摘要
缺陷存在于任何建筑结构当中,在役结构由于初始缺陷的存在和服役过程中不可预知情况的影响,结构损伤也是不可预知的。在实际工程中大跨空间结构因承受荷载的随机性强,且材料特性及施工误差等原因会产生各种初始随机缺陷,因此结构的几何特性、损伤演变机制和承载能力往往会不符合设计的理想化模型,也会使结构偏于不安全,最终导致损伤出现。考虑弹性模量、泊松比、杆件截面面积等初始缺陷因素,采用基于随机有限元的蒙特卡罗概率设计方法产生结构的随机缺陷;假定结构随机缺陷的统计特征服从正态分布,采用ANSYS的PDS技术结合结构模态分析确定结构响应的敏感参数,生成符合正态分布的具有随机缺陷的网架结构模型;最后采用基于曲率模态差和小波变换相结合的损伤识别方法对给定的正放四角锥网架结构杆单元损伤进行识别,并将识别结果与理想结构的识别结果对比,得出随机缺陷对正放四角锥网架结构杆单元损伤识别的影响。
Defects exist in any structure.Structural damage of in-service structure is unpredictable because of initial defects and other unpredictable situations.In actual engineering projects of long-span space structures,material characteristics and construction errors will cause various initial random defects because of the strong randomicity.As a result,the ideal design models are usually not suitable for the geometrical characteristics,damage evolutionary mechanism and bearing capacity of the structure,which may lead to an unsafe structure and eventually cause damage.This paper presented the random defects of structure by Monte Carlo method considering elasticity modulus,poisson＇s ratio,section area of member and so on.Assuming the statistical characteristic of random defects of the structure is normal distribution,the sensitive parameter of structural response was determined by PDS and structural mode analysis,a square pyramid space grid models with random defects was obtained.Finally,based on the curvature mode difference and wavelet transform,the damage of the members of square pyramid space grid structure was identified.The influence of the initial defects on the damage detection of square pyramid space grid structure was obtained by comparing the detection results of the proposed structure and ideal structure.
出处
《钢结构》
北大核心
2015年第11期14-19,共6页
Steel Construction
基金
河北省自然科学基金项目(E201401853)
河北省教育厅科学研究计划青年基金项目(2011229)
关键词
随机缺陷
正放四角锥网架
损伤识别
概率设计方法
random imperfection
square pyramid space grid
damage detection
probabilistic design method
