Response Surface Approach for Sensitivity Study of Neck Forces in Restrained Child Occupant during Side-Impact Crash

2014 ◽  
Vol 575 ◽  
pp. 477-480
Author(s):  
S. Shasthri ◽  
V. Kausalyah ◽  
Q. Shah ◽  
Kassim A. Abdullah ◽  
Moumen Idres ◽  
...  
Keyword(s):  
Response Surface ◽  
Latin Hypercube Sampling ◽  
Sensitivity Study ◽  
Impact Angle ◽  
Side Impact ◽  
Surface Approach ◽  
Critical Range ◽  
Impact Angles ◽  
Child Occupant ◽  
The Impact

A study is undertaken to characterize the Neck Force (NF) of a CRS restrained 3 year old child occupant involved in lateral and oblique side impact. The Response Surface Method is used to map the parameter sensitivity upon the NF for impact speed of 32.2 km/h (20 mph) both individually as well as cross interactively. Design of Experiments is used with Latin Hypercube Sampling involving six predictors. A study of the response plots and statistical data obtained provide insights on the characteristic of each predictor with respect to the neck forces sustained. Greater parameter significance affecting neck forces is seen for narrow impact angles (φ ≤ 60°). Singularly, the impact angle parameter is revealed to be largely the most sensitive parameter to affect neck force especially at narrow angles. The critical range for this is identified to be between angles 50° and 70° while a secondary critical range is observed for angles below 34°.

scholarly journals Neck Moment Characterization of Restrained Child Occupant at Realistic Nontest Standard Higher Impact Speed of 32.2 km/h

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
S. Shasthri ◽  
V. Kausalyah ◽  
Qasim H. Shah ◽  
Kassim A. Abdullah ◽  
Moumen M. Idres ◽  
...  
Keyword(s):  
Interactive Effect ◽  
Impact Angle ◽  
Side Impact ◽  
Impact Speed ◽  
Child Restraint ◽  
Child Restraint System ◽  
Impact Angles ◽  
Child Occupant ◽  
The Impact

The effects of bullet vehicle crash impact angle, child restraint system design, and restraint harness slack at side impact speed of 32.2 km/h (20 mph) on moments sustained at the neck by a three-year-old child are investigated. Mathematical models are built using the response surface method based on simulation results whereby good fitness is achieved. The singular and cross interactive effect of each predictor on the neck moment are analyzed. The number of significant parameters affecting the neck moment is shown to be the largest for wide impact angles (ϕ≥60°) and the impact angle parameter is largely revealed to be the most sensitive. An ideal safe range for low neck moment has been established to be within ϕ angles 45° and 65°. It is further shown that the nature of all parameters effect on the neck moment is highly dependent on the impact angle range.

scholarly journals The effect of heat treatment and impact angle on the erosion behavior of nickel-tungsten carbide cold spray coating using response surface methodology

2021 ◽  
Author(s):  
Marios Kazasidis ◽  
Elisa Verna ◽  
Shuo Yin ◽  
Rocco Lupoi
Keyword(s):  
Heat Treatment ◽  
Response Surface Methodology ◽  
Mass Loss ◽  
Tungsten Carbide ◽  
Response Surface ◽  
Spray Coating ◽  
Impact Angle ◽  
Control Factors ◽  
Heat Treated ◽  
The Impact

AbstractThis study elucidates the performance of cold-sprayed tungsten carbide-nickel coating against solid particle impingement erosion using alumina (corundum) particles. After the coating fabrication, part of the specimens followed two different annealing heat treatment cycles with peak temperatures of 600 °C and 800 °C. The coatings were examined in terms of microstructure in the as-sprayed (AS) and the two heat-treated conditions (HT1, HT2). Subsequently, the erosion tests were carried out using design of experiments with two control factors and two replicate measurements in each case. The effect of the heat treatment on the mass loss of the coatings was investigated at the three levels (AS, HT1, HT2), as well as the impact angle of the erodents (30°, 60°, 90°). Finally, the response surface methodology (RSM) was applied to analyze and optimize the results, building the mathematical models that relate the significant variables and their interactions to the output response (mass loss) for each coating condition. The obtained results demonstrated that erosion minimization was achieved when the coating was heat treated at 600 °C and the angle was 90°.

