Experimental testing and numerical simulation of a temporary rescue bridge using GFRP composite materials

2016 ◽  
Vol 114 ◽  
pp. 181-193 ◽  
Author(s):  
Hsiao-Hui Hung ◽  
Yu-Chi Sung ◽  
Kou-Chun Chang ◽  
Shih-Hsun Yin ◽  
Fang-Yao Yeh
Keyword(s):  
Numerical Simulation ◽  
Composite Materials ◽  
Experimental Testing ◽  
Gfrp Composite

scholarly journals Experimental Study of Plasma Plume Analysis of Long Pulse Laser Irradiates CFRP and GFRP Composite Materials

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 545
Author(s):  
Yao Ma ◽  
Chao Xin ◽  
Wei Zhang ◽  
Guangyong Jin
Keyword(s):  
Composite Materials ◽  
Laser Processing ◽  
Plasma Plume ◽  
Material Surface ◽  
Laser Fabrication ◽  
Breakdown Time ◽  
Reinforced Polymer ◽  
Gfrp Composite ◽  
Damage Process ◽  
Long Pulse

The application of laser fabrication of fiber-reinforced polymer (FRP) has an irreplaceable advantage. However, the effect of the plasma generated in laser fabrication on the damage process is rarely mentioned. In order to further study the law and mechanism of laser processing, the laser process was measured. CFRP and GFRP materials were damaged by a 1064 nm millisecond pulsed laser. Moreover, the propagation velocity and breakdown time of plasma plume were compared. The results show that GFRP is more vulnerable to breakdown than CFRP under the same conditions. In addition, the variation of plasma plume and material surface temperature with the number of pulses was also studied. The results show that the variation trend is correlated, that is, the singularities occur at the second pulse. Based on the analysis of experimental phenomena, this paper provides guidance for plasma phenomena in laser processing of composite materials.

Numerical Simulation Study on Thermal-Hydraulic Performances of Vehicular Radiator Heat Transfer Units

2012 ◽  
Vol 538-541 ◽  
pp. 2061-2066
Author(s):  
Yang Zheng ◽  
Bao Lan Xiao ◽  
Wei Ming Wu ◽  
Xiao Li Yu ◽  
Guo Dong Lu
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Cooling System ◽  
Experimental Testing ◽  
Orthogonal Experiment ◽  
Simulation Method ◽  
Manufacturing Cost ◽  
Performance Simulation ◽  
Factor Study ◽  
Testing Cost

A radiator is one of the most important components in vehicular cooling system whose excellent fluid flow and heat transfer characteristics guarantees the engine operations. The calculation workload for performance simulation of a whole radiator is too huge due to its size. Experimental study is the conventional method to study radiator performance. This paper put forward a numerical simulation method and radiator heat transfer units were taken as study objects. Orthogonal experiment method was adopted to arrange multi-factor and multi-level calculation schemes. 23 samples with different fin parameters were simulated to investigate their thermal-hydraulic performances. Compared with experimental testing, this method greatly reduced sample manufacturing cost and testing cost, and offered data support for the effect factor study of radiator heat transfer units.

Design of an Air-Cooled Radial Turbine: Part 1 — Computational Modelling

2018 ◽  
Author(s):  
Yang Zhang ◽  
Tomasz Duda ◽  
James A. Scobie ◽  
Carl M. Sangan ◽  
Colin D. Copeland ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Experimental Testing ◽  
Temperature Drop ◽  
Computational Modelling ◽  
Operating Conditions ◽  
Inlet Temperature ◽  
Topology Optimisation ◽  
Internal Cooling ◽  
Element Analysis ◽  
Radial Turbine

