Failure mechanism during bending stress of cement-bonded particleboards analysed by acoustic emission

Failure mechanism during bending stress of cement-bonded particleboards analysed by acoustic emission

Článek WoS

The article presents research focused on evaluating the formation and progression of defects in newly developed and implemented (to production process) cement-bonded particleboard (CPB) containing secondary spruce chips from waste CPB cut-offs. The formation and progression of defects in CPB was analysed during the bending test according to EN 310 by acoustic emission (AE) and computed tomography (CT) which is unexplored area. Thus the research presented is significant because it reflects a knowledge gap. The objective of the research was to analyse the influence of the position of the AE sensors (200 mm, 240 mm, and 360 mm) and different settings of the acoustic signal filters at sensitivity thresholds of 115 %, 150 %, and 200 %. The RA and AF values characterizing tensile and shear events (defects) were determined. A methodology for α coefficient (defining the interface of the shear/tensile area) estimation based on measuring of AE shear and tensile events medians was designed and tested. For the tested CPB α = 89 kV/s² was determined. A significant finding is that in the case of bending stress on CPB, a considerable number of shear AE events can be detected. Overall, 10 % of AE events occur in elastic region of stress, when shear events dominate (76 %). The sensitivity threshold of the sensors has a significantly greater impact on the number of detected events and the tensile/shear ratio than the distance of the sensors. Distance 360 mm and threshold 150 % were determined as optimum set for CPB with 2 AE sensors. AE results and findings are supported by computed tomography.

The article presents research focused on evaluating the formation and progression of defects in newly developed and implemented (to production process) cement-bonded particleboard (CPB) containing secondary spruce chips from waste CPB cut-offs. The formation and progression of defects in CPB was analysed during the bending test according to EN 310 by acoustic emission (AE) and computed tomography (CT) which is unexplored area. Thus the research presented is significant because it reflects a knowledge gap. The objective of the research was to analyse the influence of the position of the AE sensors (200 mm, 240 mm, and 360 mm) and different settings of the acoustic signal filters at sensitivity thresholds of 115 %, 150 %, and 200 %. The RA and AF values characterizing tensile and shear events (defects) were determined. A methodology for α coefficient (defining the interface of the shear/tensile area) estimation based on measuring of AE shear and tensile events medians was designed and tested. For the tested CPB α = 89 kV/s² was determined. A significant finding is that in the case of bending stress on CPB, a considerable number of shear AE events can be detected. Overall, 10 % of AE events occur in elastic region of stress, when shear events dominate (76 %). The sensitivity threshold of the sensors has a significantly greater impact on the number of detected events and the tensile/shear ratio than the distance of the sensors. Distance 360 mm and threshold 150 % were determined as optimum set for CPB with 2 AE sensors. AE results and findings are supported by computed tomography.

Cement-bonded particleboard; bending stress; acoustic emission; distance of sensors; threshold; shear/tensile; localization

Cement-bonded particleboard; bending stress; acoustic emission; distance of sensors; threshold; shear/tensile; localization

MELICHAR, T.; DVOŘÁK, R.; TOPOLÁŘ, L.; PAZDERA, L.; DVOŘÁK, K.; NOVÁKOVÁ, I.; SKIBICKY, S.; BYDŽOVSKÝ, J.

04.07.2025

Elsevier

0950-0618

Construction and Building Materials

482

141617

Spojené království Velké Británie a Severního Irska

1

21

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https://www.sciencedirect.com/science/article/pii/S0950061825017672