Comparison between Non-Destructive Evaluation Techniques and Integrated Fiber Optic Health Monitoring Systems for Composite Sandwich Structures

2000 ◽  
Vol 11 (6) ◽  
pp. 426-437
Author(s):  
D. Balageas ◽  
S. Bourasseau ◽  
M. Dupont ◽  
E. Bocherens ◽  
V. Dewynter-Marty ◽  
...  
Keyword(s):  
Health Monitoring ◽  
Fiber Optic ◽  
Sandwich Structures ◽  
Monitoring Systems ◽  
Composite Sandwich ◽  
Composite Sandwich Structures ◽  
Non Destructive Evaluation ◽  
Health Monitoring Systems ◽  
Non Destructive ◽  
Evaluation Techniques

A Vibro Acoustic Method for Non Destructive Test of Composite Sandwich Structures

2015 ◽  
Vol 751 ◽  
pp. 153-158 ◽  
Author(s):  
Márcio H. de Avelar Gomes ◽  
Paulo R.O. Bonifácio ◽  
Mário O.M. de Carvalho ◽  
Hilbeth Parente Azikri de Deus
Keyword(s):  
Sandwich Structures ◽  
Acoustic Method ◽  
Adhesive Tape ◽  
Acoustic Response ◽  
Composite Sandwich ◽  
Impulsive Excitation ◽  
Composite Sandwich Structures ◽  
Deconvolution Technique ◽  
Failure Map ◽  
Non Destructive

The present work describes an investigation into a vibro-acoustic method to check the existence of superficial flaws in composite sandwich structures, based in a technique inspired in the well known Tap Test. In this case, however, a non-impulsive excitation is provided by an especial transducer and the acoustic response is captured with a microphone. A deconvolution technique is used in order to assess the system's impulse response and generate a “failure” map after post-processing the results. Post-processed parameters evaluated are: Loudness, Sharpness and a discrepancy indicator for the transfer function (named TFDI). Results suggest that Loudness and TFDI potentially indicate the existence of a damaged core and the lack of adhesive tape.

scholarly journals Non-destructive Methods for Damage Assessment of Composite Sandwich Structures

2018 ◽  
Vol 188 ◽  
pp. 01008 ◽  
Author(s):  
Petr Bělský ◽  
Martin Kadlec
Keyword(s):  
Sandwich Structures ◽  
Test Results ◽  
Composite Sandwich ◽  
Core Damage ◽  
Composite Sandwich Structures ◽  
Ultrasonic Techniques ◽  
Detection Capabilities ◽  
Non Destructive ◽  
Laser Shearography ◽  
Impact Damages

Sandwich structures are capable of absorbing large amounts of energy under impact loads which results in high structural crashworthiness. Comparison of detection capabilities of selected C-scan NDT methods applicable for inspections of sandwich structures was performed using water-squirt, air-coupled and pitch-catch ultrasonic techniques, supplemented by laser shearography. Test results have shown that water-squirt and pitch-catch techniques are the most suitable methods for the core damage evaluation. Air-coupled method showed lower sensitive for detection of some artificial defects and impact damages in honeycomb sandwiches when unfocused transducers were used. The combination of the presented methods was able to reveal most of the defects.

scholarly journals The energy absorption behavior of novel composite sandwich structures reinforced with trapezoidal latticed webs

2021 ◽  
Vol 60 (1) ◽  
pp. 503-518
Author(s):  
Juan Han ◽  
Lu Zhu ◽  
Hai Fang ◽  
Jian Wang ◽  
Peng Wu
Keyword(s):  
Bearing Capacity ◽  
Energy Absorption ◽  
Sandwich Structure ◽  
Ultimate Load ◽  
Sandwich Structures ◽  
Elastic Displacement ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Composite Sandwich ◽  
Composite Sandwich Structures

Abstract This article proposed an innovative composite sandwich structure reinforced with trapezoidal latticed webs with angles of 45°, 60° and 75°. Four specimens were conducted according to quasi-static compression methods to investigate the compressive behavior of the novel composite structures. The experimental results indicated that the specimen with 45° trapezoidal latticed webs showed the most excellent energy absorption ability, which was about 2.5 times of the structures with vertical latticed webs. Compared to the traditional composite sandwich structure, the elastic displacement and ultimate load-bearing capacity of the specimen with 45° trapezoidal latticed webs were increased by 624.1 and 439.8%, respectively. Numerical analysis of the composite sandwich structures was carried out by using a nonlinear explicit finite element (FE) software ANSYS/LS-DYNA. The influence of the thickness of face sheets, lattice webs and foam density on the elastic ultimate load-bearing capacity, the elastic displacement and initial stiffness was analyzed. This innovative composite bumper device for bridge pier protection against ship collision was simulated to verify its performance. The results showed that the peak impact force of the composite anti-collision device with 45° trapezoidal latticed webs would be reduced by 17.3%, and the time duration will be prolonged by about 31.1%.

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