网架焊接空心球节点的应力分析

机械设计制造及其自动化论文，论文编号:JX1018  论文字数:13385.页数:35

 摘  要
 随着网架结构的推广，焊接空心球节点作为这一种比较合理的节点形式越来越多的在工程中得到应用。虽然焊接空心球节点在静力性能方面已有广泛的研究，但其疲劳问题却研究甚少，应力集中是构建及节点发生疲劳破坏的重要因素之一。焊接空心球节点受拉时，钢管和球节点连接区应力集中严重。三向拉应力状态愈严重，钢材愈与脆断，所以该区域很可能最先开裂而导致焊接空心球节点失去承载能力。脆性破坏是钢结构的一种特殊问题，传统的强度计算解决不了这一问题。本文利用ANSYS有限元分析软件，以网架焊接空心球连接节点和半圆形楼为研究对象，以非线性有限元为理论基础，ANSYS为分析工具，采用SOLID95实体单元模拟节点的受力分布，分析了网架焊接空心球连接节点和工程体在单轴拉伸作用下的应力集中。
 关键词：网架  焊接空心球节点  有限元分析  应力集中  疲劳

ABSTRACT
  With the promotion of grid structure, as a more reasonable form of joints,welded hollow spherical joints has been applied more and more in engineering. Although the welded holloe spherical joints has been widely studied in the static performance, the fatigue problem has little reseaech,stress concentration is one of the important factors that cause fatigue undermine of the component and joints. When hollow spherical joints is in stste of pulling, there is serious tensile stress concentration on pontes between circular steel bar and ball node. There are more serious of the tensile stress, more easily to occur ductile-brittle fracture, Therefore this region is very possible to crack first causes the welding hollow ball node to lose the bearing capacity. Ductile-brittle fracture of steel structures are a special problem, the traditional strength calculation can not solve this problem.This article uses the ANSYS finite element analysis software, taking wire table welding hollow ball connection node and semicircle building as object of study , basing on the theory of nonlinear finite element, taking ANSYS as analysis tools, using force distribution of solid element simulation nodes SOLID95 , analyzing the grid connections and welded hollow spherical body works under uniaxial tensile stress concentration.
 
 Key words: grid structure  welded hollow spherical joints  finite element analysis  stress concentration  fatigue

目 录
中文摘要 i
英文摘要 ii
目 录 iii
第一章 绪 论 1
1.1 研究动机与目的 1
1.2 国内外研究现状 1
1.3 研究背景与意义 1
1.4 研究方法与主要内容 2
第二章 网架焊接空心球节点的应力集中分析 3
2.1 应力集中问题概述 3
2.1.1 概述 3
2.1.2 应力集中对焊接结构疲劳性能的影响 4
2.1.3 焊接空心球节点网架存在的问题 6
2.2 架焊接空心球节点的理论分析 8
2.2.1 分析工具ANSYS简介 8
2.2.2 分析模型选取原则 10
2.2.3分析模型的建立 13
2.2.4 焊接空心球应力集中计算结果 16
第三章 半圆形楼的应力集中分析 24
3.1 分析模型的建立 24
3.2 半圆形楼的应力集中计算结果 24
第四章 结 论 29
参考文献 30
致 谢 32