scholarly journals Experimental tests and numerical simulations of ballistic impact on laminated glass

2021 ◽  
Vol 250 ◽  
pp. 02022
Author(s):  
Karoline Osnes ◽  
Jens Kristian Holmen ◽  
Tormod Grue ◽  
Tore Børvik
Keyword(s):  
Numerical Simulations ◽  
Numerical Study ◽  
Glass Plate ◽  
Experimental Tests ◽  
Ballistic Impact ◽  
Laminated Glass ◽  
Glass Pane ◽  
Numerical Predictions ◽  
Node Splitting ◽  
Glass Plates

In this study, we investigate double-laminated glass plates under ballistic impact through experimental tests and numerical simulations. The experimental tests are used to determine the ballistic limit velocity and curve for the laminated glass targets, and to create a basis for comparison with numerical simulations. We tested two different glass pane configurations: (1) one double-laminated glass plate, and (2) two layers of double-laminated glass plates separated by an airgap. In the numerical study, we used finite element simulations that employed higher order elements and 3D node splitting to predict the residual velocities of the bullets in the experiments. Node splitting enabled modelling of fracture by element separation and was employed for the glass parts. The material and fracture models that we used for the glass and the PVB parts were simplified, but the numerical predictions proved to be in excellent agreement with the experimental results.

scholarly journals Simulation Study of Low-Velocity Impact on Polyvinyl Butyral Laminated Glass Based on the Combined TCK-JH2 Model

2019 ◽  
Vol 9 (15) ◽  
pp. 3204
Author(s):  
Wei ◽  
Li ◽  
Zhang
Keyword(s):  
Experimental Tests ◽  
Polyvinyl Butyral ◽  
Low Velocity Impact ◽  
Glass Layer ◽  
Laminated Glass ◽  
Low Velocity ◽  
Glass Pane ◽  
Low Speed ◽  
Rate Dependent ◽  
Annealed Glass

In this paper, both experimental tests and numerical simulations of Polyvinyl Butyral (PVB) laminated glass pane under low-speed impact were carried out. In order to accurately predict the responses of annealed glass under low-speed impact, a constitutive model combined of the Taylor–Chen–Kuszmaul (TCK) model and the Johnson-Holmquist Ceramic (JH2) model is proposed. In order to describe the tensile damage characteristic of annealed glass, a rate-dependent TCK model is employed. The JH2 model is adopted when the glass material is under compression. The velocity and force of impactor, deflection of central point of glass pane, and the cracking pattern are studied to verify the combined TCK-JH2 model. Furthermore, the effects of the thickness of glass layer and PVB interlayer are investigated.

Experimental and Numerical Study in Denting Resistance of 6111-T4 Aluminium Alloy

2006 ◽  
Vol 519-521 ◽  
pp. 889-894 ◽  
Author(s):  
Nuno Peixinho ◽  
António Pinho
Keyword(s):  
Constitutive Equation ◽  
Numerical Simulations ◽  
Aluminium Alloy ◽  
Numerical Study ◽  
Experimental Tests ◽  
Experimental Results ◽  
Dynamic Effects ◽  
Circular Area ◽  
Thick Plates ◽  
Automotive Panels

This study presents results of denting resistance of 6111-T4 aluminium alloy. Experimental results of dynamic denting were compared with numerical simulations performed using LS-DYNA software. The experimental tests were performed on 1mm thick plates clamped in a circular area with a diameter of 80mm. Dynamic denting was accomplished by dropping different indenters from heights ranging from 0.36 to 1.7 m. The obtained results indicate a high suitability of the aluminium alloy for use in automotive panels. The results of the numerical simulations display a good correlation with experiments if dynamic effects are introduced in the constitutive equation of the material through the Cowper-Symonds coefficients.

scholarly journals A Feasibility Study for Using Fishnet to Protect Offshore Wind Turbine Monopile Foundations from Damage by Scouring

