|Table of Contents|

Analysis of Acoustic Emission Signal by Fractal Theory in Aluminum Alloy Spot Welding(PDF)

Transactions of Tianjin University[ISSN:1006-4982/CN:12-1248/T]

Issue:
2007年03期
Page:
186-190
Publishing date:

Info

Title:
Analysis of Acoustic Emission Signal by Fractal Theory in Aluminum Alloy Spot Welding
Author(s):
LUO Zhen1DONG An1SHAN Ping1XING Zhidong2
1.School of Material Science and Engineering, Tianjin University, Tianjin 300072, China;2. Daqing Oil Field Design and Research Institute, Daqing 163712,China
Keywords:
DOI:

Abstract:
The relation between acoustic emission signal and nugget during aluminum alloy spot welding was investigated in order to evaluate spot welding quality. Due to the nonlinearity of the signals, fractal theory was utilized to quantitatively describe the characteristics of the signals instead of classical Euclidean geometry which cannot describe the acoustic emission signal accurately. Through experiments and computing, the box counting dimension is found distinct from other acoustic emission signals and is a better approach to discriminating weld nugget stages. Results show that fractal dimensions increase from 1.51 to 1.78,and they are related to nugget areas added from non-fusion to over-heated nugget.And the box counting dimension can effectively evaluate the quality of the nugget in the spot welding and can be applied with current, displace, and other spot welding parameters.

References

Memo

Memo:
-
Last Update: 2011-05-02