scholarly journals Ultrasonic guided wave-based debond identification in a GFRP plate with L-stiffener

2021 ◽  
Author(s):  
Kaleeswaran Balasubramaniam ◽  
Shirsendu Sikdar ◽  
Tomasz Wandowski ◽  
Pawel M Malinowski
Keyword(s):  
Laser Doppler Vibrometer ◽  
Guided Wave ◽  
Composite Panel ◽  
Size Estimation ◽  
Ultrasonic Guided Wave ◽  
Point Analysis ◽  
Glass Fibre Reinforced Polymer ◽  
Depth Analysis ◽  
Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced

Abstract This paper presents a robust assessment of debond in a glass fibre-reinforced polymer composite structure with L-stiffener attachment. Towards this, the ultrasonic guided wave (GW) propagation based laboratory experiments have been carried out on a stiffened composite panel with piezoelectric transducers (PZT) for the excitation of GWs and a scanning laser Doppler vibrometer (SLDV) for sensing the GW propagation. To study the changes caused by the stiffener and debond a signal processing based multi-point analysis has been carried out. The proposed methodology consists of two steps. Step 1 using the full wavefield root mean square energy map-based approach to check the presence of debond. Step 2 using point-wise measurements to study debond localization and size estimation using a baseline free signal coefficient difference algorithm (SCDA). The proposed processing approaches are applied for an in-depth analysis of the experimental signals that provide information about the interaction of GWs with stiffener and debond. The mentioned approaches take advantage of the asymmetry caused by the damage. For the applied SCDA methodology there is no need for full-wavefield measurements, healthy case measurements, as only a few measurement points can be enough for the assessment of stiffener debond in such structures.

scholarly journals Thermal Delamination Modelling and Evaluation of Aluminium–Glass Fibre-Reinforced Polymer Hybrid

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 492
Author(s):  
Zhen Pei Chow ◽  
Zaini Ahmad ◽  
King Jye Wong ◽  
Seyed Saeid Rahimian Koloor ◽  
Michal Petrů
Keyword(s):  
Crack Front ◽  
Cohesive Zone ◽  
Experimental Tests ◽  
Mode I ◽  
Mode Ii ◽  
Cohesive Model ◽  
Reinforced Polymer ◽  
Glass Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced

This paper aims to propose a temperature-dependent cohesive model to predict the delamination of dissimilar metal–composite material hybrid under Mode-I and Mode-II delamination. Commercial nonlinear finite element (FE) code LS-DYNA was used to simulate the material and cohesive model of hybrid aluminium–glass fibre-reinforced polymer (GFRP) laminate. For an accurate representation of the Mode-I and Mode-II delamination between aluminium and GFRP laminates, cohesive zone modelling with bilinear traction separation law was implemented. Cohesive zone properties at different temperatures were obtained by applying trends of experimental results from double cantilever beam and end notched flexural tests. Results from experimental tests were compared with simulation results at 30, 70 and 110 °C to verify the validity of the model. Mode-I and Mode-II FE models compared to experimental tests show a good correlation of 5.73% and 7.26% discrepancy, respectively. Crack front stress distribution at 30 °C is characterised by a smooth gradual decrease in Mode-I stress from the centre to the edge of the specimen. At 70 °C, the entire crack front reaches the maximum Mode-I stress with the exception of much lower stress build-up at the specimen’s edge. On the other hand, the Mode-II stress increases progressively from the centre to the edge at 30 °C. At 70 °C, uniform low stress is built up along the crack front with the exception of significantly higher stress concentrated only at the free edge. At 110 °C, the stress distribution for both modes transforms back to the similar profile, as observed in the 30 °C case.

Ultimate capacity of barrier–deck anchorage in MTQ TL-5 barrier reinforced with headed-end, high-modulus, sand-coated GFRP bars

2018 ◽  
Vol 45 (4) ◽  
pp. 263-278 ◽  
Author(s):  
Michael Rostami ◽  
Khaled Sennah ◽  
Hamdy M. Afefy
Keyword(s):  
Highway Bridges ◽  
Experimental Program ◽  
Embedment Depth ◽  
Reinforced Polymer ◽  
Vehicle Impact ◽  
Glass Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced ◽  
Experimental Findings ◽  
Deck Slab

This paper presents an experimental program to justify the barrier design at the barrier–deck junction when compared to the factored applied transverse vehicular loading specified in the Canadian Highway Bridge Design Code (CHBDC). Compared to the dimensioning and the glass fibre reinforced polymer (GFRP) bar detailing of a recently crash-tested GFRP-reinforced barrier, the adopted barrier configurations in this paper were similar to those specified by Ministry of Transportation of Québec (MTQ) for TL-5 barrier except that the base of the barrier was 40 mm narrower and the deck slab is of 200 mm thickness, leading to reduction in the GFRP embedment depth into the deck slab. Four full-scale TL-5 barrier specimens were tested to collapse. Correlation between the experimental findings and the factored applied moments from CHBDC equivalent vehicle impact forces resulting from the finite-element modelling of the barrier–deck system was conducted followed by recommendations for use of the proposed design in highway bridges in Québec.

