Depth Profiling of Polymer Composites by Ultrafast Laser Ablation

2009 ◽  
Author(s):  
Christopher N. Young ◽  
Clive R. Clayton ◽  
Jon P. Longtin ◽  
Richard D. Granata
Keyword(s):  
Laser Ablation ◽  
Depth Profiling ◽  
Femtosecond Laser Ablation ◽  
Ablation Rate ◽  
Fiber Reinforced Polymer ◽  
Heterogeneous Distribution ◽  
Reinforced Polymer ◽  
Before And After ◽  
Fluence Regime ◽  
Ablation Property

Past work has shown femtosecond laser ablation to be a non-thermal process at low fluences in polymer systems. The ablation rate in this low fluence regime is very low, allowing for micro-scale removal of material. We have taken advantage of this fact to perform shallow depth profiling ablation on carbon fiber reinforced polymer (CFRP) composites. Neat resin and composite samples were studied to establish reference ablation profiles. These profiles and the effects of the heterogeneous distribution of carbon fibers were observed through optical and scanning electron microscopy. Weathered materials that have been subjected to accelerated tests in artificial sunlight or high temperature conditions were ablated to evaluate any correlation between exposure and change in ablation characteristics. Preliminary Raman and micro-ATR analysis performed before and after ablation shows no chemical changes indicative of thermal effects. The low-volume-ablation property was utilized in an attempt to expose the sizing-matrix interphase for analysis.

scholarly journals Seismic Retrofitting of Traditional Masonry with Pultruded FRP Profiles

2020 ◽  
Vol 10 (7) ◽  
pp. 2489 ◽  
Author(s):  
Francesca Sciarretta
Keyword(s):  
Maximum Load ◽  
Seismic Retrofitting ◽  
Fiber Reinforced Polymer ◽  
Experimental Program ◽  
Future Research ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Before And After ◽  
Basic Frame

This paper presents a study on the potentiality of seismic retrofitting solutions with pultruded Fiber Reinforced Polymer (FRP) profiles. This material can be used in connected frames providing lightweight, corrosion-free and reversible retrofitting of masonry buildings with the moderate requirements of surface preservation. In a hypothetical case study, an experimental program was designed; monotonic shear tests on a half-size physical model of the sample wall were performed to assess the structural performance before and after retrofitting with a basic frame of pultruded Glass Fiber Reinforced Polymer (GFRP) C-shaped profiles, connected to the masonry by steel threaded bar connections. During the tests, the drift, the diagonal displacements in the masonry and the micro-strain in the profiles were measured. The retrofitted system has proven very effective in delaying crack appearance, increasing the maximum load (+85% to +93%) and ultimate displacement (up to +303%). The failure mode switches from rocking to a combination of diagonal cracking and bed joint sliding. The gauge recordings show a very limited mechanical exploitation of the GFRP material, despite the noticeable effectiveness of the retrofit. The application seems thus promising and worth a deeper research focus. Finally, a finite element modelling approach has been developed and validated, and it will be useful to envisage the effects of the proposed solution in future research.

Cure Monitoring of Composites Based on Embedded Fiber Bragg Gratings

2011 ◽  
Vol 211-212 ◽  
pp. 585-589 ◽  
Author(s):  
Xiao Yan Shen
Keyword(s):  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Cure Process ◽  
Cfrp Laminates ◽  
Cure Monitoring ◽  
Fbg Sensor ◽  
Reinforced Polymer ◽  
Before And After ◽  
Fbg Sensors ◽  
The Difference

Cure-induced strain is produced inevitably during the fabrication of the composite. To measure the strain, undamaged methods such as using fiber Bragg grating(FBG) sensor are employed. In this paper, nine unidirectional carbon fiber-reinforced polymer(CFRP) laminates are autoclaved produced, with FBGs embedded in different layers through the thickness (0-layer, 5-layer, 10-layer and 13-layer). The experiment measures the difference of the FBGs’ Bragg wavelengths before and after the cure which is linearly relevant to the cure-induced strain, to explore the distribution of strains through the thickness. The experimental results indicate a certain strain in neural plane of approximately 370με under the designed size of the laminates. The results also show that the cure-induced strains in different layers through the thickness are less than 1000με even including all errors, however they do not display distinct regular in thickness direction. Moreover, through the FBG sensors and the thermocouples, the cure process with the strain and temperature variations is understood well. The result verifies that the cure-induced strain is mainly generated at the end of the cure when the temperature cools down.

