Acoustic Emission-Based Study to Characterize the Crack Initiation Point of Wood Fiber/HDPE Composites

Abstract

The crack initiation point can be regarded as a sign of composite failure and plays a vital role in the evaluation of fracture toughness. Wood-plastic composites (WPCs) are viscoelastic materials and the evaluation of fracture mechanism and toughness has a great significance in their applications. Therefore, we used the acoustic emission (AE) technique to measure the crack initiation point of the WPCs and evaluate their fracture toughness. The results show that the novel AE-based methods were more effective than the conventional standard methods for characterization of the crack initiation point. Using the relationship of cumulative AE events with time and load, the critical failure load was quickly determined, and then the critical stress intensity factor and fracture toughness were calculated. The fracture toughness of the WPCs increased with an increase in the wood fiber content.

Determining the Stages of Deformation and Destruction of Composite Materials in a Static Tensile Test by Acoustic Emission

“…Unlike other methods, the acoustic emission (AE) [ 16 , 17 ] method is very sensitive in detecting active cracks [ 18 ], even in the beginning of plastic deformation [ 19 , 20 , 21 ]. It enables monitoring and identification of signals, ranging from microscopic deformations which influence the fracture process or cracking of fibres and matrix [ 21 , 22 , 23 ]. It can be used to characterize the delamination process and provides reliable information about the onset of delamination on a microscopic as well as on a macroscopic scale [ 24 , 25 ].…”

“…Composite damage and cracking processes are presented in the form of three stages: initial damage, deformation of the matrix, and interfacial delamination. In the article [ 23 ], the acoustic emission method was used to detect the point responsible for the crack initiation of wood fibre or recycled high-density polyethylene composites, and the fracture resistance of these materials was assessed. The results presented in the paper show that the novel AE-based methods are more effective than conventional standard methods for characterizing the point responsible for crack initiation.…”

“…The AE technique has unique advantages in the study of damage initiation and propagation, and helps to describe damage and cracking of materials together with the assessment of their resistance to these phenomena [ 23 ]. For more detailed damage monitoring, it is preferable to include an appropriate tool or signal in the analysis.…”

Wood Flour Treated with Pickering Emulsion Could Improve Its Composites with High-Density Polyethylene?

“…Wood flour, as the reinforcement in polymer matrix, has considerable interest in wood/polymer composites (WPCs) fabrication due to its advantages, such as biodegradability, renewability, and low cost [1][2][3]. As a promising alternative for nature wood, WPCs have gained increased recognition in various applications owing to their higher dimensional stability, water resistance, and fungus resistance [4,5].…”

How does Pickering Emulsion Pre-treatment Influence the Properties of Wood Flour and its Composites with High-Density Polyethylene?

“…Natural fibers like wood flour (WF) and nanocellulose are renewable sources and promising reinforcements to replace petroleum-based materials and man-made fibers [1,2,3,4]. Wood flour, as the reinforcement in polymer matrix, has considerable interest in wood/polymer composites (WPCs) fabrication due to its advantages, such as biodegradability, renewability, and low cost [5,6,7]. As a promising alternative for nature wood, WPCs have gained increased recognition in various applications owing to their higher dimensional stability, water resistance, and fungus resistance [8,9].…”