2019 ◽  
Vol 9 (23) ◽  
pp. 5023 ◽  
Author(s):  
Bo Yang ◽  
Kexiang Wei ◽  
Wenxian Yang ◽  
Tieying Li ◽  
Bo Qin ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Wind Turbine ◽  
Laboratory Tests ◽  
Numerical Study ◽  
Experimental Tests ◽  
Cost Effective ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Effective Measure ◽  
Flow Coupling

Offshore wind turbine monopile foundations are subjected to complex wind, wave, and flow coupling effects, which result in seabed scouring around the monopile. The consequent scour pits threaten the reliability, safety, and load-carrying capacity of the monopile. In order to develop a cost-effective measure to mitigate such an issue, a new countermeasure device, named “fishnet”, is studied in this paper using a combined approach of numerical simulations and experimental tests. In the research, the size of the fishnet, diameter of the fishnet thread, and the installation height of the fishnet were optimized in order to achieve the best protection to the monopile foundation. In the paper, both numerical simulations and laboratory tests proved the effectiveness of the proposed “fishnet” in reducing the scour around the wind turbine monopile foundations. Moreover, its contribution to erosion reduction can be further enhanced via optimization. It was found that, after optimization, the maximum shear force on the seabed could be reduced by 14% in the numerical study, and the maximum depth of the scour pit could be reduced by 38.2% in laboratory tests.

Using Ansys for Design and Numerical Study of a Specific Fixed Wing UAV

2018 ◽  
Vol 55 (4) ◽  
pp. 652-657 ◽  
Author(s):  
Gabriel Murariu ◽  
Razvan Adrian Mahu ◽  
Adrian Gabriel Murariu ◽  
Mihai Daniel Dragu ◽  
Lucian P. Georgescu ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Unmanned Aerial Vehicle ◽  
Numerical Study ◽  
Flight Time ◽  
Cluster System ◽  
Numerical Results ◽  
Operational Performance ◽  
Gliding Flight ◽  
Aerial Vehicle ◽  
Constant Altitude

This article presents the design of a specific unmanned aerial vehicle UAV prototype own building. Our UAV is a flying wing type and is able to take off with a little boost. This system happily combines some major advantages taken from planes namely the ability to fly horizontal, at a constant altitude and of course, the great advantage of a long flight-time. The aerodynamic models presented in this paper are optimized to improve the operational performance of this aerial vehicle, especially in terms of stability and the possibility of a long gliding flight-time. Both aspects are very important for the increasing of the goals� efficiency and for the getting work jobs. The presented simulations were obtained using ANSYS 13 installed on our university� cluster system. In a next step the numerical results will be compared with those during experimental flights. This paper presents the main results obtained from numerical simulations and the obtained magnitudes of the main flight coefficients.

scholarly journals Impact Fracture and Fragmentation of Glass via the 3D Combined Finite-Discrete Element Method

2021 ◽  
Vol 11 (6) ◽  
pp. 2484
Author(s):  
Zhou Lei ◽  
Esteban Rougier ◽  
Earl E. Knight ◽  
Mengyan Zang ◽  
Antonio Munjiza
Keyword(s):  
Discrete Element Method ◽  
Automobile Industry ◽  
Glass Plate ◽  
Discrete Element ◽  
Impact Fracture ◽  
Constitutive Relationship ◽  
Laminated Glass ◽  
Fracture Patterns ◽  
Fracture Processes ◽  
Element Method

A driving technical concern for the automobile industry is their assurance that developed windshield products meet Federal safety standards. Besides conducting innumerable glass breakage experiments, product developers also have the option of utilizing numerical approaches that can provide further insight into glass impact breakage, fracture, and fragmentation. The combined finite-discrete element method (FDEM) is one such tool and was used in this study to investigate 3D impact glass fracture processes. To enable this analysis, a generalized traction-separation model, which defines the constitutive relationship between the traction and separation in FDEM cohesive zone models, was introduced. The mechanical responses of a laminated glass and a glass plate under impact were then analyzed. For laminated glass, an impact fracture process was investigated and results were compared against corresponding experiments. Correspondingly, two glass plate impact fracture patterns, i.e., concentric fractures and radial fractures, were simulated. The results show that for both cases, FDEM simulated fracture processes and fracture patterns are in good agreement with the experimental observations. The work demonstrates that FDEM is an effective tool for modeling of fracture and fragmentation in glass.