Erosion-Abrasion Behavior of Eutectic Al-Mn Alloy Matrix Composites Reinforced with Al2O3 Particulates

2010 ◽  
Vol 152-153 ◽  
pp. 1054-1057
Author(s):  
Bing Liu ◽  
Xin Mei Li ◽  
Xiang Liu ◽  
Chun Yao Wang
Keyword(s):  
Solid Solution ◽  
Shear Stress ◽  
Impact Angle ◽  
Matrix Composites ◽  
Alloy Matrix ◽  
Abrasion Test ◽  
Wear Rates ◽  
Impact Angles ◽  
The Impact ◽  
Worn Surface

Effects of different impact angles such as 45°and 90°on the erosion-abrasion properties of eutectic Al-Mn alloy and its composites reinforced with Al2O3 particulates were studied by rotating erosion-abrasion test, and the microstructure and the worn surfaces were analyzed. The results show that the as-cast Al-Mn alloy is composed of aluminium-manganese solid solution, MnAl6 and Al11Mn4 phase, while the δ-Al2O3 particles are included in the composites besides the aforementioned microstructures. With elongating the erosion time, the wear rates of the Al-Mn alloy and its composites increase at the impact angle of 90°, whereas they firstly increase and then decrease , and there is a maximum at 45°. The distortion wear caused by the normal stress is dominant at 90°, which lead to the erosion pits on the worn surface. However, the cutting wear by the shear stress is predominant at 45°, which result in the ploughs.

Stepwise Erosion as a Method for Investigating the Wear Mechanisms at Different Impact Angles in Slurry Erosion

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Y. M. Abd-Elrhman ◽  
A. Abouel-Kasem ◽  
S. M. Ahmed ◽  
K. M. Emara
Keyword(s):  
Rebound Effect ◽  
Impact Angle ◽  
Silica Sand ◽  
Slurry Erosion ◽  
Nominal Size ◽  
Erosion Mechanisms ◽  
Impact Angles ◽  
The Impact ◽  
Calculated Number ◽  
Number Of Particles

In the present work, stepwise erosion technique was carried out to investigate in detail the influence of impact angle on the erosion process of AISI 5117 steel. The number of impact sites and their morphologies at different impact angles were investigated using scanning electron microscope (SEM) examination and image analysis. The tests were carried out with particle concentration of 1 wt. %, and the impact velocity of slurry stream was 15 m/s. Silica sand—which has a nominal size range of 250–355 μm—was used as an erodent, using whirling-arm test rig. The results have shown that the number of craters, as expected, increases with the increase in the mass of erodent for all impact angles and this number decreases with the increase of the impact angle. In addition, the counted number of craters is larger than the calculated number of particles at any stage for all impact angles. This may be explained by the effect of the rebound effect of particles, the irregular shape for these particles, and particle fragmentation. The effect of impact angle based on the impact crater shape can be divided into two regions; the first region for θ ≤ 60 deg and the second region for θ ≥ 75 deg. The shape of the craters is related to the dominant erosion mechanisms of plowing and microcutting in the first region and indentation and lip extrusion in the second region. In the first region, the length of the tracks decreases with the increase of impact angle. The calculated size ranges are from few micrometers to 100 μm for the first region and to 50 μm in the second region. Chipping of the former impact sites by subsequent impact particles plays an important role in developing erosion.

Crashworthiness Simulation Analysis of Light Sport Aircraft Fuselage Structure

2011 ◽  
Vol 199-200 ◽  
pp. 48-53 ◽  
Author(s):  
Pu Woei Chen ◽  
Shu Han Chang ◽  
Yu Yang Hsieh ◽  
Tai Sing Sun
Keyword(s):  
Simulation Analysis ◽  
Impact Angle ◽  
General Aviation ◽  
Aviation Industry ◽  
Aircraft Fuselage ◽  
Passenger Safety ◽  
Engine Mount ◽  
Distance Travel ◽  
Impact Angles ◽  
The Impact

