Evaluation of Adhesive Interface Properties in Honeycomb Sandwich Structure Using Guided Waves

2021 ◽  
Author(s):  
Parambeer Singh Negi ◽  
Dileep Koodalil ◽  
Krishnan Balasubramaniam
Keyword(s):  
Wave Propagation ◽  
Sandwich Structure ◽  
Guided Waves ◽  
Wave Mode ◽  
Guided Wave ◽  
Sh Wave ◽  
Bond Quality ◽  
Honeycomb Sandwich ◽  
Oriented Parallel ◽  
Honeycomb Sandwich Structure

Abstract A method is presented to evaluate the interfacial weakness of aluminium-based honeycomb sandwich structure (HSS) using Shear Horizontal (SH) guided wave. SH guided waves are sensitive to the interfacial properties since the wave particles vibration is oriented parallel to the adhesive-adherent joints. Periodic permanent magnet (PPM) electromagnetic acoustic transducers (EMATs) are used to excite and detect SH-guided waves. A semi-analytical finite element method is developed to simulate the SH wave propagation in HSS. The boundary stiffness approach is used to model the adhesive-adherent interface. The excitation parameters are chosen such that only SH0 mode is generated in the structure. The interaction of the fundamental SH0 wave mode with various defects and the different interface stiffness is analyzed. The frequency-wavenumber analysis is used to study the effect of interface stiffness on SH wave propagation. The analysis reveals that in a perfect bond, SH0 and S0 guided modes are present. The interaction of SH0 mode with the honeycomb core results in the genesis of S0 mode. Thus, the presence or absence of the S0 mode can be used as an indicator of bond quality. The findings from the FE simulation are validated against the experiment. The analysis shows a reliable non-destructive evaluation of the interface joint and classifying them as good or bad bonds.

Study of Guided Wave Propagation in Honeycomb Sandwich Structures

2014 ◽  
Author(s):  
Zhenhua Tian ◽  
Guoliang Huang ◽  
Lingyu Yu
Keyword(s):  
Wave Propagation ◽  
Guided Waves ◽  
Sandwich Structures ◽  
Guided Wave ◽  
Experimental Results ◽  
Fe Model ◽  
Laser Vibrometry ◽  
Honeycomb Core ◽  
Guided Wave Propagation ◽  
Honeycomb Sandwich

This paper studies the guided waves in honeycomb sandwich structures and explores the ability of guided waves for the debonding damage detection. Both the finite element (FE) simulations and laser vibrometry experiments are used. A three-dimensional (3D) FE model is built to simulate the guided waves in a honeycomb sandwich plate. The simulation results show the guided waves in the structure depend on the wave frequency. At low frequencies, the global guided waves propagate in the entire sandwich, while leaky guided waves dominate in the skin panel at high frequencies. To further understand the guided wave propagation fundamentals, laser vibrometry experiments are performed. The waveforms, time-space wavefields, and frequency-wavenumber spectra obtained from the experiments are used to unveil the wave propagation features. The experimental results confirm the leaky guided waves. Moreover, the experimental results show the complex wave interactions induced by the honeycomb core. When the debonding between the skin and honeycomb core presents, the guided wave amplitude increases, and the wave interaction with the honeycomb core reduces.

High-Frequency Vibration Response of Metal Honeycomb Sandwich Structure

2009 ◽  
Vol 79-82 ◽  
pp. 1727-1730 ◽  
Author(s):  
Xiao Dong He ◽  
Xiang Hao Kong ◽  
Li Ping Shi ◽  
Ming Wei Li
Keyword(s):  
High Frequency ◽  
Sandwich Structure ◽  
Dynamic Pressure ◽  
Vibration Response ◽  
Element Analysis ◽  
High Frequency Vibration ◽  
Honeycomb Sandwich ◽  
Vibration Experiment ◽  
Aerial Vehicle ◽  
Honeycomb Sandwich Structure

