scholarly journals Investigations on Air and Underwater Blast Mitigation in Polymeric Composite Structures- A Review

2021 ◽  
pp. 113530
Author(s):  
Piyush Wanchoo ◽  
Helio Matos ◽  
Carl-Ernst Rousseau ◽  
Arun Shukla
Author(s):  
Ajay Kesavan ◽  
Sabu John ◽  
Henry Li ◽  
Israel Herszberg

This paper introduces the some of the experimental and analytical work behind the autonomous damage detection technique. The research study conducted here resulted in the development of a Structural Health Monitoring (SHM) system for a 2-D polymeric composite T-joint, used in maritime structures. Two methods of damage detection are discussed — A statistics-based outlier technique and one using Artificial Neural Networks (ANNs). The SHM using ANNs system was found to be capable of not only detecting the presence of multiple delaminations in a composite structure, but also capable of determining the location and extent of all the delaminations present in the T-joint structure, regardless of the load (angle and magnitude) acting on the structure. The system developed relies on the examination of the strain distribution of the structure under operational loading. Finally, on testing the SHM system developed with strain signatures of composite T-joint structures, subjected to variable loading, embedded with all possible damage configurations (including multiple damage scenarios), an overall damage (location & extent) prediction accuracy of 94.1% was achieved. These results are presented and discussed in detail in this paper.


2012 ◽  
Vol 24 (8) ◽  
pp. 991-1006 ◽  
Author(s):  
Oliver J Myers ◽  
George Currie ◽  
Jonathan Rudd ◽  
Dustin Spayde ◽  
Nydeia Wright Bolden

Defects in composite laminates are difficult to detect because of the conductive and paramagnetic properties of composite materials. Timely detection of defects in composite laminates can improve reliability. This research illustrates the preliminary analysis and detection of delaminations in carbon fiber laminate beams using a single layer of magnetostrictive particles and noncontacting concentric magnetic excitation and sensing coils. The baseline analytical models also begin to address the intrusive nature of the magnetostrictive particles as well as relate the applied excitation field with the stress and magnetic flux densities induced in the magnetostrictive layer. Numerical methods are used to begin to characterize the presence of magnetostrictive particles in the laminate and the behavior of the magnetostrictive particles in relationship to the magnetic field used during sensing. Unidirectional laminates with embedded delaminations are used for simulations and experimentations. A novel, yet simplified fabrication method is discussed to ensure consistent scanning and sensing capabilities. The nondestructive evaluation scanning experiments were conducted with various shapes and sizes of damages introduced into carbon fiber–reinforced polymeric composite structures. The results demonstrate high potential for magnetostrictive particles as a low-cost, noncontacting, and reliable sensor for nondestructive evaluation of composite materials.


2018 ◽  
Vol 923 ◽  
pp. 13-16 ◽  
Author(s):  
Salvatore Saputo ◽  
Angela Russo ◽  
Antonio Raimondo ◽  
Barbara Iodice ◽  
Mauro Zarrelli

The fire behaviour of Polymeric composite structures is one of the most critical aerospace research topics. Indeed, the exposure of Polymeric composite structures to high temperatures leads to material decomposition, associated to thermal and mechanical properties degradation. This degradation causes a reduction of the mechanical performances, which can be of main concern for safety reasons. In this paper, the tensile behaviour of Carbon Fibre Composite Polymer specimens, subjected to fire, has been experimentally and numerically investigated. The material properties degradation has been estimated according to an Arrhenius shape function, which relates the mechanical properties of the composite to the temperature. At first, static structural analyses have been carried out to assess the mechanical behaviour of the investigated specimen without fire effects. Then, a coupled thermo-structural analysis allowed evaluating the fire effect on the specimens’ mechanical and the thermal behaviour. In order to preliminary validate the proposed degradation model, the numerical results, in terms of Load versus Displacements curves, have been compared against data obtained from an ad-hoc experimental campaign where fire condition have been suitably replicated during the mechanical tests.


2021 ◽  
Vol 2021 (4) ◽  
pp. 25-32
Author(s):  
Irina Zlobina

The results of three-point bend comparative tests of carbon and glass-fiber samples checked and treated in the MWF electromagnetic field after external environment factor impact in the course of eight months are shown. It is defined that the modification of carbon fiber in a hardened state in the MWF electromagnetic field decreases a negative impact of external environment of strength decrease after eight-month exposure by 44.3…73%, glass-fiber – by 6%. The MWF treatment is offered as a finishing technological operation at manufacturing polymeric composite design elements.


Sign in / Sign up

Export Citation Format

Share Document