Screening for internal defects of timber members based on impact evaluation method

Xin, Zhenbo; Zhang, Houjiang; Guan, Cheng; Zhang, Dian; Liu, Fenglu; Yu, Yongzhu; Guo, Kailong

doi:10.1016/j.conbuildmat.2020.120145

Cited by 2 publications

(2 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, transducers mounted on brackets can scan a large area within a short time, the measurement process can be fully automated, and the defects can be visualized using the C-scan method [12]. All these advantages make the ACU method suitable for automated industrial timber production, especially for continuous manufacturing [13][14][15][16][17].…”

Section: Introductionmentioning

confidence: 99%

Defect Detection in Solid Timber Panels Using Air-Coupled Ultrasonic Imaging Techniques

Jiang,

Wang,

Zhang

et al. 2024

Applied Sciences

View full text Add to dashboard Cite

This paper reports on investigations of the air-coupled ultrasonic (ACU) method to detect common defects in solid timber panels made of Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.). The ACU technology is a non-contact method for nondestructive timber testing with quicker scanning rates compared to contact methods. A testbed was set up consisting of commercially available piezo-ceramic ACU transducers and in-house manufactured signal processing circuits. To demonstrate the suitability of the ACU technique, through-transmission measurement results are presented for samples with defects such as knots, wormholes, and cracks. Pulse compression methods (Barker-coded method) were used to improve the power of received signals based on cross-correction algorithms. Results showed defects of timber panels made of Chinese fir can be detected with a thickness of less than 40 mm. Defects larger than 3 mm in diameter could be detected with high precision. Applying the pulse compression method showed better results than using common sine signals as excitation signals since it increased the signal-to-noise ratio, which is especially important for air-coupled measurement of high-attenuation materials like timber materials. The measurement results on reference samples demonstrated that ACU technology is a promising method for timber defect detection, especially for the quality assessment of engineered wood products.

show abstract

Section: Introductionmentioning

confidence: 99%

Defect Detection in Solid Timber Panels Using Air-Coupled Ultrasonic Imaging Techniques

Jiang,

Wang,

Zhang

et al. 2024

Applied Sciences

View full text Add to dashboard Cite

show abstract

“…In the early stage, researchers carefully distinguished the sound after knocking for preliminary screening through experience. While, in recent years, spectrum and power spectrum have been used to analyze the sounding signal for screening for wood decay and defects [35][36][37][38][39]. The wave transmission velocity method can be used for rapid screening of internal defects of wood components, and to evaluate the residual mechanical properties of wood components in conjunction with a Resistograph.…”

Section: Introductionmentioning

confidence: 99%

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

Guan

Zhang

et al. 2021

Forests

Self Cite

View full text Add to dashboard Cite

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.

show abstract

Screening for internal defects of timber members based on impact evaluation method

Cited by 2 publications

References 18 publications

Defect Detection in Solid Timber Panels Using Air-Coupled Ultrasonic Imaging Techniques

Defect Detection in Solid Timber Panels Using Air-Coupled Ultrasonic Imaging Techniques

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

Contact Info

Product

Resources

About