scholarly journals Experimental and Numerical Impact Analysis of Automotive Bumper Brackets Made of 2D Triaxially Braided CFRP Composites

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3554
Author(s):  
Robert Böhm ◽  
Andreas Hornig ◽  
Tony Weber ◽  
Bernd Grüber ◽  
Maik Gude
Keyword(s):  
High Speed ◽  
Impact Analysis ◽  
Damage Model ◽  
Drop Tower ◽  
Structural Deformation ◽  
Impact Behavior ◽  
Speed Test ◽  
Damage Models ◽  
The Impact ◽  
Carbon Fiber Epoxy

The impact behavior of carbon fiber epoxy bumper brackets reinforced with 2D biaxial and 2D triaxial braids was experimentally and numerically analyzed. For this purpose, a phenomenological damage model was modified and implemented as a user material in ABAQUS. It was hypothesized that all input parameters could be determined from a suitable high-speed test program. Therefore, novel impact test device was designed, developed and integrated into a drop tower. Drop tower tests with different impactor masses and impact velocities at different bumper bracket configurations were conducted to compare the numerically predicted deformation and damage behavior with experimental evidence. Good correlations between simulations and tests were found, both for the global structural deformation, including fracture, and local damage entities in the impact zone. It was proven that the developed phenomenological damage models can be fully applied for present-day industrial problems.

Experimental Calibration of ISV Damage Model Constants for Pure Copper for High-Speed Impact Simulation

2016 ◽  
Author(s):  
Yangqing Dou ◽  
Yucheng Liu ◽  
Wilburn Whittington ◽  
Jonathan Miller
Keyword(s):  
High Speed ◽  
Impact Analysis ◽  
Split Hopkinson Pressure Bar ◽  
Internal State ◽  
Pure Copper ◽  
Damage Model ◽  
Hopkinson Pressure Bar ◽  
Experimental Calibration ◽  
High Speed Impact ◽  
The Impact

Coefficients and constants of a microstructure-based internal state variable (ISV) plasticity damage model for pure copper have been calibrated and used for damage modeling and simulation. Experimental stress-strain curves obtained from Cu samples at different strain rate and temperature levels provide a benchmark for the calibration work. Instron quasi-static tester and split-Hopkinson pressure bar are used to obtain low-to-high strain rates. Calibration process and techniques are described in this paper. The calibrated material model is used for high-speed impact analysis to predict the impact properties of Cu. In the numerical impact scenario, a 100 mm by 100 mm Cu plate with a thickness of 10 mm will be penetrated by a 50 mm-long Ni rod with a diameter of 10mm. The thickness of 10 mm was selected for the Cu plate so that the Ni-Cu penetration through the thickness can be well observed through the simulations and the effects of the ductility of Cu on its plasticity deformation during the penetration can be displayed. Also, that thickness had been used by some researchers when investigating penetration mechanics of other materials. Therefore the penetration resistance of Cu can be compared to that of other metallic materials based on the simulation results obtained from this study. Through this study, the efficiency of this ISV model in simulating high-speed impact process is verified. Functions and roles of each of material constant in that model are also demonstrated.

Diamond-Like Carbon Coating—It'S Application for Polymeric Substrates

1991 ◽  
Vol 239 ◽  
Author(s):  
Fred M. Kimock ◽  
Alex J. Hsieh ◽  
Peter G. Dehmer ◽  
Pearl W. Yip
Keyword(s):  
High Speed ◽  
Protective Coatings ◽  
Ion Beam ◽  
Chemical Exposure ◽  
Optical Systems ◽  
Impact Behavior ◽  
Organic Liquids ◽  
Diamond Like Carbon ◽  
Dlc Coating ◽  
The Impact

ABSTRACTWe report on a recently commercialized Diamond-Like Carbon (DLC) coating that has been deposited on polycarbonate at near room temperature, via a unique ion beam system. Aspects of high speed impact behavior, chemical resistance, abrasion resistance, and thermal stability of the coating are examined. Results of scanning electron microscopy studies indicate that adhesion of the DLC coating is very good; no delamination of the coating was found on ballistically tested specimens. The well-bonded DLC coating did not cause the impact performance of polycarbonate to become brittle. Chemical exposure test results show that the DLC coating is capable of protecting polycarbonate from chemical attack by aggressive organic liquids. These ion beam deposited DLC coatings have considerable potential as protective coatings for optical systems.

scholarly journals Experimental and Analytical Characterization of Drop Impact Behavior for a Mobile Haptic Actuator

