本文選題：冷彎薄壁型鋼 + 穩(wěn)定性能�。� 參考：《沈陽建筑大學》2014年碩士論文

【摘要】：冷彎薄壁型鋼構件的穩(wěn)定問題一直是鋼結(jié)構科研工作者和規(guī)范編制人員工作中的重點。新型截面形式的出現(xiàn)以及超薄、高強鋼材的應用,帶來了許多新的穩(wěn)定問題。目前,對冷彎薄壁型鋼受壓構件的穩(wěn)定問題的研究和成果大多集中在截面形式簡單的槽鋼和卷邊槽鋼類構件,對于設置加勁肋和復雜卷邊等復雜截面形式的研究成果相對較少�，F(xiàn)有的關于復雜截面形式的研究大都是針對軸心受壓構件,對于偏心受壓構件的研究還很少見。另外,現(xiàn)有的有效截面計算方法已經(jīng)不足以滿足各種新型截面形式構件的計算。因此,國外學者提出直接強度計算方法來代替有效截面法計算冷彎薄壁型鋼構件的承載力。目前,各國規(guī)范中采用的直接強度計算方法只適用于計算軸壓狀態(tài)或純彎狀態(tài)下的槽鋼和卷邊槽鋼構件,關于偏壓狀態(tài)下的槽鋼和卷邊槽鋼構件的直接強度計算方法還沒有明確的計算公式。針對這些問題,本文分別對復雜卷邊槽鋼、腹板中間∑形加勁復雜卷邊槽鋼、腹板中間V形加勁復雜卷邊槽鋼三種截面形式,共計12根簡支偏心受壓構件進行了承載力試驗。研究了構件的極限承載力、破壞模式及變形等特性。試驗結(jié)果表明,腹板加勁有效地減小了板件寬厚比,大幅度提高向腹板一側(cè)偏心受壓構件的極限承載力,使畸變屈曲代替局部屈曲起主要控制作用,但對向卷邊一側(cè)偏心受壓構件的極限承載力影響很小采用非線性有限元軟件ANSYS對試驗進行了有限元模擬,驗證了模擬的有效性。在此基礎上,對3種不同截面形式共計302個算例的復雜卷邊槽鋼偏心受壓構件穩(wěn)定性能進行了模擬分析。結(jié)果表明：腹板加勁可以提高向腹板一側(cè)偏心受壓構件的極限承載力和鋼材利用率,其中∑形加勁要優(yōu)于V形加勁。有效形心偏移對偏壓構件承載力的影響不可忽視,構件極限承載力最大值出現(xiàn)在荷載作用于有效形心位置處時。板厚變化對腹板中間V形加勁復雜卷邊槽鋼影響顯著。以我國現(xiàn)有的偏心受壓構件的有效截面計算方法為基礎,結(jié)合軸心受壓構件和純彎構件的直接強度法,提出了偏心受壓構件的直接強度計算方法。通過對125個構件的已有試驗和103個算例模擬結(jié)果進行驗算確定,本文提出公式適用于計算荷載作用在對稱軸平面內(nèi)的普通卷邊槽鋼和復雜卷邊槽鋼偏心受壓構件的承載力。
[Abstract]:The stability of cold-formed thin-walled steel members has always been the focus of scientific research workers and code compilers of steel structures. The appearance of new cross-section and the application of super-thin and high-strength steel have brought many new stability problems. At present, most of the researches and achievements on the stability of cold-formed thin-walled steel compression members are focused on channel steel and crimped channel steel members with simple section form, but the research results on the complicated section form such as stiffening rib and complicated edge are relatively few. Most of the existing researches on complex cross-section are aimed at axial compression members, but the research on eccentric compression members is rare. In addition, the existing effective section calculation methods are not enough to meet the calculation of various new cross-section members. Therefore, foreign scholars put forward direct strength calculation method instead of effective section method to calculate the bearing capacity of cold-formed thin-walled steel members. At present, the direct strength calculation methods used in national codes are only suitable for calculating channel steel and crimped channel steel members under axial compression or pure bending. There is no clear formula for calculating the direct strength of channel steel and crimped channel steel members under the state of bias. Aiming at these problems, the bearing capacity of 12 simply supported eccentrically compressed members were tested in this paper, including complex crimped channel steel, sigma-shaped stiffened channel steel with complex edge, and V-shaped stiffened and complicated crimped channel steel with V-shape in the middle of web plate. The ultimate bearing capacity, failure mode and deformation of the members are studied. The test results show that the stiffening of web can effectively reduce the width to thickness ratio of the plate, greatly increase the ultimate bearing capacity of eccentric compression members on one side of the web, and make the distortion buckling play a major role in controlling the local buckling instead of the local buckling. But the ultimate bearing capacity of eccentric compression members on one side of the crimping edge is very small. The nonlinear finite element software ANSYS is used to simulate the finite element test, and the validity of the simulation is verified. On the basis of this, the stability performance of eccentric compression members of complicated crimped channel steel with 302 different cross section forms is simulated and analyzed. The results show that the ultimate bearing capacity and steel utilization ratio of eccentric compression members on one side of the web can be improved by stiffening the web, in which 鈭，

本文編號：1877559