Towards femtosecond laser ablation ionization mass spectrometric approaches for chemical depth-profiling analysis of lead-free Sn solder bumps with minimized side-wall contributions

2018 ◽  
Vol 33 (2) ◽  
pp. 283-293 ◽  
Author(s):  
A. Cedeño López ◽  
V. Grimaudo ◽  
P. Moreno-García ◽  
A. Riedo ◽  
M. Tulej ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Depth Profiling ◽  
Side Wall ◽  
Femtosecond Laser Ablation ◽  
Mass Spectrometric ◽  
Lead Free ◽  
Ionization Mass ◽  
Organic Impurities ◽  
Solder Bumps ◽  
Profiling Analysis

Sn solder bumps on Cu pillars and the quantification of incorporated organic impurities are of urgent interest to the microchip industry.

scholarly journals Femtosecond laser ablation of brass: A study of surface morphology and ablation rate

2012 ◽  
Vol 30 (3) ◽  
pp. 473-479 ◽  
Author(s):  
Mohamed E. Shaheen ◽  
Brian J. Fryer
Keyword(s):  
Laser Ablation ◽  
Femtosecond Laser ◽  
Surface Morphology ◽  
Fine Particles ◽  
Femtosecond Laser Ablation ◽  
Laser Pulses ◽  
Ambient Air ◽  
Ablation Rate ◽  
Femtosecond Laser Pulses ◽  
Nanosecond Laser

AbstractThe interaction of near infrared femtosecond laser pulses with a Cu based alloy (brass) in ambient air at atmospheric pressure and under different laser conditions was investigated. The effects of laser fluence and number of pulses on surface morphology and ablation rate were studied using scanning electron microscopy (SEM) and optical microscopy. Ablation rates were found to rapidly increase from 83 to 604 nm/pulse in the fluence range 1.14–12.21 J/cm2. At fluence >12.21 J/cm2, ablation rates increased slowly to a maximum (607 nm/pulse at 19.14 J/cm2), and then decreased at fluence higher than 20.47 J/cm2 to 564 nm/pulse at 24.89 J/cm2. Large amounts of ablated material in a form of agglomerated fine particles were observed around the ablation craters as the number of laser pulses and fluence increased. The study of surface morphology shows reduced thermal effects with femtosecond laser ablation in comparison to nanosecond laser ablation at low fluence.

Depth profiling of multi-layer samples using femtosecond laser ablation

2001 ◽  
Vol 16 (6) ◽  
pp. 616-621 ◽  
Author(s):  
V. Margetic ◽  
M. Bolshov ◽  
A. Stockhaus ◽  
K. Niemax ◽  
R. Hergenröder
Keyword(s):  
Laser Ablation ◽  
Femtosecond Laser ◽  
Depth Profiling ◽  
Femtosecond Laser Ablation

Analytical study on torsional behavior of concrete beams strengthened with fiber reinforced polymer laminates using softened truss model

2020 ◽  
pp. 136943322098169
Author(s):  
Muhanad M Majed ◽  
Mohammadreza Tavakkolizadeh ◽  
Abbas A Allawi
Keyword(s):  
Analytical Model ◽  
Computational Procedure ◽  
Fiber Reinforced Polymer ◽  
Rc Beams ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Truss Model ◽  
Torsional Behavior ◽  
Before And After ◽  
Polymer Laminates

This study aimed at evaluating the torsional capacity of reinforced concrete (RC) beams externally wrapped with fiber reinforced polymer (FRP) materials. An analytical model was described and used as a new computational procedure based on the softened truss model (STM) to predict the torsional behavior of RC beams strengthened with FRP. The proposed analytical model was validated with the existing experimental data for rectangular sections strengthened with FRP materials and considering torque-twist relationship and crack pattern at failure. The confined concrete behavior, in the case of FRP wrapping, was considered in the constitutive laws of concrete in the model. Then, an efficient algorithm was developed in MATLAB environment to accomplish the analysis, solve the appropriate equations, and calculate the torsional moment and angle of twist at all points. The parametric study considered the effect of effective fiber strain to reach a better prediction for the full torsional behavior. The model was able to predict the torsional behavior of the RC beams strengthened with FRP materials before and after cracking stages with reasonable accuracy.

On the use of femtosecond laser ablation to facilitate spectroscopic depth profiling of heterogeneous polymeric coatings

2005 ◽  
Vol 89 (3) ◽  
pp. 393-409 ◽  
Author(s):  
Lionel T. Keene ◽  
Thomas Fiero ◽  
Clive R. Clayton ◽  
Gary P. Halada ◽  
David Cardoza ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Femtosecond Laser ◽  
Depth Profiling ◽  
Femtosecond Laser Ablation ◽  
Polymeric Coatings
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