呼吸裂纹梁非线性动力特性研究

胡家顺;冯新;周晶

振动与冲击 ›› 2009, Vol. 28 ›› Issue (1) : 76-80,8.

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振动与冲击 ›› 2009, Vol. 28 ›› Issue (1) : 76-80,8.
论文

呼吸裂纹梁非线性动力特性研究

  • 胡家顺,冯新,周晶
作者信息 +

STUDY ON THE NONLINEAR DYNAMIC RESPONSE OF A BEAM WITH A BREATHING CRACK

  • Hu JiaShun,Feng Xin,Zhou Jing
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文章历史 +

摘要

疲劳裂纹是结构损伤的重要形式,是引起结构破坏的主要因素之一。建立了含非对称疲劳裂纹梁的非线性数值分析模型,采用奇异单元模拟裂纹尖端的效应,使用无摩擦的接触单元模拟疲劳裂纹的张开闭合特性,研究了结构在简谐荷载激励下的非线性动力特性。以悬臂梁为例分别分析了外部激励频率、裂纹深度以及裂纹位置等参数的变化对系统非线性行为的影响,重点讨论了系统的亚谐、超谐等共振现象,并且提出了系统频率的相对幅值用于辨识裂纹深度的方法。研究结果为裂纹结构的损伤识别提供了一定的理论基础和参考。

Abstract

Fatigue crack is one of the main damages existing on the structural members, which can lead to structure failure due to repeated loads. The nonlinear dynamic characteristics of a cantilever beam with a non-propagating asymmetric fatigue crack subjected to a harmonic load at the tip are studied. A breathing crack model is introduced to describe the nonlinear dynamic behavior of fatigue crack and can be simulated as a frictionless contact plane problem. Meanwhile, the quarter-point element is used to simulate the crack tip effects. Based on the proposed model, the effects of various factors, such as the excitation frequency, crack depth and crack position on nonlinear dynamic characteristics are discussed in detail. A relatively amplitude of system frequency is proposed to detect the crack severity based on the analysis of the sub-harmonics and super-harmonics at the crack interfaces. The results provide theory and reference for damage identification of cracked structure at some extent.

关键词

呼吸裂纹 / 接触分析 / 亚谐共振 / 超谐共振 / 幅值谱

Key words

breathing crack / contact analysis / sub-harmonics / super-harmonics / amplitude spectra

引用本文

导出引用
胡家顺;冯新;周晶. 呼吸裂纹梁非线性动力特性研究[J]. 振动与冲击, 2009, 28(1): 76-80,8
Hu JiaShun;Feng Xin;Zhou Jing. STUDY ON THE NONLINEAR DYNAMIC RESPONSE OF A BEAM WITH A BREATHING CRACK[J]. Journal of Vibration and Shock, 2009, 28(1): 76-80,8
中图分类号: TU311.41   

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