-04-29 21:46

  本文選題：公路鋼橋 + 疲勞設(shè)計(jì)��； 參考：《長(zhǎng)安大學(xué)》2014年碩士論文

【摘要】：鋼結(jié)構(gòu)橋梁雖然具有自重輕、跨徑大等優(yōu)點(diǎn)，但是由于長(zhǎng)期承受車輛荷載循環(huán)作用，加上其自身焊接連接、截面突變、應(yīng)力集中等因素容易引發(fā)疲勞裂紋，嚴(yán)重時(shí)會(huì)發(fā)生疲勞斷裂破壞。我國(guó)現(xiàn)行的公路橋涵鋼結(jié)構(gòu)及木結(jié)構(gòu)設(shè)計(jì)規(guī)范中疲勞設(shè)計(jì)部分相對(duì)落后，對(duì)公路鋼結(jié)構(gòu)橋梁疲勞問題的特點(diǎn)認(rèn)知不足，已經(jīng)不能滿足我國(guó)公路鋼橋設(shè)計(jì)的需要；而我國(guó)公路鋼結(jié)構(gòu)橋梁設(shè)計(jì)規(guī)范還處在修訂狀態(tài)，因此針對(duì)這一現(xiàn)狀開展對(duì)公路鋼橋抗疲勞設(shè)計(jì)方法的研究很有必要。具體而言，本文主要做了以下工作： 1）從抗疲勞設(shè)計(jì)計(jì)算準(zhǔn)則和計(jì)算公式、疲勞細(xì)節(jié)分類和疲勞荷載三個(gè)主要方面對(duì)國(guó)外相對(duì)成熟的AASHTO、BS5400、Eurocode、日本規(guī)范，以及我國(guó)鋼結(jié)構(gòu)設(shè)計(jì)規(guī)范、鐵路鋼橋規(guī)范和公路橋涵鋼結(jié)構(gòu)及木結(jié)構(gòu)設(shè)計(jì)規(guī)范進(jìn)行對(duì)比研究分析。 通過對(duì)AASHTO基于無限壽命法和安全壽命法的兩種抗疲勞設(shè)計(jì)準(zhǔn)則和計(jì)算公式、BS5400三級(jí)循序漸進(jìn)且自成體系的抗疲勞設(shè)計(jì)準(zhǔn)則和計(jì)算公式、Eurocode基于絕對(duì)安全設(shè)計(jì)和損傷容限設(shè)計(jì)的三等級(jí)設(shè)計(jì)（無限壽命設(shè)計(jì)、等效損傷設(shè)計(jì)和損傷累積設(shè)計(jì)）的計(jì)算準(zhǔn)則和計(jì)算公式、日本規(guī)范基于無限壽命法和安全壽命法的簡(jiǎn)便評(píng)定和損傷累積評(píng)定計(jì)算準(zhǔn)則和計(jì)算公式的研究，基于我國(guó)規(guī)范中的計(jì)算準(zhǔn)則和公式，指出其中有待更新和可以沿用的部分，并給出適用于我國(guó)公路橋梁鋼結(jié)構(gòu)疲勞設(shè)計(jì)計(jì)算公式。 對(duì)國(guó)內(nèi)外規(guī)范疲勞細(xì)節(jié)的類別、等級(jí)強(qiáng)度與S-N曲線特征進(jìn)行對(duì)比分析，通過對(duì)國(guó)內(nèi)外疲勞細(xì)節(jié)的劃分原則，以及我國(guó)鐵路鋼橋規(guī)范中細(xì)節(jié)分類與國(guó)外規(guī)范之間的差別進(jìn)行詳細(xì)研究，指出我國(guó)公路鋼橋規(guī)范疲勞細(xì)節(jié)劃分時(shí)應(yīng)采用的原則和值得注意的問題，并指出我國(guó)需要通過增加疲勞試驗(yàn)或開展新的疲勞試驗(yàn)來確定強(qiáng)度等級(jí)大小的疲勞細(xì)節(jié)，為我國(guó)公路鋼結(jié)構(gòu)橋梁中疲勞細(xì)節(jié)分類提供參考和建議。 通過對(duì)AASHTO、BS5400、Eurocode和日本規(guī)范中疲勞荷載進(jìn)行研究分析，給出了疲勞荷載的主要形式。簡(jiǎn)述了標(biāo)準(zhǔn)疲勞車模型的推導(dǎo)方法，并以簡(jiǎn)支梁橋?yàn)槔�，采用有限元程序ANSYS計(jì)算分析了不同跨徑下AASHTO、Eurocode和BS5400標(biāo)準(zhǔn)疲勞車、日本T荷載，以及我國(guó)公路-Ⅰ級(jí)、公路-Ⅱ級(jí)和城-A級(jí)、城-B活載車輛對(duì)簡(jiǎn)支梁跨中截面造成的彎矩幅大小，以及不同軸數(shù)的車輛造成的應(yīng)力循環(huán)次數(shù)，得到我國(guó)已有車輛模型與國(guó)外的標(biāo)準(zhǔn)疲勞車輛之間的差異程度，為我國(guó)公路鋼橋制定疲勞荷載提供參考。 2）以大榭第二大橋?yàn)楣こ瘫尘�，依�?jù)AASHTO、Eurocode和日本規(guī)范，采用有限元程序ANSYS對(duì)該橋正交異性鋼橋面板的典型疲勞細(xì)節(jié)進(jìn)行疲勞強(qiáng)度驗(yàn)算。通過對(duì)計(jì)算結(jié)果進(jìn)行分析，，并從抗疲勞設(shè)計(jì)準(zhǔn)則、疲勞細(xì)節(jié)分類和疲勞荷載三個(gè)方面綜合考慮，得出最適合我國(guó)公路鋼橋正交異性鋼橋面板抗疲勞設(shè)計(jì)的規(guī)范，為我國(guó)公路鋼橋正交異性鋼橋面的抗疲勞設(shè)計(jì)提供參考。
[Abstract]:Although the steel structure bridge has the advantages of light weight and long span, it is easy to cause fatigue crack due to the long-term bearing of vehicle load cycle, the welding connection, the sudden change of cross section, the stress concentration and so on. Fatigue fracture will occur when it is serious. The fatigue design of highway bridge and culvert steel structure and wood structure design code is relatively backward in our country, and the characteristics of highway steel bridge fatigue problem are not well understood, which can not