【作者】 丛欣建；

【导师】 于天来；

【作者基本信息】 东北林业大学 ， 道路与铁道工程， 2005， 硕士

【摘要】 箱形截面梁是目前桥梁中广泛采用的一种截面形式,具有优良的结构受力性能,但箱梁的约束扭转分析则较为复杂,本文介绍了不考虑断面变形的箱梁扭转理论和考虑断面畸变的符拉索夫广义变分法,论述了用有限元法计算断面有、无畸变的薄壁杆的理论,并以此为基础编制了相应的有限元程序,该程序对于等截面薄壁直杆的扭转分析非常适用,且具有较高的计算精度。 对于复杂的变截面连续箱梁的扭转分析,则需借助通用有限元程序对结构进行空间分析,本文以齐齐哈尔嫩江公路大桥模型试验为研究对象,采用通用有限元程序ANSYS对试验模型进行仿真分析,将模型在不同荷载工况作用下扭转畸变效应的理论计算值与试验值进行了比较分析,取得了较为理想的结果,表明用ANSYS中的SHELL63壳单元对复杂的大跨度变截面连续箱梁进行空间分析是可行性的,并以此为基础重点讨论了横隔板的密度及厚度对变截面连续箱梁在偏心荷载作用下所产生畸变效应的影响程度。通过计算分析认为,横隔板可以显著减小变截面连续箱梁的畸变效应,特别是在跨中断面设置横隔板,能有效的减小跨中截面附近的畸变应力,而在4等分截面、6等分截面设置横隔板对截面畸变效应的约束作用有一定减小。最后,变截面连续箱梁在横隔板间距一定的情况下,将中间横隔板厚度的变化对畸变效应的影响程度做了分析,计算结果表明,当横隔板具有一定的刚度时,中间横隔板厚度的变化对畸变效应的影响较小。本文分析所得的结论对变截面连续箱梁的设计和施工有一定指导意义。更多还原

【Abstract】 The box girder is a kind of sectional form adopted extensively in the bridge at present, there is fine structure that receives strength performance , but thin wall structure torsion analysing comparatively complicated, this paper introduced the box girder torsion theory of nothing section distortion and consider section distortion bend over broad sense calculus of V.Z.Vlasov. it also introduced the thin wall finite element theory with distorted and undistorted section, and work out corresponding finite element program, this program is very applicable to the torsional analysis of the turn simple one section thin wall straight pole , have the higher precision of calculation.Turn as to the torsion analysis of complicated continuous beam, it need the space analysis with the general finite element program. This paper regards Nenjiang highway bridge model test of Qiqihar as the research object, adopt finite element program ANSYS to emulate the test model, at the different load operation ,it compare the calculate value to test value of the shear-lag effect and torsion effect, have made the comparatively ideal result, have proved to complicated turning the feasibility of analysing the space into the continuous case roof beam of section with shell element SHELL63 in ANSYS. Based on this, it discussed influence degree of horizontal density of diaphragm to the distortion of the continuous girder bridge at the different load, think through computational analysis , the horizontal diaphragm can reduce the distortion effect of the continuous girder bridge, set up the diaphragm nearby greater distortion stress in the reduction that it can be effective supports the place and steps specially while supporting the place and stepping, but set up a fairly large number of horizontal diaphragm, it is very difficult to reduce the continuous distortion effect to neglected degree, so must consider the influence of distortion when we analyse the continuous girder bridge. Finally, at the certain diaphragm idensity, have made brief analysis in impact on distortion effect of change of the diaphragm thickness in the middle, the change of the horizontal thickness of diaphragm has a little effect on distortion effect, this conclusion is unanimous with Japanese scholar. This paper’ conclusion would be help to the design and construction of the continuous girder bridge.更多还原