本文選題：梯形波紋腹板 + 疲勞評定��； 參考：《武漢科技大學(xué)》2016年碩士論文

【摘要】：梯形波紋腹板焊接梁是一種新型梁結(jié)構(gòu),由于其一系列優(yōu)越的力學(xué)特性,近年來得到較快的發(fā)展。梯形波紋腹板焊接梁大多采用焊接方式加工制造,疲勞性能對其工程實際應(yīng)用具有重要意義。本文從焊接結(jié)構(gòu)的疲勞理論出發(fā),研究了名義應(yīng)力法、熱點應(yīng)力法和等效結(jié)構(gòu)應(yīng)力法三種不同層次的疲勞評定方法,提出了等效結(jié)構(gòu)應(yīng)力法的應(yīng)用策略,系統(tǒng)分析了梯形波紋腹板焊接梁結(jié)構(gòu)的疲勞性能。主要研究工作如下:(1)開展了等效結(jié)構(gòu)應(yīng)力法的理論研究,給出了單元節(jié)點力的局部坐標(biāo)變換方式,實現(xiàn)了單元線載荷矩陣的數(shù)值求解方法;分析了焊接接頭局部基于SHELL單元的有限元模型構(gòu)造方式,得到了 T型焊接接頭進行等效結(jié)構(gòu)應(yīng)力法疲勞評定的建模方法;針對縱向受載的非承載型焊接結(jié)構(gòu),提出了一種縱向結(jié)構(gòu)應(yīng)力的構(gòu)造方法。(2)分析了大量梯形波紋腹板焊接梁的疲勞試驗結(jié)果,給出了彎曲作用下該結(jié)構(gòu)疲勞破壞的危險位置和疲勞行為;分別采用名義應(yīng)力法、熱點應(yīng)力法和等效結(jié)構(gòu)應(yīng)力法進行疲勞評定研究,結(jié)果表明:等效結(jié)構(gòu)應(yīng)力可比較準的預(yù)測裂紋萌生位置和估算疲勞壽命,建議采用等效結(jié)構(gòu)應(yīng)力作為梯形波紋腹板焊接梁的壽命評價控制參量。(3)以等效結(jié)構(gòu)應(yīng)力作為壽命控制參量,分析了三點彎曲和四點彎曲作用下梯形波紋腹板焊接梁的疲勞壽命,采用歸一化的思想消除跨距的影響,研究了腹板波紋數(shù)量對結(jié)構(gòu)疲勞性能的影響規(guī)律。提出:隨波紋數(shù)量的增加,結(jié)構(gòu)的疲勞強度逐漸增加;在三點彎曲循環(huán)載荷作用下,推薦腹板波紋數(shù)量取值為2n+1;在四點彎曲循環(huán)載荷作用下,推薦腹板波紋數(shù)量取值為2n+1或2n+0.5,且加載位置之間的波紋數(shù)量為整數(shù)。本文開展梯形波紋腹板焊接梁的疲勞性能研究,對梯形波紋腹板焊接梁的設(shè)計、生產(chǎn)與結(jié)構(gòu)裝配具有指導(dǎo)作用,對擴展其應(yīng)用領(lǐng)域具有重要意義。
[Abstract]:Trapezoidal corrugated web welded beam is a new type of beam structure, which has been developed rapidly in recent years because of its superior mechanical properties.Trapezoidal corrugated web welded beams are mostly manufactured by welding, and fatigue property is of great significance to its practical application.Based on fatigue theory of welded structures, three different fatigue assessment methods, nominal stress method, hot spot stress method and equivalent structural stress method, are studied in this paper. The application strategy of equivalent structural stress method is put forward.The fatigue behavior of trapezoidal corrugated web welded beam structure is analyzed systematically.The main research work is as follows: (1) the theoretical study of equivalent structural stress method is carried out, and the method of local coordinate transformation of element node force is given, and the numerical solution of element line load matrix is realized.The finite element model construction method based on SHELL element is analyzed, and the fatigue evaluation method of T-type welded joint by equivalent structural stress method is obtained.In this paper, a structural method of longitudinal structural stress is put forward. The fatigue test results of a large number of trapezoidal corrugated web welded beams are analyzed, and the dangerous position and fatigue behavior of fatigue failure of the structure under bending are given.The hot spot stress method and the equivalent structure stress method are used to evaluate fatigue. The results show that the equivalent structural stress can predict the crack initiation position and estimate the fatigue life.It is suggested that the equivalent structural stress be used as the life evaluation control parameter of trapezoidal corrugated web welded beam. The fatigue life of trapezoidal corrugated web welded beam under the action of three-point bending and four-point bending is analyzed with equivalent structural stress as the life control parameter.The influence of the number of web ripples on the fatigue properties of structures was studied by using the normalized idea to eliminate the influence of span.It is proposed that the fatigue strength of the structure increases gradually with the increase of the number of ripples, that the number of web ripples is recommended as 2n 1 under the action of three-point bending cyclic load, and that under the action of four-point bending cyclic load,The recommended number of web ripples is 2n 1 or 2n 0.5, and the number of ripples between loading positions is integer.In this paper, the fatigue performance of trapezoidal corrugated web welded beams is studied, which is of great significance to the design, production and structural assembly of trapezoidal corrugated web welded beams.
【學(xué)位授予單位】：武漢科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：TG405

【相似文獻】

相關(guān)期刊論文 前10條

1 益小蘇;;塑料熱板焊的過程分析研究[J];現(xiàn)代塑料加工應(yīng)用;1989年01期

2 張云;消除振動的簡單方法[J];鐵道機車車輛工人;1993年11期

3 ;管板焊金相試樣的制備[J];勞動保護;1985年05期

4 沈永祥，苑杰;具裂紋不同彈性材料有限板焊接的混合問題[J];寧夏大學(xué)學(xué)報(自然科學(xué)版);1996年01期

5 郭麗娟;;底架邊梁與側(cè)墻板焊縫不良質(zhì)量攻關(guān)[J];中國鐵路;2013年S1期

6 梁瑜;;厚壁板焊反應(yīng)器在加氫裝置上的應(yīng)用[J];河南化工;2009年11期

7 沈永祥，苑杰，周麗坤;含裂紋不同材料有限板焊接混合問題的簡化解法[J];松遼學(xué)刊(自然科學(xué)版);1996年04期

8 司鮮萍,武鴻謙;WH60A高強板焊接新材料新方法的研究及應(yīng)用[J];機械工人(熱加工);2004年03期

9 郭國林;吳永祥;顧sョ，

本文編號：1763238