meet the needs of highway steel bridge design in our country. However, the design code of highway steel bridge in China is still in the state of revision, so it is necessary to study the fatigue design method of highway steel bridge in view of this situation. Specifically, the main work of this paper is as follows: 1) from the three main aspects of fatigue design calculation criterion and formula, fatigue detail classification and fatigue load, the relative mature AASHTOU BS5400 Eurocodecode, Japanese code, and steel structure design code of our country are discussed. The code of railway steel bridge and the design code of highway bridge and culvert steel structure and wood structure are compared and analyzed. This paper introduces two kinds of anti-fatigue design criteria and calculation formula of AASHTO based on infinite life method and safe life method. BS5400 three-stage, step-by-step and self-made fatigue design criterion and calculation formula are given. Eurocode is based on absolute safety design and damage capacity. Limited design three-level design (infinite life design, The Japanese code is based on the simple assessment of infinite life method and the safe life method and the study of damage accumulation assessment criterion and formula. Based on the calculation criteria and formulas in the code of our country, this paper points out the parts that need to be renewed and can be used, and gives the calculation formulas suitable for the fatigue design of steel structures of highway bridges in China. The classification, grade strength and S-N curve characteristics of fatigue details are compared and analyzed, and the classification principles of fatigue details at home and abroad are discussed. The differences between the detail classification of railway steel bridge codes in China and the foreign codes are studied in detail. The principles and problems to be paid attention to in the division of fatigue details of the code for highway steel bridges in China are pointed out. It is pointed out that fatigue details of strength grade should be determined by increasing fatigue test or carrying out new fatigue test in our country, which provides reference and suggestion for classification of fatigue details in highway steel structure bridges in China. Based on the analysis of fatigue loads in AASHTO BS5400 Eurocode and Japanese codes, the main forms of fatigue loads are given. In this paper, the derivation method of standard fatigue vehicle model is briefly introduced. Taking simply supported beam bridge as an example, the calculation and analysis of AASHTO Eurocode and BS5400 standard fatigue vehicle, T load in Japan, and highway grade I in China under different spans are carried out by using finite element program ANSYS. The magnitude of bending moment caused by the highway-class 鈪

本文編號(hào)：1821705