scholarly journals The Effect of Layers and Bullet Type on Impact Properties of Glass Fibre Reinforced Polymer (GFRP) Using a Single Stage Gas Gun (SSGG)

2014 ◽  
Vol 564 ◽  
pp. 428-433 ◽  
Author(s):  
S.N.A. Safri ◽  
Mohamed Thariq Hameed Sultan ◽  
N. Razali ◽  
Shahnor Basri ◽  
Noorfaizal Yidris ◽  
...  
Keyword(s):  
Impact Energy ◽  
Glass Fibre ◽  
Impact Test ◽  
Single Stage ◽  
Gas Gun ◽  
Reinforced Polymer ◽  
Glass Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced ◽  
The Impact

The purpose of this work is to study the best number of layer with the higher impact energy using Glass Fibre Reinforced Polymer (GFRP). The number of layers used in this study was 25, 33, 41, and 49. The impact test was performed using Single Stage Gas Gun (SSGG) for each layers given above with different bullets such as blunt, hemispherical and conical bullets. The gas gun pressure was set to 5, 10, 15 and 20 bar. All of the signals captured from the impact test were recorded using a ballistic data acquisition system. The correlation between the impact energy in terms of number of layer and type of bullet from this test are presented and discussed. It can be summarise that as the number of layer increases, impact energy also increases. In addition, from the results, it was observed that by using different types of bullets (blunt, hemispherical, conical), there is only a slight difference in values of energy absorbed by the specimen.

Quasi-Static Indentation Behaviour of Glass Fibre Reinforced Polymer

2014 ◽  
Vol 970 ◽  
pp. 317-319 ◽  
Author(s):  
Syed Mohd Saiful Azwan ◽  
Yahya Mohd Yazid ◽  
Ayob Amran ◽  
Behzad Abdi
Keyword(s):  
Glass Fibre ◽  
Polyester Resin ◽  
Loading Rates ◽  
Reinforced Polymer ◽  
Glass Fibre Reinforced Polymer ◽  
Static Indentation ◽  
Indentation Tests ◽  
Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced ◽  
Chopped Strand Mat

Fibre reinforced polymer (FRP) plates subject to quasi-static indentation loading were studied. The plates were fabricated from three layers of chopped strand mat glass fibre and polyester resin using vacuum infusion process. Indentation tests were conducted on the plates with loading rates of 1 mm/min, 10 mm/min, 100 mm/min and 500 mm/min using a hemispherical tip indenter with diameter 12.5 mm. The plates were clamped in a square fixture with an unsupported space of 100 mm × 100 mm. The loads and deflections at the indented location were measured to give energy absorption-deflection curves. The results showed that the loading rate has a large effect on the indentation behaviour and energy absorbed.

Effect of Flexural Static Load on the Strength of GFRP Gratings

2014 ◽  
Vol 567 ◽  
pp. 387-392
Author(s):  
Amir Izzuddin ◽  
Ibrisam Akbar
Keyword(s):  
Glass Fibre ◽  
Vinyl Ester ◽  
Static Load ◽  
Weight Ratio ◽  
Water Area ◽  
High Resistivity ◽  
Glass Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced ◽  
Deep Water Area

– The usage of steel in offshore deep water area contributes to the massive load of the offshore platform which will lead to the massive operational cost. Therefore, the reduction of weight of platform is the major issue that need to be tackled properly. The great improvement in strength to weight ratio compare to steel and high resistivity to corrosion makes Glass Fibre Reinforced Polymer (GFRP) grating preferable. GFRP gratings are normally made of two types of processes which are moulded and pultruded and it is usually consists of glass fibre and bonding matrixes of vinyl ester (VE), polyester (PE), or phenolic (PHE). However there is still doubt on GFRP grating application for offshore due to no consensus guidelines for the design of GFRP grating and there are many several types of GFRP grating available to be chosen. This paper presenting the study on two types of GFRP grating strength with variation of bonding matrixes under flexural static load. A total of six specimens of GFRP grating which consist of 1 each of molded vinyl ester, molded polyester, molded phenolic, pultruded vinyl ester, pultruded polyester and pultruded phenolic were tested to failure in flexure. The main parameters concerns in this study are 1) max load vs. mid-span deflection and 2) failure mode of the specimens.

Sign in / Sign up

Export Citation Format

Share Document