Damage Index Comparison for a Composite Stiffened Panel Using Lamb Wave

2007 ◽  
Vol 26-28 ◽  
pp. 1265-1268 ◽  
Author(s):  
Chan Yik Park
Keyword(s):  
Lead Zirconate Titanate ◽  
Lamb Waves ◽  
Impact Damage ◽  
Damage Index ◽  
Lead Zirconate ◽  
Low Velocity Impact ◽  
Stiffened Panel ◽  
Low Velocity ◽  
Composite Stiffened Panel ◽  
Index Comparison

Various damage index (DI) algorithms of detecting changes such as a loosen bolt and a delamination development in a composite structure were examined using ultrasonic Lamb waves generated by embedded piezoelectric active sensors. The DI is a single value that is a function of response signal’s attenuation due to any damage or changes in a structure. Various DI algorithms such as active damage interrogation (ADI), time domain root men square (RMS), short time Fourier Transform (STFT) and time reversal (TR) were discussed. For experimental validation, a composite stiffened panel was used, and loosen bolt damage and low-velocity- impact damage were tested. In order to pitch and catch Lamb waves, surface mounted PZTs (lead zirconate titanate) were used. According to the DI algorithms, appropriate ultrasonic guided Lamb waves were selected for actuators. Each set of DI algorithm and drive signal showed different characteristics to detect the damage.

Passive Damage Detection of Natural Fibre Reinforced Composites Using Sensor Response Data

2014 ◽  
Vol 534 ◽  
pp. 17-23 ◽  
Author(s):  
M. Zaleha ◽  
Shahruddin Mahzan ◽  
M.I. Idris
Keyword(s):  
Lead Zirconate Titanate ◽  
Impact Damage ◽  
Lead Zirconate ◽  
Optical Microscope ◽  
Natural Fibre ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Damage Initiation ◽  
Response Data ◽  
Sensor Signals

This paper presents the detection of impact damage in a natural fibre reinforced composite plate under low velocity impact damage. Lead Zirconate Titanate (PZT) sensors were placed at ten different positions on each plate in order to record the response signals. The response signals captured from each sensor were collected for impacts performed by a data acquisition system. The impacted plates were examined with optical microscope to examine the damaged areas. It was found that the damaged size grew proportionally with impact force. The results also revealed that PZT sensors can be used to detect the damage extent with the waveform of sensor signals implying the damage initiation and propagation which detected above the damage force of 150N.

scholarly journals Experimental Study on Fibre Reinforced Resin-Based Composite Stiffened Panel with Low Velocity Impact Damage under Shearing Load

2017 ◽  
Vol 26 (3) ◽  
pp. 096369351702600
Author(s):  
Tao An ◽  
Yv Feng ◽  
Yvting He
Keyword(s):  
Failure Modes ◽  
Failure Load ◽  
Impact Damage ◽  
Engineering Application ◽  
Load Test ◽  
Low Velocity Impact ◽  
Stiffened Panel ◽  
Low Velocity ◽  
Velocity Impact ◽  
Composite Stiffened Panel

Drop hammer impact tests on the Fibre Reinforced Resin-Based composite stiffened panels are used to make low velocity impact damage. And then shearing experiments on impacted specimen and intact ones are conducted to obtain the buckling load and failure load. Test results of impacted specimens and intact ones are compared to analyse the effect of damage on the carrying capacity of the structure. The results show that there is no obvious buckling during the tests for two kinds of panels. But the low velocity impact damage on the panel can reduce the failure load of the structure a lot. The failure modes mainly contain damage of four corners, cleaving of skin and deformation of specimen and so on. The experimental results offer some valuable references to engineering application of the structure.

