考虑变间距隔板的起重机偏轨箱梁畸变特性研究

发布时间：2018-03-15 04:35

本文选题：起重机　切入点：横隔板　出处：《西南交通大学》2016年博士论文　论文类型：学位论文

【摘要】：随着我国现代物流产业规模的不断扩大,以大型化、轻量化为目标的起重机结构设计理念已广泛运用于生产实践过程中。单纯通过减小箱梁各板元厚度,实现整机结构轻量化,势必会降低箱梁各局部区格稳定性、增加箱梁各截面纵横向变形量,不利于生产安全。如在箱梁内部按一定间距焊接横隔板,则可有效提升各板元区格的局部稳定性,同时增加箱梁整体扭转刚度和抗畸变翘曲刚度,减小偏载作用下箱梁截面纵横向变形。合理布局横隔板间距,可优化箱梁截面应力应变分布特征、提高钢材利用率,以实现箱梁结构的轻量化设计。本文紧密围绕带变间距横隔板箱梁的截面畸变变形问题,构建了基于刚(柔)性隔板假设下的箱梁畸变分析模型,系统研究了隔板位置、数量及厚度等对箱梁截面畸变变形的影响规律。本文的研究内容主要有：(1)针对带隔板箱梁,将隔板与箱梁间作用力视为隔板厚度范围内的均布畸变力矩,分别基于隔板面内无限刚度假设和箱梁与隔板间剪切变形的协调性,提出了考虑截面畸变剪切变形的带刚(柔)性隔板简支梁(悬臂梁)畸变初参数法,继而推导出箱梁各截面畸变角和畸变翘曲函数的初参数解。对比不同隔板数量和厚度下箱梁各采样点处畸变角、畸变翘曲位移和应力初参数值和有限元仿真值,结果充分验证了刚(柔)性隔板假设下的简支梁(悬臂梁)畸变初参数法的正确性。(2)基于带柔性隔板简支梁(悬臂梁)畸变初参数法,分别围绕小车位于简支梁跨中、端部及悬臂梁端部等关键位置,展开轮压点截面处畸变角、畸变翘曲应力及畸变横向弯曲底角随箱梁高跨比、隔板数及厚度比参数化分析。结果表明：当小车位于简支梁跨中或端部时,增加隔板数量、截面高跨比及厚度比可有效抑制轮压点截面节点处畸变角、畸变翘曲应力及上下翼缘板横向弯曲变形。(3)以对称畸变载荷下轮压点处节点畸变翘曲位移及应力为目标展开三隔板简支梁的隔板位置优化分析。此优化问题是以跨中隔板局部剪切稳定性和承载板元局部弯剪组合稳定性为约束条件的连续型单变量优化问题。研究表明：不同对称外畸变力矩Md下,分别以小车轮压点处节点畸变翘曲应力、纵向畸变位移及两者组合为优化目标的最优隔板Ⅰ位于外畸变载荷作用截面处,此时跨中隔板及承载板元的局部屈曲临界载荷均为最大。(4)针对不等距对称三隔板简支梁,以小车轮压点处畸变翘曲函数的一(二)阶导数为等效目标,分析与上述三隔板等效的等距三隔板简支梁高度系数与宽度系数间关系,结果表明：基于最小二乘原理的两尺寸系数间存在线性相关性。继而,系统分析了不等距对称三隔板简支梁畸变翘曲刚度及框架刚度与原等距简支梁间非线性关系,研究表明：不等距对称三隔板简支梁相对原等距三隔板简支梁畸变翘曲刚度增大,畸变框架刚度减小。(5)分别以无(带)隔板简支箱梁为对象,通过FCS四通道液压伺服实验加载平台,直接对箱梁施加两对称集中畸变载荷,并借助百分表和应变仪对箱梁采样点处畸变位移和应力进行读取。对比畸变实验数据和初参数解,结果充分验证了以畸变翘曲函数为初始变量的四阶畸变初参数法的正确性和柔性隔板假设(变形协调性)的正确性。同时,鉴于加载实验过程中各实验环节的不确定性,测量节点处位移和应力存在一定范围的容许误差。误差主要来源于制造加工精度、安装精度和焊接后板件残余变形等。综上,本文整合了理论分析、有限元仿真和实验验证等三个部分,针对带横隔板箱梁截面畸变特性展开了系统研究。本文的研究丰富了箱梁结构设计中截面畸变知识体系,对完善箱梁结构轻量化设计理论体系具有重要意义。
[Abstract]:As China's modern logistics industry continues to expand the scale, to large-scale, crane structure lightweight design for the target has been widely used in the practice of production. Only by reducing the thickness of plate girder element, realize the whole lightweight structure, is bound to reduce the local stability of the grid box girder, box girder of the increase section of vertical and horizontal deformation, is not conducive to the production safety. As in the box girder according to a certain distance welding diaphragm, can effectively enhance the local stability of plate element grid, while increasing the box girder torsion stiffness and anti warping stiffness, reduce the partial load of box girder vertical and horizontal deformation. Reasonable the layout of diaphragm spacing, can optimize the box girder section stress and strain distribution, improve the utilization rate of steel, in order to achieve the lightweight design of box girder structure. This dissertation focuses on the deformation of cross section distortion with variable spacing diaphragm box girder, Based on rigid model partition (soft) under the assumption of box girder distortion analysis system of diaphragm position, number and thickness on the influence of box girder distortion. The main contents of this paper are: (1) the clapboard box girder, box girder and the partition between force as uniform distortion torque diaphragm thickness range, respectively based on the surface of the clapboard in the infinite stiffness assumption and box girder and diaphragm shear deformation coordination, considering the rigid band deformation of cross section distortion (soft) shear diaphragm Jian Zhiliang (cantilever) distortion of initial parameters, and then derive the initial parameter of box girder the cross-section distortion angle and distortion warping function solution. The thickness and quantity of different baffle box girder under different sampling point distortion angle distortion, warping displacement and stress of primary parameters and finite element simulation, the result proves that the stiffness (soft) diaphragm (under the assumption of Jian Zhiliang Cantilever) correct parameter method of distortion. At the beginning of (2) with flexible