In recent years, light sport aircraft, which not only serve the purpose of personal recreation but also act as a means of transportation for medium and short distance travel, have rapidly gained popularity in the general aviation industry worldwide. The FAA established regulations for this new category of airplanes in 2004. However, the crashworthiness requirements for this type of airplane have not been clearly specified. This study used the finite element method to investigate the effect of the impact angle and speed of the LSA fuselage structure on passenger safety during a crash event. We used sink speed defined by NASA AGATE, ASTM and FAR as parameters. The passenger compartment reducing rate defined by MIL-STD-1290A was used for a safety boundary condition. The results show that the maximum cockpit reducing rate of the airplane impact angle is 30o. When the impact angle increases, owing to the engine mount and fire wall’s reinforced structure, this type of airplane can sustain a greater vertical drop speed. When the impact angle is about 80°~90°, the maximum impact speed the fuselage that can be sustained is 33 m/s. This work also completed a simulation of safe and unsafe ranges for light sport aircraft at various impact angles and vertical drop speeds during impact.

scholarly journals Impact and Ricochet of a High Speed Projectile from a Plate

2021 ◽  
Vol 71 (6) ◽  
pp. 737-747
Author(s):  
Hussein Bassindowa ◽  
Bakhtier Farouk ◽  
Steven B. Segletes
Keyword(s):  
Titanium Alloy ◽  
High Speed ◽  
Computational Study ◽  
Incident Angle ◽  
Finite Thickness ◽  
Impact Angle ◽  
Projectile Velocity ◽  
Alloy Plate ◽  
Impact Angles ◽  
The Impact

A computational study of a projectile (either 2024 aluminum or TiAl6V4 titanium alloy) impacting a plate (either titanium alloy or aluminum) is presented in this paper. Projectile velocity (ranging from 250 m/s to 1500 m/s) with varying impact angles are considered. The presence of ricochet (if any) is identified over the ranges of the projectile velocity and impact angle considered. For the cases where ricochet is identified, the ricochet angle and velocity are predicted as functions of the incident angle and the incident velocity. The numerical results are compared with an analytical solution of the ricochet problem. The analytical solutions are from a model developed to predict the ballistic ricochet of a projectile (projectile) penetrator. The dynamics and the deformation of an aluminum (or a titanium alloy) projectile impacting on a finite thickness titanium alloy (or aluminum) plate are simulated. The current work is interesting in that it looks in the field of ballistics of different material combinations than are traditionally studied. The present simulations based on detailed material models for the aluminum and the titanium alloy and the impact physics modelling features in the LS-DYNA code provide interesting details regarding the projectile/plate deformations and post-impact projectile shape and geometry. The present results indicate that for no cases (for specified incoming velocities and impact angles considered) can an aluminum projectile penetrate a titanium alloy plate. The ricochet ‘mode predictions ‘obtained from the present simulations agree well with the ricochet ‘mode predictions’ given in an analytical model.

scholarly journals Design of experiment in analyzing uncertainty of simulation results in accident reconstruction

2018 ◽  
Vol 233 (4) ◽  
pp. 836-850 ◽  
Author(s):  
Tiefang Zou ◽  
Hua Li ◽  
Hequan Wu ◽  
Lin Hu ◽  
Ming Cai
Keyword(s):  
Response Surface ◽  
Design Of Experiment ◽  
Orthogonal Design ◽  
Uniform Design ◽  
Latin Hypercube Sampling ◽  
Surface Model ◽  
Accident Reconstruction ◽  
Pedestrian Accident ◽  
The Impact ◽  
Accident Case

In order to obtain a more accurate interval of an accident reconstruction result, two modified experiment design methods were proposed. The first is based on the orthogonal design (OD) and it is named as the orthogonal-based design (OBD), while the other is based on the uniform design (UD) and it is named as the multi-response surface-uniform design (MUD). Furthermore, some conclusions are given according to seven numerical cases: results obtained from the Latin hypercube sampling design (LHS) are the worst, while those obtained from the UD are the last but one, and all are worse than the results obtained from the OBD and the MUD. Furthermore, some conclusions about the number of simulation runs of each design of experiment (DOE) can be given: if the second order response surface model is selected, the number of simulation runs of the LHS is the same as the UD, and all are lesser than the number of simulation runs of the OBD and the MUD in most cases. As for the OBD and the MUD, the number of simulation runs of the OBD is lesser than the number of simulation runs of the MUD, but the MUD can be applied more widely than the OBD. Finally, a true vehicle-pedestrian accident case is given, Pc-Crash was used to reconstruct the accident based on all traces provided by the police, and the interval of the impact velocity of the vehicle was calculated using the OBD, results showed that the research is meaningful in practice.