2017 ◽  
Author(s):  
Byungjoo Choi ◽  
Jiwoon Kwon ◽  
Yongho Jeon ◽  
Moon Gu Lee
Keyword(s):  
High Speed ◽  
Damping Ratio ◽  
Free Fall ◽  
Element Model ◽  
Impact Behavior ◽  
Air Resistance ◽  
Impact Reliability ◽  
The Impact ◽  
The Finite Element Model

Impact characterization of linear resonant actuator (LRA) is studied experimentally by newly developed drop tester, which can control various experimental uncertainty such as rotational moment, air resistance, secondary impact and so on. The feasibility of this test apparatus was verified by comparison with free fall test. By utilizing a high-speed camera and measuring the vibrational displacement of spring material, the impact behavior was captured and the damping ratio of the system was defined. Based on the above processes, the finite element model was established and the experimental and analytical results were successfully correlated. Finally, the damage of the system from impact loading can be expected by developed model and as a result, this research can improve the impact reliability of LRA.

Numerical Modeling of Hydrodynamic Impact and Local Slamming Effects

2015 ◽  
Author(s):  
Ali Mohtat ◽  
Ravi Challa ◽  
Solomon C. Yim ◽  
Carolyn Q. Judge
Keyword(s):  
Numerical Method ◽  
Impact Velocity ◽  
High Speed ◽  
Impact Behavior ◽  
Analytical Prediction ◽  
Arbitrary Lagrangian Eulerian ◽  
Hydrodynamic Impact ◽  
Ale Formulation ◽  
Wide Range ◽  
The Impact

Numerical simulation and prediction of short duration hydrodynamic impact loading on a generic wedge impacting a water free-surface is investigated. The fluid field is modeled using a finite element (FE) based arbitrary Lagrangian-Eulerian (ALE) formulation and the structure is modeled using a standard Lagrangian FE approximation. Validation of the numerical method against experimental test data and closed form analytical solutions shows that the ALE-FE/FE continuum approach captures the impact behavior accurately. A detailed sensitivity analysis is conducted to study the role of air compressibility, deadrise angle, and impact velocity in estimation of maximum impact pressures. The pressure field is found to be insensitive to air compressibility effect for a wide range of impact velocities and deadrise angles. A semi-analytical prediction model is developed for estimation of maximum impact pressures that correlates deadrise angle, impact velocity, and a nonlinear interaction term that couples hydrodynamic effects between these parameters. The numerical method is also used to examine the intrinsic physics of water impact on a high-speed planing hull with the goal of predicting slamming loads and resulting motions.

A High Pressure-Short Time Shear Strength Analyzer for Lubricants

1985 ◽  
Vol 107 (2) ◽  
pp. 220-223 ◽  
Author(s):  
B. Jacobson
Keyword(s):  
High Pressure ◽  
Shear Strength ◽  
High Speed ◽  
Maximum Pressure ◽  
Strength Increase ◽  
Transient Pressure ◽  
Static Tests ◽  
Speed Test ◽  
Short Time ◽  
The Impact

High pressure rheology of lubricants under transient pressure and shear stress loads is studied experimentally. The total compression time is about 140 μs and the maximum pressure during the impact time is 5.5 GPa. The results from this high speed test apparatus agree well with static tests of the shear strength increase with pressure up to 2.2 GPa.

Investigation of the Impact Analysis of Microscale Thin-Walled Structures Manufactured by High-Speed Machining

2006 ◽  
Vol 326-328 ◽  
pp. 1599-1602
Author(s):  
Bo Sung Shin
Keyword(s):  
Finite Element ◽  
Cutting Force ◽  
High Speed ◽  
Impact Analysis ◽  
Thin Wall ◽  
High Speed Machining ◽  
High Speed Cutting ◽  
Thin Walled Structures ◽  
Thin Walled ◽  
The Impact

High-speed machining (HSM) is very useful method as one of the most effective manufacturing processes because it has excellent quality and dimensional accuracy for precision machining. Recently micromachining technologies of various functional materials with very thin walls are needed in the field of electronics, mobile telecommunication and semiconductors. However, HSM is not suitable for microscale thin-walled structures because of the lack of their structure stiffness to resist high-speed cutting force. A microscale thin wall machined by HSM shows the characteristics of the impact behavior because the high-speed cutting force works very shortly on the machined surface. We propose impact analysis model in order to predict the limit thickness of a very thin-wall and investigate its limit thickness of thin-wall manufactured by HSM using finite element method. Also, in order to verify the usefulness of this method, we will compare finite element analyses with experimental results and demonstrate some applications.