This paper is part of a two-part publication that aims to design, simulate and test an internally air cooled radial turbine. To achieve this, the additive manufacturing process, Selective Laser Melting (SLM), was utilized to allow internal cooling passages within the blades and hub. This is, to the authors’ knowledge, the first publication in the open literature to demonstrate an SLM manufactured, cooled concept applied to a small radial turbine. In this paper, the internally cooled radial turbine was investigated using a Conjugate Heat Transfer (CHT) numerical simulation. Topology Optimisation was also implemented to understand the areas of the wheel that could be used safely for cooling. In addition, the aerodynamic loss and efficiency of the design was compared to a baseline non-cooled wheel. The experimental work is detailed in Part 2 of this two-part publication. Given that the aim was to test the rotor under representative operating conditions, the material properties were provided by the SLM technology collaborator. The boundary conditions for the numerical simulation were derived from the experimental testing where the inlet temperature was set to 1023 K. A polyhedral unstructured mesh made the meshing of internal coolant plenums including the detailed supporting structures possible. The simulation demonstrated that the highest temperature at the blade leading edge was 117 K lower than the uncooled turbine. The coolant mass flow required by turbine was 2.5% of the mainstream flow to achieve this temperature drop. The inertia of the turbine was also reduced by 20% due to the removal of mass required for the internal coolant plenums. The fluid fields in both the coolant channels and downstream of the cooled rotor were analyzed to determine the aerodynamic influence on the temperature distribution. Furthermore, the solid stress distribution inside the rotor was analyzed using Finite Element Analysis (FEA) coupled with the CFD results.

Experimental Testing Conducted in the Course of the GIPIPE Project and Their Numerical Simulation

2020 ◽  
pp. 51-87
Author(s):  
Spyros A. Karamanos ◽  
Sjors H. J. van Es ◽  
Angelos Tsatsis ◽  
Gregory C. Sarvanis ◽  
Polynikis Vazouras ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Experimental Testing

Comparative Studies on the Cutting Performance of CVD Diamond and DLC Coated Inserts in Turning GFRP Composite Materials

2010 ◽  
Vol 431-432 ◽  
pp. 466-469
Author(s):  
Dong Can Zhang ◽  
Bin Shen ◽  
Fang Hong Sun ◽  
Ming Chen ◽  
Zhi Ming Zhang
Keyword(s):  
Composite Materials ◽  
Flank Wear ◽  
Arc Discharge ◽  
Cutting Tools ◽  
Chemical Vapor ◽  
Cvd Diamond ◽  
Cutting Performance ◽  
Vacuum Arc ◽  
Reinforced Plastics ◽  
Gfrp Composite

The diamond and diamond-like carbon (DLC) films were deposited on the cobalt cemented tungsten carbide (WC-Co) cutting tools respectively adopting the hot filament chemical vapor deposition (HFCVD) technique and the vacuum arc discharge with a graphite cathode. The scanning electron microscope (SEM), X-ray diffraction spectroscopy (XRD) and Raman spectroscopy were used to characterize the as-deposited diamond and DLC films. To evaluate their cutting performance, comparative turning tests were conducted using the uncoated WC-Co and as-fabricated CVD diamond and DLC coated inserts, with glass fiber reinforced plastics (GFRP) composite materials as the workpiece. The research results exhibited that diamond and DLC coated inserts had great advantages in cutting tests compared to uncoated insert. The flank wear of the CVD diamond coated insert maintained a very low value about 50μm before the cutting tool failure occurred. For the DLC coated insert, its flank wear always maintained a nearly constant value of 70~200μm during whole 45 minutes turning process. The flank wear of CVD diamond coated insert was lower than that of DLC coated insert before diamond films peeling off.

scholarly journals Damage detection in laminar thermoplastic composite materials by means of embedded optical fibers

2006 ◽  
Vol 60 (7-8) ◽  
pp. 176-179
Author(s):  
Aleksandar Kojovic ◽  
Irena Zivkovic ◽  
Ljiljana Brajovic ◽  
Dragan Mitrakovic ◽  
Radoslav Aleksic
Keyword(s):  
Composite Materials ◽  
Optical Fiber ◽  
Real Time ◽  
Optical Fibers ◽  
Impact Damage ◽  
Experimental Testing ◽  
Low Energy ◽  
Thermoplastic Composite ◽  
Woven Fabric ◽  
The Impact