Structural Health Monitoring of Composite Structures Using Guided Lamb Waves

2006 ◽  
Vol 321-323 ◽  
pp. 759-764 ◽  
Author(s):  
Krishnan Balasubramaniam ◽  
B.V. Soma Sekhar ◽  
J. Vishnu Vardan ◽  
C.V. Krishnamurthy
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Composite Structures ◽  
Lamb Waves ◽  
Impact Damage ◽  
Composite Plates ◽  
Structural Features ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Structural Health

Structural Health Monitoring (SHM) of aircrafts is of great relevance in the present age aircraft industry. The present study demonstrates three techniques that have the potential for the SHM of multi-layered composite structures. The first technique is based on multi-transmitter-multireceiver (MTMR) technique with tomographic methods used for data reconstruction. In the MTMR, the possibility of SHM using algebraic reconstruction techniques (ART) for tomographic imaging with Lamb wave data measured in realistic materials is examined. Defects (through holes and low velocity impact delaminations) were synthetic and have been chosen to simulate impact damage in composite plates. The second technique is a single-transmitter-multi-receiver (STMR) technique that is more compact and uses reconstruction techniques that are analogous to synthetic aperture techniques. The reconstruction algorithm uses summation of the phase shifted signals to image the location of defects, portions of the plate edges, and any reflectors from inherent structural features of the component. The third technique involves a linear array of sensors across a stiffener for the detection of disbanded regions.

Kernel Feature Space Based Low Velocity Impact Monitoring

2012 ◽  
Author(s):  
Yingtao Liu ◽  
Masoud Yekani Fard ◽  
Aditi Chattopadhyay
Keyword(s):  
Composite Structures ◽  
Impact Damage ◽  
Damage Index ◽  
Low Velocity Impact ◽  
Kernel Principal Component Analysis ◽  
Monitoring Methods ◽  
Low Velocity ◽  
Velocity Impact ◽  
Statistical Feature ◽  
The Impact

Impact damage has been identified as a critical form of defect that constantly threatens the reliability of composite structures, such as those used in aircrafts and naval vessels. Low energy impacts can introduce barely visible damage and cause structural degradation. Therefore, efficient structural health monitoring methods, which can accurately detect, quantify, and localize impact damage in complex composite structures, are required. In this paper a novel damage detection methodology is demonstrated for monitoring and quantifying the impact damage propagation. Statistical feature matrices, composed of features extracted from the time and frequency domains, are developed. Kernel Principal Component Analysis (KPCA) is used to compress and classify the statistical feature matrices. Compared with traditional PCA algorithm, KPCA method shows better feature clustering and damage quantification capabilities. A new damage index, formulated using Mahalanobis distance, is defined to quantify impact damage. The developed methodology has been validated using low velocity impact experiments with a sandwich composite wing.

scholarly journals Impact Damage Detection in Patch-Repaired CFRP Laminates Using Nonlinear Lamb Waves

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 219
Author(s):  
Zhenhua Yin ◽  
Cheng Li ◽  
Ying Tie ◽  
Yuechen Duan
Keyword(s):  
Lamb Wave ◽  
Lamb Waves ◽  
Detection System ◽  
Impact Damage ◽  
Impact Resistance ◽  
Numerical Procedure ◽  
Low Velocity Impact ◽  
Patch Repair ◽  
Low Velocity ◽  
Cfrp Laminates

Carbon fiber-reinforced polymer (CFRP) laminates, a key composite material, are widely used in aircraft structures and are susceptible to low-velocity impact (LVI) damage from bird strikes, lightning strikes, hail impacts and other situations. Therefore, finding a method that repairs the damaged structure and detects the effect of these repairs under LVI is a very important goal. In this work, the repair effect of LVI damage in CFRP laminates repaired with patches of various sizes is investigated via experimental and numerical nonlinear Lamb wave analyses. An integrated numerical procedure that combines LVI with nonlinear Lamb wave detection is developed to predict the nonlinear Lamb wave behavior in LVI-damaged patch-repaired CFRP laminates. The CFRP laminate damage in the nonlinear Lamb wave simulation is evaluated based on relative acoustic nonlinearity parameters (RANPs). As a result, the integrated numerical procedure is validated with drop-weight impact tests and RAM-5000 SNAP nonlinear ultrasonic detection system. An optimal patch design is established via interpolation to optimize the absorbed energy, delamination surface area, second RANP and third RANP with different patch repair sizes. These parameters exhibit consistent curve fitting trends, indicating that they can be used as important indicators of impact damage. The optimal circular patch design with a radius of 2.5 r has better impact resistance behavior and repair performance.

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