Some Issues in Passive Impact Location Detection Triangulation in Composite Materials Using Embedded Piezoelectric Sensors

2012 ◽  
Author(s):  
Bruno Zamorano-Senderos ◽  
Niell Elvin ◽  
Samuel Shin
Keyword(s):  
Evaluation Method ◽  
Residual Life ◽  
Impact Damage ◽  
Computational Cost ◽  
Piezoelectric Sensors ◽  
New Technique ◽  
Impact Location ◽  
Location Detection ◽  
Extent Of Damage ◽  
The Impact

This paper studies some aspects of impact location detection in composites materials using triangulation methods with embedded piezoelectric sensors. The first step of any impact damage evaluation method is to ascertain if an impact has happened and its location. More sophisticated methods (not addressed in this paper) can then be used to determine the type and extent of damage and to estimate the residual life of the structure. We propose a novel sensor array that potentially reduces the number of computations required to locate the position of the impact and reduces the complexity of embedded sensor wiring. Reducing the computational complexity allows the use of lighter, cheaper and less energy consuming electronic devices. The new technique reduces the classical computation from a planar (two dimensional) search to an angular (one dimensional) search. The new technique is experimentally compared with a classical triangulation technique at moderate ballistic speeds (300 m/s). This paper shows that the new technique reduces the computational cost, but also reduces accuracy of impact location.

scholarly journals Numerical Investigation on the Ultimate Strength of Box Beams with Impact Damage

2020 ◽  
Author(s):  
Wei Xu ◽  
C. Guedes Soares
Keyword(s):  
Residual Stress ◽  
Ultimate Strength ◽  
Impact Damage ◽  
Ship Hulls ◽  
Four Point Bending ◽  
Impact Location ◽  
Box Beam ◽  
Box Beams ◽  
Fracture Damage ◽  
The Impact

AbstractThe objective of this paper is to study the residual ultimate strength of box beams with impact-induced damage, as a model of what may occur in ship hulls. The bottom and side plates of ship hulls can suffer denting or fracture damage due to grounding, collision and other contacts during the ship’s service life and these impact-induced damages could result in considerable strength degradation. Box beams are firstly subjected to impact loading and then four-point bending loading is imposed on the damaged structures to assess the residual strength using ANSYS/LS_DYNA. The ultimate moment and collapse modes are discussed considering the effect of impact location. The impact-induced deformation is introduced in the four-point bending simulation, and the impact-induced stress is included or not to determine the effect of residual stress and distortion after impact. It is shown that impact location has significant influence on the residual ultimate bending moment of the damaged box beam providing that the impact energy is kept constant. The collapse modes also change when the impactor strikes on different locations. Damaged hard corner and inclined neutral axes might explain the reduction of ultimate strength and diverse collapse modes. The residual stress in the box beam after impact may increase or decrease the ultimate strength depending on impact location.

An Enhanced Time-Reversal Method for Impact Damage Monitoring on Plate-Like Structures

2012 ◽  
Vol 525-526 ◽  
pp. 365-368
Author(s):  
Chun Lin Chen ◽  
Yu Long Li ◽  
Fuh Gwo Yuan
Keyword(s):  
Time Reversal ◽  
Composite Structures ◽  
Impact Damage ◽  
High Energy ◽  
Low Velocity ◽  
Energy Impact ◽  
Location Detection ◽  
Focusing Property ◽  
The Impact ◽  
Impact Events

Based on the self-focusing property of time-reversal (T-R) concept, a time focusing parameter was suggested to improve the impact source identification method developed in authors previous work. This paper presents a further study on monitoring relatively high energy impact events which caused induced damage on structures. Numerical verifications for a finite isotropic plate and a composite plate under low velocity impacts are performed to demonstrate the versatility of T-R method for impact location detection with induced plastic deformation and delamination damage on metallic and composite structures respectively. The focusing property of T-R concept was adequately utilized to detect impact/damage location. The results show that impact events with various features can be localized using T-R method by introducing the time focusing parameter. It is suited to monitor serious impact events on plate like structures in practice in future.

scholarly journals Development of Time-Reversal Method for Impact Source Identification on Plate Structures