scholarly journals AC Current Ripple in Three-Phase Four-Leg PWM Converters with Neutral Line Inductor

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1430
Author(s):  
Aleksandr Viatkin ◽  
Riccardo Mandrioli ◽  
Manel Hammami ◽  
Mattia Ricco ◽  
Gabriele Grandi
Keyword(s):  
Numerical Simulations ◽  
Pulse Width Modulation ◽  
Neutral Line ◽  
Experimental Tests ◽  
Performance Comparison ◽  
Design Parameters ◽  
Switching Frequency ◽  
Three Phase ◽  
Ac Current ◽  
Current Ripple

This paper presents a comprehensive study of peak-to-peak and root-mean-square (RMS) values of AC current ripples with balanced and unbalanced fundamental currents in a generic case of three-phase four-leg converters with uncoupled AC interface inductors present in all three phases and in neutral. The AC current ripple characteristics were determined for both phase and neutral currents, considering the sinusoidal pulse-width modulation (SPWM) method. The derived expressions are simple, effective, and ready for accurate AC current ripple calculations in three- or four-leg converters. This is particularly handy in the converter design process, since there is no need for heavy numerical simulations to determine an optimal set of design parameters, such as switching frequency and line inductances, based on the grid code or load restrictions in terms of AC current ripple. Particular attention has been paid to the performance comparison between the conventional three-phase three-leg converter and its four-leg counterpart, with distinct line inductance values in the neutral wire. In addition to that, a design example was performed to demonstrate the power of the derived equations. Numerical simulations and extensive experimental tests were thoroughly verified the analytical developments.

Experimental and Numerical Investigation on the Influence of Process Speed on the Blanking Process

2002 ◽  
Vol 124 (2) ◽  
pp. 416-419 ◽  
Author(s):  
A. M. Goijaerts ◽  
L. E. Govaert ◽  
F. P. T. Baaijens
Keyword(s):  
Stainless Steel ◽  
Constitutive Model ◽  
Numerical Simulations ◽  
Ferritic Stainless Steel ◽  
Fracture Criterion ◽  
Fracture Initiation ◽  
Rate Dependence ◽  
Numerical Predictions ◽  
Punch Velocity ◽  
Blanking Process

In a previous work a numerical tool was presented which accurately predicted both process force and fracture initiation for blanking of a ferritic stainless steel in various blanking geometries. This approach was based on the finite element method, employing a rate-independent elasto-plastic constitutive model combined with a fracture criterion which accounts for the complete loading history. In the present investigation this work is extended with respect to rate-dependence by employing an elasto-viscoplastic constitutive model in combination with the previously postulated fracture criterion for ferritic stainless steel. Numerical predictions are compared to experimental data over a large range of process speeds. The rate-dependence of the process force is significant and accurately captured by the numerical simulations at speeds ranging from 0.001 to 10 mm/s. Both experiments and numerical simulations show no influence of punch velocity on fracture initiation.

Experimental and Numerical Study of Methanol-Water Mixture Single-Phase Heat Transfer in a Micro-Channel Heat Sink

2012 ◽  
Author(s):  
Chun K. Kwok ◽  
Matthew M. Asada ◽  
Jonathan R. Mita ◽  
Weilin Qu
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Heat Sink ◽  
Single Phase ◽  
Numerical Study ◽  
Pure Water ◽  
Molar Fraction ◽  
Water Mixture ◽  
Micro Channel ◽  
Numerical Predictions

This paper presents an experimental study of single-phase heat transfer characteristics of binary methanol-water mixtures in a micro-channel heat sink containing an array of 22 microchannels with 240μm × 630μm cross-section. Pure water, pure methanol, and five methanol-water mixtures with methanol molar fraction of 16%, 36%, 50%, 63% and 82% were tested. Key parametric trends were identified and discussed. The experimental study was complemented by a three-dimensional numerical simulation. Numerical predictions and experimental data are in good agreement with a mean absolute error (MAE) of 0.87%.

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