diaphragm beam (beam) distortion based on initial parameter method, respectively, around the car located in the end of the bridge, and the cantilever beam end key position, expanding wheel pressure point section distortion angle distortion, warping stress and transverse bending distortion the corner with the box girder height span ratio, the partition number and the thickness ratio of the parametric analysis. The results show that when the car is located in the bridge or end, increase the number of the partition plate, high cross section ratio and thickness ratio can inhibit the wheel pressure section of joint angle of distortion, distortion and warping stress on the flange lateral bending deformation. (3) analyze three position optimization partition partition beam as target to symmetry load tire pressure point node warping displacement and stress. This optimization problem is to cross diaphragm local shear stability and bearing plate element local bending shear combination The optimization problem of continuous stability for the constraints of the single variable. The research shows that different symmetrical distortion torque Md, with pressure on the wheels at the point of node distortion warping stress, vertical displacement and distortion combination for the optimal partition of the optimization target is located outside the distortion load section, the cross baffle and bearing local the buckling load of the plate element are the biggest. (4) for non equidistant symmetric three partition beam, with car wheel pressure at the point of distortion warping function (two) is a derivative of equivalent target, analysis and the three equivalent equidistant partition three partition beam height coefficient and the width coefficient of the relationship between the results show that there is the linear correlation coefficient between the two dimensions based on the principle of least squares. Then, analyzed the non equidistant symmetric three partition beam distortion warping stiffness and stiffness of the frame with the original nonlinear beam offset The relationship, research shows that non equidistant symmetric three partition beam relative to the original three equidistant partition beam warping stiffness increases, the distortion of frame stiffness decreases. (5) with no (belt) plate simply supported box girder as the object, through the FCS four channel hydraulic servo loading platform, directly applying the two symmetry of the box girder concentrated load and distortion, with the aid of a dial gauge and strain gauge on the box girder sampling point distortion displacement and the stress of reading. Comparing the experimental data distortion and the initial parameter solution, verified by the distortion warping function of four order distortion of the initial variables initial parameter method and the correctness of the flexible diaphragm hypothesis (deformation coordination) right. At the same time, in view of the experimental aspects during the loading process of uncertainty measurement error allowable node displacement and stress in certain range. The main error sources for manufacturing and processing precision, accuracy and installation after welding In the residual deformation. In conclusion, this paper integrates the theoretical analysis, the three part of the finite element simulation and experimental verification, for diaphragm of box girder distortion characteristics have been studied in this paper. This study enriches the box beam structure design of cross section distortion knowledge system, and has important significance to perfect the theory of box girder structure lightweight design.

【学位授予单位】：西南交通大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TH21

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