2013 ◽  
Vol 20 (3) ◽  
pp. 561-573 ◽  
Author(s):  
Chunlin Chen ◽  
Yulong Li ◽  
Fuh-Gwo Yuan
Keyword(s):  
Impact Loading ◽  
Time Reversal ◽  
Source Identification ◽  
Transfer Functions ◽  
Plate Thickness ◽  
Time History ◽  
Numerical Verification ◽  
Impact Location ◽  
Location Detection ◽  
The Impact

This paper presents a detailed study on the impact source identification of a plate structure using time-reversal (T-R) method. Prior to impact monitoring, the plate is calibrated (or characterized) by transfer functions at discrete locations on the plate surface. Both impact location and impact loading time-history are identified using T-R technique and associated signal processing algorithms. Numerical verification for finite-size isotropic plates under low velocity impacts is performed to demonstrate the versatility of T-R method for impact source identification. The tradeoff between accuracy of the impact location detection and calibration spacing is studied in detail. In particular, the effect of plate thickness on calibration spacing has been examined. A number of parameters selected for determining the impact location, approximated transfer functions and steps taken for reconstructing the impact loading time-history are also examined. Two types of noise with various intensities contaminated in strain response and/or transfer functions are investigated for demonstrating the stability and reliability of the T-R method. The results show that T-R method is robust against noise in impact location detection and force reconstruction in circumventing the inherent ill-conditioned inverse problem. Only transfer functions are needed to be calibrated and four sensors are requested in T-R method for impact identification.

Fatigue Behavior of Impacted Carbon/Epoxy Laminates under 2-Stage Block Loading

2006 ◽  
Vol 306-308 ◽  
pp. 199-204
Author(s):  
Ki Weon Kang ◽  
Jung Kyu Kim ◽  
Yong Su Kim ◽  
Young Min Do
Keyword(s):  
Fatigue Life ◽  
Composite Laminates ◽  
Residual Life ◽  
Impact Damage ◽  
Fatigue Behavior ◽  
Equivalent Stress ◽  
Damage Parameter ◽  
Experimental Results ◽  
Block Loading ◽  
The Impact

The paper presents the fatigue behavior of carbon/epoxy laminates with impact-induced damage under 2-stage block loading. The impact damage parameter is proposed to evaluate the effect of impact damage on fatigue life. Based on this parameter, the model is developed to predict the residual life at second block. Also, the model for equivalent stress is proposed to estimate the fatigue life under 2-stage block loading based on the S-N curves under constant amplitude loading. For these models, the 2-stage block loading fatigue tests were performed on the impacted composite laminates. The effect of impact damage on fatigue life under 2-stage block loading can be characterized by the impact damage parameter. Additionally, the results by the present residual life prediction model agree with experimental results regardless of applied impact energy. Also, the equivalent stress and corresponding fatigue life by the present model agrees well with the experimental results.

scholarly journals Multichannel Real-Time Electronics Platform for the Estimation of the Error in Impact Localization With Different Piezoelectric Sensors Density

2021 ◽  
Author(s):  
Lorenzo Capineri ◽  
Andrea Bulletti ◽  
Eugenio Marino Merlo
Keyword(s):  
Real Time ◽  
Error Function ◽  
Electronic System ◽  
Position Estimation ◽  
Piezoelectric Sensors ◽  
Signal Acquisition ◽  
Time Of Arrival ◽  
Impact Location ◽  
The Impact ◽  
Impact Localization

The work presents a Structural Health Monitoring (SHM) electronic system with real-time ac-quisition and processing for the determination of impact location in laminates. The novelty of this work is the quantitative evaluation of impact location errors using the Lamb wave guided mode S0, captured and processed in real-time by up to eight piezoelectric sensors. The differential time of arrival is used to minimize an error function for the position estimation. The impact energy is correlated to the amplitudes of the antisymmetric (A0 ) mode and the electronic design is de-scribed to avoid saturation for signal acquisition. The same electronic is designed to acquire symmetric (S0 ) low level signals by adequate gain, bandwidth and signal to noise ration. Such signals propagate into a 1.4mm thick aluminum laminate at the group velocity of 5150m/s with frequency frequency components above 270kHz and can be discriminated from the A0 mode to calculate accurately the differential arrival time. The results show that the error is not improved better than S0 wavelength in impact localization by using six out of eight sensors connected to the electronic system.

scholarly journals Numerical simulation on Crashworthiness of 105000t LNG Carrier