SUMMARY OF STUDIES OF COREXIT DISPERSANT DROPLET IMPACT BEHAVIOR INTO OIL SLICKS AND DISPERSANT DROPLET EVAPORATION1,2

2008 ◽  
Vol 2008 (1) ◽  
pp. 797-800 ◽  
Author(s):  
Timothy A. Ebert ◽  
Roger Downer ◽  
James Clark ◽  
Charles A. Huber
Keyword(s):  
High Speed ◽  
Impact Analysis ◽  
Droplet Impact ◽  
Impact Behavior ◽  
Oil Slick ◽  
Corexit 9500 ◽  
Droplet Sizes ◽  
Evaporative Loss ◽  
Pass Through ◽  
Oil Films

ABSTRACT This paper presents the results of two related studies concerning the aerial application of dispersants. The first study characterized the interactions of various sized Corexit 9500 and 9527 dispersant droplets with oil films of from 0.1 mm to 3.0 mm thickness. A film thickness of 0.1 mm was selected as the end point since this is the thinnest oil film recommended for the application of dispersants. The results of the high speed video droplet impact analysis showed that droplet diameters of 1,000 microns will not pass through an oil slick of 0.1 mm and mix with the underlying water column and that slick thickness of 0.2 mm or more will prevent even 2,000 micron diameter droplets from passing through the slick. These droplet sizes are considerably larger than the current ASTM Standard recommended droplet size of 300–500 microns for dispersant application. Additionally, it was shown that droplets that do pass through an oil slick will in whole or in part rise back up to the oil water interface. The second study characterized and compared the evaporation rates of Corexit 9500 and 9527 droplets with water over a 20 minute period under varying conditions of humidity and temperature. Under high evaporative conditions of high temperature (90° F) and low humidity (40%), droplets ranging from 0.25 to 1 uL showed 2–10% evaporative loss for Corexit 9500, 28–35% evaporative loss for Corexit 9527, and complete evaporative loss for water. When tested at low evaporative conditions of low temperature (40° F) and high humidity (95%), no evaporative loss was recorded for droplets of either 9500 or 9527, and water lost 18%.

scholarly journals Analysis of metal transfer and weld geometry in hot-wire GTAW with indirect resistive heating

2020 ◽  
Vol 64 (12) ◽  
pp. 2109-2117
Author(s):  
T. Ungethüm ◽  
E. Spaniol ◽  
M. Hertel ◽  
U. Füssel
Keyword(s):  
High Speed ◽  
Impact Analysis ◽  
Metal Transfer ◽  
Hot Wire ◽  
Melt Pool ◽  
Gtaw Process ◽  
The Wire ◽  
Wire Feeding ◽  
Data Acquisition Unit ◽  
The Impact

Abstract In this publication, the different metal transfer modes of a hot-wire GTAW process with indirect resistive preheating of the wire are presented. The hot-wire GTAW process is characterized by an additional preheating unit that is used to heat the wire before it reaches the melt pool. Thus, to preheat the wire, the contact between the melt pool and the wire is not necessary. In order to examine the metal transfer of the wire, deposition welds are analysed using a high-speed camera with a laser light source as well as a data acquisition unit. The presented results comprise the impact analysis of the GTAW current, the hot-wire current, the wire feeding rate, the wire feeding angle as well as the wire feeding direction. The observed metal transfer modes can be characterized as either a constant melting bridge (cmb) between the wire and the melt pool or a recurring melting bridge (rmb). The analysis also reveals that the influence of the process parameters and thus the metal transfer mode on the bead properties is only marginal.

Low Velocity Impact Analysis on GFRP Laminates under Different Temperatures

2011 ◽  
Vol 110-116 ◽  
pp. 632-636
Author(s):  
K. Pazhanivel ◽  
G.B. Bhaskar ◽  
S. Arunachalam ◽  
V. Hariharan ◽  
A. Elayaperumal
Keyword(s):  
Composite Materials ◽  
Impact Analysis ◽  
Failure Modes ◽  
Laminated Composites ◽  
Low Velocity Impact ◽  
Impact Behavior ◽  
Low Velocity ◽  
Aerospace Applications ◽  
Different Temperatures ◽  
The Impact

Composite materials have a number of properties that make them attractive for use in aerospace applications. The impact behavior of fiber reinforced composite materials is much more complex than conventional metallic structures due to a number of different failure modes on the inter laminar and intra laminar level. The aim of this study is to investigate the effects of temperature and thermal residual stresses on the impact behavior and damage of glass/epoxy laminated composites. To this end, thermal stress analyses of the laminates with lay-ups [90/0/0/90] s, [90/0/45/45] s, [0/90/45/-45] s, [45/0/-45/90] s are carried out under different temperatures by using ANSYS software. Also, the impact analysis on the laminated composites was performed at the different range of impact energies under different temperatures. The specific energy values and impact parameters were obtained and compared for each type of specimens and temperatures.

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