【摘要】：平頭式塔式起重機(jī)在安裝和使用過程中的優(yōu)勢(shì)越來(lái)越明顯，但由于其發(fā)展的歷史不是很長(zhǎng)，工況載荷對(duì)其結(jié)構(gòu)因素的影響還沒有得到充分的實(shí)踐數(shù)據(jù)驗(yàn)證。目前對(duì)于平頭式塔式起重機(jī)的研究還主要是通過類比的方法來(lái)進(jìn)行結(jié)構(gòu)強(qiáng)度及穩(wěn)定性設(shè)計(jì)計(jì)算，而對(duì)于利用疲勞特性方法并綜合載荷、材料、焊接結(jié)構(gòu)等許多不確定因素的影響來(lái)分析其結(jié)構(gòu)壽命考慮較少。 本文以QTZ100平頭式塔式起重機(jī)起重臂作為研究對(duì)象，，利用疲勞理論方法和有限元數(shù)值方法得出了起重臂弦桿與腹桿焊接處的疲勞壽命及允許的初始裂紋長(zhǎng)度，并結(jié)合實(shí)驗(yàn)進(jìn)行了驗(yàn)證。 本文的主要內(nèi)容簡(jiǎn)述如下： （1）對(duì)QTZ100平頭式塔式起重機(jī)起重臂弦桿與腹桿焊接處進(jìn)行理論和數(shù)值計(jì)算，得出弦桿與腹桿焊接處的應(yīng)力值,并通過對(duì)載荷譜的研究得出應(yīng)力幅值。 （2）綜合應(yīng)力幅值和《起重機(jī)設(shè)計(jì)規(guī)范》（GB/T3811-2008）對(duì)于塔機(jī)的設(shè)計(jì)壽命要求并以經(jīng)典疲勞理論與高周疲勞損傷理論為基礎(chǔ)得出兩種理論下允許的初始裂紋長(zhǎng)度。 （3）將QTZ100平頭式塔式起重機(jī)起重臂弦桿與腹桿焊接結(jié)構(gòu)處進(jìn)行簡(jiǎn)化后試制出疲勞拉伸試樣，應(yīng)用疲勞試驗(yàn)機(jī)進(jìn)行疲勞特性實(shí)驗(yàn)，并對(duì)其實(shí)驗(yàn)結(jié)果進(jìn)行了分析。 （4）對(duì)QTZ100平頭式塔式起重機(jī)起重臂焊接結(jié)構(gòu)處進(jìn)行有限元建模分析，將得出的應(yīng)力應(yīng)變場(chǎng)及裂紋擴(kuò)展形態(tài)與理論及實(shí)驗(yàn)結(jié)果進(jìn)行了對(duì)比。 本文著重對(duì)焊縫的裂紋擴(kuò)展壽命及擴(kuò)展形態(tài)進(jìn)行了研究，得出了在存在不同焊縫裂紋時(shí)的疲勞壽命和在設(shè)計(jì)壽命基礎(chǔ)上允許的初始裂紋長(zhǎng)度，為塔式起重機(jī)起重臂的疲勞壽命預(yù)測(cè)提供了新的研究方法，同時(shí)也為塔式起重機(jī)起重臂的疲勞壽命設(shè)計(jì)提供理論依據(jù)。
[Abstract]:The advantages of flat head tower crane in installation and use are more and more obvious, but the influence of load on its structure has not been fully verified by practical data due to the fact that the history of its development is not very long. At present, the research of flat head tower crane is mainly carried out by analogy method to design and calculate the structural strength and stability, but for the use of fatigue characteristic method and comprehensive load, material, The influence of many uncertain factors, such as welding structure, on structural life is less considered. In this paper, the fatigue life and the allowable initial crack length of the joint between the chord and the web are obtained by using the fatigue theory method and the finite element numerical method, taking the lifting arm of the QTZ100 flat head tower crane as the research object. The experimental results are verified. The main contents of this paper are summarized as follows: (1) the theoretical and numerical calculation of the joint between the chord and the web of the QTZ100 flat head tower crane is carried out, and the stress values of the joint between the chord and the web are obtained. The stress amplitude is obtained by studying the load spectrum. (2) combining the stress amplitude and the Crane Design Code (GB/T3811-2008) for the design life of the tower crane, and based on the classical fatigue theory and the high cycle fatigue damage theory, the allowable initial crack length is obtained. (3) the fatigue tensile specimen was made by simplifying the welding structure between the hoist chord and the web rod of the QTZ100 flat head tower crane, and the fatigue characteristic experiment was carried out by using the fatigue testing machine, and the experimental results were analyzed. (4) the finite element modeling and analysis of the welded structure of the lifting jib of QTZ100 flat head tower crane are carried out, and the stress and strain field and crack propagation are compared with the theoretical and experimental results. In this paper, the fatigue life and the initial crack length allowed on the basis of the design life are obtained by studying the crack propagation life and the propagation morphology of the weld seam, and the fatigue life and the initial crack length of the weld are obtained when there are different weld cracks. It provides a new research method for predicting the fatigue life of the tower crane boom, and also provides a theoretical basis for the design of the fatigue life of the tower crane boom.
【學(xué)位授予單位】：湘潭大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2012
【分類號(hào)】：TH213.3

【參考文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前1條

1 楊華平;QTZ100平頭式塔式起重機(jī)結(jié)構(gòu)安全性研究[D];湘潭大學(xué);2011年

本文編號(hào)：2421831