2021 ◽  
Vol 2083 (3) ◽  
pp. 032037
Author(s):  
Qian Sun ◽  
Jianmin Liu ◽  
Hong Zhou
Keyword(s):  
Numerical Simulation ◽  
Impact Damage ◽  
Impact Angle ◽  
Practical Significance ◽  
Structural Repair ◽  
Impact Location ◽  
Force Velocity ◽  
Finite Element Numerical Simulation ◽  
Bulbous Bow ◽  
The Impact

Abstract It is of great significance to study the crashworthiness of LNG carrier to improve its crashresistance and enhance its operation safety. In this paper, the collision process between the bulbous bow of the container ship and the side structure of the LNG ship is analyzed by using nonlinear finite element numerical simulation. Collision performance of LNG carrier and collision indicators during the collision, the impact force, velocity and displacement and energy absorption in the process of collision by changing parameters of the major velocity, impact angle and impact location and others are studied. The relevant research results have a strong practical significance for analyzing the deformation, strengthening measures and structural repair of ship side structure impact damage.

Impact Damage Resistance of CFRP Prepreg Laminates with Dispersed CSP Particles into Ply Interfaces

2011 ◽  
Vol 21 (8) ◽  
pp. 1106-1127 ◽  
Author(s):  
Mubarak Ali ◽  
Sunil C. Joshi
Keyword(s):  
Energy Absorption ◽  
Impact Damage ◽  
Peak Load ◽  
Damage Mechanism ◽  
Impact Response ◽  
Sem Images ◽  
Initial Severity ◽  
Extent Of Damage ◽  
Energy Absorbing ◽  
The Impact

The effects of incorporating core shell polymer (CSP) particles within interply interfaces on the impact response of CFRP prepreg laminates are investigated. The impact tests were conducted on samples without and with CSP particles into the ply interfaces. The loads versus time curves were examined to determine the impact response and the associated energy absorption by the laminates were studied. The results indicate that both, the peak load of the laminates improved by 41% and damping index (DI) reduced by 90% with the dispersion of 51 g/m2 of CSP particles within the prepreg ply interfaces of the laminates. It was noted that the CSP particles shielded the composites from the initial severity of impact. The energy absorbing mechanisms altered the supercritical response of the laminate to subcritical due to increase in the elastic energy stored within the laminates with CSP particles thereby changing the energy absorption modes. It was observed from macroscopic observations and SEM images of the damage sites that the damage mechanism and patterns changed and the extent of damage reduced with the addition of CSP particles.

scholarly journals Hygrothermal Ageing Influence on BVI-Damaged Carbon/Epoxy Coupons under Compression Load

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2038
Author(s):  
Maria Pia Falaschetti ◽  
Matteo Scafé ◽  
Nicola Zavatta ◽  
Enrico Troiani
Keyword(s):  
Residual Strength ◽  
Impact Damage ◽  
Mechanical Analysis ◽  
Test Method ◽  
Combined Loading ◽  
Compression Load ◽  
Impact Location ◽  
Hygrothermal Ageing ◽  
Influence Of Water ◽  
Compressive Tests

Composite materials usage in several industrial fields is now widespread, and this leads to the necessity of overcoming issues that are still currently open. In the aeronautic industry, this is especially true for Barely Visible Impact Damage (BVID) and humidity uptake issues. BVID is the most insidious kind of impact damage, being rather common and not easily detectable. These, along with the ageing that a composite structure could face during its operative life, could be a cause of fatal failures. In this paper, the influence of water absorption on impacted specimens compressive residual strength was studied. Specimens were impacted using a modified Charpy pendulum. Two different locations were chosen for comparison: Near-Edge (NE) and Central (CI). Accelerated hygrothermal ageing was conducted on impacted and reference nonimpacted coupons, placing them in a water-filled jar at 70 °C. Compressive tests were performed in accordance with the Combined Loading Compression (CLC) test method. A Dynamic Mechanical Analysis (DMA) was performed as well. The results showed the influence of hygrothermal ageing, as expected. Nevertheless, the influence of impact location on compressive residual strength is not clearly noticeable in aged specimens, leading to the conclusion that hygrothermal ageing may have a greater effect on composite compressive strength than the analysed BVI damage.

Sign in / Sign up

Export Citation Format

Share Document