Stress Wave Tomography of Wood Internal Defects Based on Deep Learning and Contour Constraint Under Sparse Sampling

2019 ◽  
pp. 335-346
Author(s):  
Xiaochen Du ◽  
Jiajie Li ◽  
Hailin Feng ◽  
Heng Hu
Keyword(s):  
Deep Learning ◽  
Stress Wave ◽  
Sparse Sampling ◽  
Internal Defects ◽  
Wave Tomography

The Study of Stress Wave Tomography Algorithm for Internal Defects in RL Plane of Wood

2018 ◽  
Author(s):  
Hailin Feng ◽  
Zheng Qian ◽  
Mingyue Hu ◽  
Zeyu Zheng ◽  
Xiaochen Du
Keyword(s):  
Stress Wave ◽  
Internal Defects ◽  
Wave Tomography

scholarly journals Stress Wave Tomography of Wood Internal Defects using Ellipse-Based Spatial Interpolation and Velocity Compensation

BioResources ◽  
2015 ◽  
Vol 10 (3) ◽  
Author(s):  
Xiaochen Du ◽  
Shaozhe Li ◽  
Guanghui Li ◽  
Hailin Feng ◽  
Shengyong Chen
Keyword(s):  
Stress Wave ◽  
Spatial Interpolation ◽  
Internal Defects ◽  
Wave Tomography

scholarly journals Application of Nondestructive Testing Technologies in Preserving Historic Trees and Ancient Timber Structures in China

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 318
Author(s):  
Pengfei Xu ◽  
Cheng Guan ◽  
Houjiang Zhang ◽  
Guanghui Li ◽  
Dong Zhao ◽  
...  
Keyword(s):  
Nondestructive Testing ◽  
Stress Wave ◽  
Digital Imaging ◽  
Visual Inspection ◽  
Wave Transmission ◽  
Theoretical Research ◽  
Timber Structures ◽  
Internal Defects ◽  
Wave Tomography ◽  
Transmission Velocity

In China, preserving historic trees and ancient timber structures has attracted more attention from researchers and institutions. Nondestructive testing (NDT) technology has gained momentum in the application and research in recent years. This paper presents some examples of the application of NDT techniques in the protection of historic trees and ancient timber structures in China. A total of nine NDT techniques were applied, including five techniques of visual inspection, sounding, Resistograph, stress wave transmission velocity, stress wave tomography for both historic trees and ancient timber structures, two techniques of the pulling-test and ground-penetrating radar (GPR) for historic trees alone, and two techniques of acoustic emission (AE) and digital imaging for ancient timber structures. Based on field testing, there is a very good detecting effect for visual inspection and Resistograph, but sounding works unsatisfactorily. The stress wave transmission velocity is found to be excellent in screening for the internal defects of historic tree trunks, but performs badly in screening for the internal defects within the wood members of ancient timber structures. AE is less successful but digital imaging performs well in long-term monitoring and damage warning of wood structures. The stress wave tomography successfully obtains images of internal defects inside tree trunks. The anchorage of some historic trees cannot be quantitatively evaluated with the pulling test if the tree is too large. GPR’s resolution and accuracy are very low, which limit its application. Theoretical research on NDT and promotion of NDT technology are still an essential part of the work in the future.

scholarly journals Minimally Invasive Detection Technologies for the Defects in Ancient Timber Structural Building

2018 ◽  
Vol 777 ◽  
pp. 476-482
Author(s):  
Pei Xuan Wang ◽  
Wei Zhang ◽  
Sheng Cai Li ◽  
Chang Yong Hu ◽  
Nicola Macchioni ◽  
...  
Keyword(s):  
Minimally Invasive ◽  
Stress Wave ◽  
Detection Method ◽  
Timber Structures ◽  
Wave Tomography ◽  
Detection Technologies

How to examine and describe the defects in timber is vital for assessing the performance of an ancient timber structural building. This paper mainly elaborates the methodology of detecting the defects in ancient timber structures. The detection method includes preliminary condition survey, stress-wave tomography test, and correction with resistographic drilling. By means of above detection, the defects inside a timber structural building could be described more accurately.

scholarly journals Electric resistance tomography and stress wave tomography for decay detection in trees—a comparison study

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6444 ◽  
Author(s):  
Xiaoquan Yue ◽  
Lihai Wang ◽  
James P. Wacker ◽  
Zhiming Zhu
Keyword(s):  
Stress Wave ◽  
Ordinary Least Squares ◽  
Operating Conditions ◽  
Strong Positive Correlation ◽  
Least Squares Regression ◽  
Electric Resistance ◽  
Correlation Relationship ◽  
Positive Correlation ◽  
Standing Trees ◽  
Wave Tomography

Background To ensure the safety of trees, two NDT (nondestructive testing) techniques, electric resistance tomography and stress wave tomography, were employed to quantitatively detect and characterize the internal decay of standing trees. Comparisons between those two techniques were done to make full use of the individual capability for decay detection. Methods Eighty trees (40 Manchurian ash and 40 Populus simonii) were detected, then wood increment cores were obtained from each cross disc trial. The Dt, which was defined as the value determined by the mass loss ratio of each wood core, was regarded as the true severity of decay. Using ordinary least-squares regression to analyze the relationship between Dt and De (De was defined as the severity of decay determined by electric resistance tomography) and between Dt and Ds (Ds was defined as the severity of decay determined by stress wave tomography). Results The results showed that both methods could estimate the severity of decay in trees. In terms of different stages of decay, when Dt < 30%, De had a strong positive correlation with Dt (R2 = 0.677, P < 0.01), while, when Dt ≥ 30%, Ds had a significant positive correlation relationship with Dt (R2 = 0.645, P < 0.01). Conclusion Electric resistance tomography was better than stress wave tomography for testing in the early stages of decay, while stress wave tomography can be used effectively in the late stage of decay. It is suggested that each technique can be used in the practice of internal decay testing of standing trees based on decay stages and operating conditions.

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