Acoustic Emission Characteristics of Different Bamboo and Wood Materials in Bending Failure Process

Ting Wang,Yin Yang,Jianhui Zhou,Zhiqiang Wang

doi:10.32604/jrm.2022.017955

Abstract

The acoustic emission (AE) technique can perform non-destructive monitoring of the internal damage development of bamboo and wood materials. In this experiment, the mechanical properties of different bamboo and wood (bamboo scrimber, bamboo plywood and SPF (Spruce-pine-fir) dimension lumber) during four-point loading tests were compared. The AE activities caused by loadings were investigated through the single parameter analysis and K-means cluster analysis. Results showed that the bending strength of bamboo scrimber was 3.6 times that of bamboo plywood and 2.7 times that of SPF dimension lumber, respectively. Due to the high strength and toughness of bamboo, the AE signals of the two bamboo products were more abundant than those of SPF dimension lumber. However, the AE evolution trend of the three materials was similar, which all experienced three stages, including gentle period, steady period and steep period, and the area of rupture precursor characteristics could be recognized before the specimen destroyed. Due to the bottom layer was first tensile failure, the main structure of bamboo plywood was destroyed after the stress redistribution. The rupture precursor characteristics could be observed before each peak. Findings put in evidence a good correlation between AE clusters of two bamboo products, while the amplitude and energy of wood signals were lower than those of bamboo. The amplitude and energy from the propagation and aggregation of cracks were greater than those related to micro-cracks initiation.

Highlights

With the increasingly prominent environmental problems and the declining available resources, the engineered wood products and engineered bamboo products for structures have received more and more attention
The research work we present here mainly focused on the effect of material kinds on acoustic emission (AE) signals during the four-point bending tests
Through AE parameter analysis and K-means cluster analysis, the AE activities were correlated with the loading process, and the AE signal characteristics of different damage mechanisms were explored

Summary

Introduction

With the increasingly prominent environmental problems and the declining available resources, the engineered wood products and engineered bamboo products for structures have received more and more attention. Both wood and bamboo are renewable materials with the ability to sequester carbon, which show a better strength-to-weight ratio than steel or concrete [1]. As a non-destructive testing technology capable of real-time online dynamic monitoring, acoustic emission (AE) techniques have been widely used in the field of wood materials, mainly focusing on the evaluation of wood mechanical properties, wood machining, and drying detection [12]. Through AE parameter analysis and K-means cluster analysis, the AE activities were correlated with the loading process, and the AE signal characteristics of different damage mechanisms were explored

Material

Four-Point Bending Test and AE Instrumentation

Results and Discussion

Acoustic Emission Activity

Conclusion