Determination of Correlation between Destructive and Nondestructive Test Methods Applied on Modified Wood Exposed to Natural Weathering

Abstract

The objective of this study was to determine a correlation between the dynamic modulus of elasticity (MOEd) and the static modulus of elasticity (MOEs), and to assess the potential of using nondestructive (NDT) methods as a grading tool for both treated and untreated wood exposed to weathering. In the experiment, test samples made from spruce and oak were exposed for four months to natural weathering. Half of the specimens were treated with a silicon-based nano-protection. The MOEd was determined using acoustic NDT methods-ultrasound transmission (MOEdu) and the vibration methods (MOEdv), while the MOEs was determined by a destructive three-point bending test. The results showed that there was no statistical significance for the influence of the time of exposure and the surface treatment on the modulus of elasticity. The ultrasound method, measured in the longest distance of the sample, had the most significant correlation with the MOEs. The vibration method also reached a similar correlation with the MOEs. The mean values of the MOEdu and MOEdv were higher than the MOEs. The influence of density on the acoustic wave velocity was not confirmed.

Performance of Thermally Modified Spruce Timber in Outdoor Above-Ground Conditions: Checking, Dynamic Stiffness and Static Bending Properties

“…Overall, the axial dynamic stiffness of TM and unmodified spruce timber did not change during 30 months of weathering in South Sweden. This is consistent with earlier research into the effect of 4 months of natural weathering on E a of small clear wood of spruce [78].…”

“…Overall, the axial dynamic stiffness of TM and unmodified spruce timber did not change during 30 months of weathering in South Sweden. This is consistent with earlier research into the effect of 4 months of natural weathering on Ea of small clear wood of spruce [78]. Before and after exposure (i.e., when boards were conditioned), differences in MC at the time of testing were smaller than during weathering for both control and TM boards (Table 4 and Figure 8a).…”

Influence of treatment with water-soluble CCB preservative on the physical-mechanical properties of brazilian tropical timber

“…When wood is outdoor exposed to environment without going through appropriate preservative treatment, its biodeterioration occurs 7,8 . Wood properties are changed due to physical, chemical, mechanical or biological agents, the latter being xylophagous organisms 2,9 .…”

Defect Characteristics and Online Detection Techniques During Manufacturing of FRPs Using Automated Fiber Placement: A Review

“…Stress waves can identify internal defects because the defects can change the characteristics of stress wave propagation. The stress wave has been widely used in non-destructive testing in the field of geology [125][126][127], tree damage diagnosis [128][129][130], and composites [131][132][133][134][135]. Han et al [111] used the stress wave to detect online the internal defects during the AFP process, where continuous loading induced by the process itself was used as an excitation source without another external excitation (see Figure 12).…”