Erosion and its Effect on a Water-Cooled Turbine

1978 ◽  
Author(s):  
Max Freedman
Keyword(s):  
Impact Velocity ◽  
Gas Turbines ◽  
Mass Loss Rate ◽  
Impact Angle ◽  
Aluminum Specimen ◽  
High Impact Velocity ◽  
Short Time ◽  
Impact Angles ◽  
The Impact

Erosion tests were run to obtain data for designing a water-cooled gas turbine collection shroud. All tests utilized a coherent stream of water ejected from a static nozzle against stationary small block specimens. Twenty-one tests were run with aluminum specimens and 16 more tests with other materials. The impact velocity was varied from 165 to 270 m/s (540 to 890 fps). The impact angle was varied from 10 to 90 deg. The mass loss rate results generally show four erosion regions, which are consistent with the literature. A correlation between regions two and four was found. Aluminum specimen erosion rate was found to be unexpectedly high with impact angles of 10 deg and moderate-to-high impact velocity. No report of previous liquid erosion work at impact angles less than 30 deg was found; since it is expected that water-cooled gas turbines will operate at impact angles of about 15 deg, erosion in this low impact angle region should be studied. If the correlation between erosion regions two and four can be quantized, then very short-time tests could be used to predict long-term erosion at minimal cost.

Evaluating Impact Properties of Cement Clinker at Different Angle for Impact Indentation

2011 ◽  
Vol 492 ◽  
pp. 43-46
Author(s):  
Xiu Fang Wang ◽  
Yi Wang Bao ◽  
Yan Qiu ◽  
Xiao Gen Liu ◽  
Yuan Tian
Keyword(s):  
Impact Velocity ◽  
Impact Force ◽  
Surface Damage ◽  
Impact Angle ◽  
Cement Clinker ◽  
Damage Degree ◽  
Indentation Tests ◽  
Impact Angles ◽  
The Impact ◽  
Peak Impact Force

Spherical impact indentation tests with different impact angles (90°, 60°, 45°, and 30°) was carried out to understand the effect of impact angles on damage degree of cement clinker. A linear rail which can adjust angle to alter impact velocity was used to guide the slipping impact head to impact the sample. The different steel wedge was used to change the impact angle. It is found that the area of damage surface for cement clinker is most serious the peak impact force for surface damage decreases but the contact indentation becomes longer with decreasing impact angle when the impact angle is 45°. Under almost the same impact velocity, the smaller the impact angle, the higher the impulse, the longer contact time, and the peak impact force of 45° is maximum.

Analysis of Bloodstains Patterns at Sharp Impact Angles

2016 ◽  
Author(s):  
Mohammad Moshfeghi ◽  
Iman Rahimipetroudi ◽  
Nahmkeon Hur
Keyword(s):  
Crime Scene ◽  
Impact Angle ◽  
Equivalent Diameter ◽  
Glycerol Solution ◽  
Fluid Viscosity ◽  
Bloodstain Pattern ◽  
Droplet Sizes ◽  
Impact Angles ◽  
The Impact ◽  
Inclined Surface

Bloodstain pattern analysis is of tremendous value for the investigation of the evidence at the crime scene. Analyzing the bloodstain patterns provides an appropriate method for retracing the origin of blood droplets and also reconstruction of the crime scene. The patterns of the bloodstains on the floors and walls are determined by the impact conditions of blood drops such as droplet sizes, impact angles and velocities. The objective of this work is to study the bloodstain patterns on an inclined surface, in order to categorize the bloodstain shapes. The experiments have been carried out using a 38% glycerol solution at room temperature between 16° C∼21° C. The experiments have been done for three different droplet diameters, five different velocities and four different surface inclinations. The blood-mimicking fluid viscosity and density have been measured at the same temperature range with the experiments. The results have been investigated in terms of bloodstain shape and patterns and three different categories have been determined. In addition, a new mathematical formula has been derived based on the equivalent diameter of the bloodstains, which relates the bloodstain dimensions to the droplet Reynolds and Weber numbers. It has been shown that the proposed formula fits more accurately with the experimental results for high impact angle cases as compared to the classical formula.

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