ARMOR TPS panel is above the whole ARMOR TPS, and the metal honeycomb sandwich structure is the surface of the ARMOR TPS panel. So the metal honeycomb sandwich structure plays an important role in the ARMOR TPS, while it bears the flight dynamic pressure and stands against the flight dynamic calefaction. So the active environment of metal honeycomb sandwich structure is very formidable. We have to discuss any extreme situation, for reason of making sure aerial vehicle is safe. And high-frequency vibration is one of active environment. In this paper we have analyzed high-frequency vibration response of metal honeycomb sandwich structure. We processed high-frequency vibration experiment by simulating true aerial environment. Sequentially we operated high-frequency vibration experiment of metal honeycomb sandwich structure with cracks, notches and holes. Then finite-element analysis was performed by way of validating the experiment results. Haynes214 is a good high temperature alloy material of both face sheet and core at present, so we choose it in this paper.

scholarly journals Numerical Simulation on Micro-damage Detection In CFRP Composites Based on Nonlinear Ultrasonic Guided Waves

2021 ◽  
Keyword(s):  
Damage Detection ◽  
Composite Structures ◽  
Guided Waves ◽  
Second Harmonic ◽  
Wave Mode ◽  
Guided Wave ◽  
Reinforced Plastics ◽  
Matrix Cracks ◽  
Nonlinear Ultrasonic ◽  
Contact Acoustic Nonlinearity

Abstract. Micro-damages such as pores, closed delamination/debonding and fiber/matrix cracks in carbon fiber reinforced plastics (CFRP) are vital factors towards the performance of composite structures, which could collapse if defects are not detected in advance. Nonlinear ultrasonic technologies, especially ones involving guided waves, have drawn increasing attention for their better sensitivity to early damages than linear acoustic ones. The combination of nonlinear acoustics and guided waves technique can promisingly provide considerable accuracy and efficiency for damage assessment and materials characterization. Herein, numerical simulations in terms of finite element method are conducted to investigate the feasibility of micro-damage detection in multi-layered CFRP plates using the second harmonic generation (SHG) of asymmetric Lamb guided wave mode. Contact acoustic nonlinearity (CAN) is introduced into the constitutive model of micro-damages in composites, which leads to the distinct SHG compared with material nonlinearity. The results suggest that the generated second order harmonics due to CAN could be received and adopted for early damage evaluation without matching the phase of the primary waves.

Detection of Defects in Titanium Using Shear Horizontal Guided Waves

2021 ◽  
Author(s):  
Christian Peyton ◽  
Rachel S. Edwards ◽  
Steve Dixon ◽  
Ben Dutton ◽  
Wilson Vesga
Keyword(s):  
Guided Waves ◽  
Wave Mode ◽  
Guided Wave ◽  
Inspection System ◽  
Wave Direction ◽  
Finite Element Software ◽  
Small Defect ◽  
Back Face ◽  
The Relationship ◽  
Shear Horizontal

Abstract This paper investigates the interaction behaviour between the fundamental shear horizontal guided wave mode and small defects, in order to understand and develop an improved inspection system for titanium samples. In this work, an extensive range of defect sizes have been simulated using finite element software. The SH0 reflection from a defect has been shown previously to depend on its length as the total reflection consists of reflections from both the front and back face. However, for small defect widths, this work has found that the width also affects this interference, changing the length at which the reflection is largest. In addition, the paper looks at how the size of the defect affects the mode converted S0 reflection and SH0 diffraction. The relationship between the SH0 diffraction and defect size is shown to be more complex compared to the reflections. The mode converted S0 reflection occurs at an angle to the incident wave direction; therefore, the most suitable angle for the detection has been found. Simultaneous measurement of multiple waves would bring benefits to inspection.

Honeycomb-Cored Sandwich Structure Composites

2010 ◽  
pp. 223-235
Keyword(s):  
Composite Materials ◽  
Sandwich Structure ◽  
Complex Structure ◽  
Failure Mechanisms ◽  
Resin System ◽  
Lower Weight ◽  
Film Adhesive ◽  
Adhesive Prepreg ◽  
Honeycomb Sandwich ◽  
Honeycomb Sandwich Structure

Abstract The honeycomb sandwich structure composite is a very efficient and complex structure widely used in the aircraft industry. Honeycomb-cored sandwich panels increase part stiffness at a lower weight than monolithic composite materials. This chapter describes the analysis of the intermingling of the film adhesive/prepreg resin system. It discusses the causes and effects of honeycomb core movement, which results in core crush. The chapter also explains the formation of a void in honeycomb composites and the failure mechanisms in honeycomb sandwich structure composites.

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