This paper investigates the possibility of applying optical fibers as sensors for investigating low energy impact damage in laminar thermoplastic composite materials, in real time. Impact toughness testing by a Charpy impact pendulum with different loads was conducted in order to determine the method for comparative measurement of the resulting damage in the material. For that purpose intensity-based optical fibers were built in to specimens of composite materials with Kevlar 129 (the DuPont registered trade-mark for poly(p-phenylene terephthalamide)) woven fabric as reinforcement and thermoplastic PVB (poly(vinyl butyral)) as the matrix. In some specimens part of the layers of Kevlar was replaced with metal mesh (50% or 33% of the layers). Experimental testing was conducted in order to observe and analyze the response of the material under multiple low-energy impacts. Light from the light-emitting diode (LED) was launched to the embedded optical fiber and was propagated to the phototransistor-based photo detector. During each impact, the signal level, which is proportional to the light intensity in the optical fiber, drops and then slowly recovers. The obtained signals were analyzed to determine the appropriate method for real time damage monitoring. The major part of the damage occurs during impact. The damage reflects as a local, temporary release of strain in the optical fiber and an increase of the signal level. The obtained results show that intensity-based optical fibers could be used for measuring the damage in laminar thermoplastic composite materials. The acquired optical fiber signals depend on the type of material, but the same set of rules (relatively different, depending on the type of material) could be specified. Using real time measurement of the signal during impact and appropriate analysis enables quantitative evaluation of the impact damage in the material. Existing methods in most cases use just the intensity of the signal before and after the impact, as the measure of damage. This method could be used to monitor the damage in real time, giving warnings before fatal damage occurs.

Wideband microstrip dual polarization radiator for X-band APAA

2021 ◽  
Author(s):  
P.L. Batov ◽  
E.N. Gurkin ◽  
S.O. Knyazev ◽  
D.L. Borisevitch
Keyword(s):  
Numerical Simulation ◽  
Antenna Arrays ◽  
Experimental Testing ◽  
Test Sample ◽  
Phased Antenna Arrays ◽  
X Band ◽  
Sample Testing ◽  
Simulation Results ◽  
Gain Loss ◽  
Decoupling Coefficient

In this paper the model and the construction of a wideband microstrip X-band radiator of active phased antenna arrays have been presented. The basic demands to the radiator have been formulated. The results of computer electromagnetic simulation of the radiator in free space and in the infinite array have been given, as well as the results of radiator experimental testing in the waveguide simulator. The characteristics of a proposed radiator such as VSWR, decoupling coefficient and losses have been simulated and estimated experimentally on the test sample. Experiment has shown good agreement with numerical simulation results. Particularly, 20% bandwidth with VSWR no greater than 2 has been achieved. Sample testing in a waveguide simulator gives 0,5 dB loss (active and return loss in radiator without loss in simulator itself). Scan angle at 3 dB gain loss, as it follows from numerical simulation results, should be no less than ±40° or ±45° in the main planes. So, proposed microstrip radiator may be used for X-band active phased arrays, which should work in 20% bandwidth with steerable polarization.

Deflection Analysis of Sleeve Jointed Purlin Systems with Non-Linear Rotational Stiffness

2011 ◽  
Vol 147 ◽  
pp. 66-69 ◽  
Author(s):  
Chang J. Wang ◽  
Diane J. Mynors ◽  
Tertia Morgan ◽  
Brian Cartwright
Keyword(s):  
Numerical Simulation ◽  
Linear Relationship ◽  
Experimental Testing ◽  
Rotational Stiffness ◽  
Non Linear ◽  
Deflection Analysis

Sleeved purlin systems are usually used in roof constructions. A non-linear relationship between the bolt hole extension and the load transferred to the bolt was derived with experimental testing and numerical simulation. Consequently, the non-linear rotational stiffness of sleeved joints was derived based on the configuration of sleeves in this paper. The procedure for calculating the deflection of purlin systems with non-linear rotational stiffness at the joints is presented. The analysis and calculation of the deflection is demonstrated through a case study.

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