scholarly journals The Influence of Origami and Rectangular Crash Box Variations on MPV Bumper with Offset Frontal Test Examination toward Deformability

2017 ◽  
Vol 2 (2) ◽  
Author(s):  
Imam Kusyairi
Keyword(s):  
High Speed ◽  
Oblique Impact ◽  
Isotropic Hardening ◽  
Deformation Pattern ◽  
Frontal Impact ◽  
Simulation Test ◽  
Rectangular Pattern ◽  
Result Show ◽  
Deformation Patterns ◽  
The Impact

Crash Box attached between bumper and chassis of a car serving as a kinetic energy absorber during the collision. In previous research, origami pattern crash box was tested at low speed, high speed, and frontal impact and oblique impact directions. They resulted predictable collapse and stable deformation patterns. It is directly proportional to the energy absorption during the impact. Origami pattern crash box was modeled in square but it cannot be used if it is applied in MPV car, the geometry is unsuitable to the bumper and chassis. Therefore, in this research, the crash box designed according to the size of bumper and chassis of MPV car where its shape is rectangular on the surface. This research will compare the deformation pattern between origami and rectangular crash box adapted to conditions and dimensions of the MPV car. Design built using CAD software and simulation is performed using FEM (Finite Element Method) software. Simulation test modeled with impactor, bumper and crash box, while offset frontal test with 16 km/h impact speed conducted using material bilinear isotropic hardening modeling. Result show that origami pattern crash box has predictable deformation pattern than rectangular pattern crash box.

Rails Deformation Pattern in Frontal Impact

2002 ◽  
Author(s):  
Joseph Hassan ◽  
Guy Nusholtz ◽  
Ke Ding
Keyword(s):  
Wave Propagation ◽  
Real World ◽  
Stress Waves ◽  
Stress Wave Propagation ◽  
Deformation Pattern ◽  
Frontal Impact ◽  
Rigid Barrier ◽  
Final Deformation ◽  
Deformation Patterns ◽  
The Impact

During a vehicle crash stress waves can be generated at the impact point and propagate through the vehicle structure. The generation of these waves is dependent, in general, on the crash type and, in particular, on the impact contact characteristics. This has consequences with respect to different crash barrier interfaces for vehicle evaluation. The two barriers most commonly used to evaluate the response of a vehicle in a frontal impact are the rigid barrier and the offset deformable barrier. They constitute different crash modes, full frontal and offset. Consequently it would be expected that there are different deformation patterns between the two. However, an additional possible contributor to the difference is that an impact into a rigid barrier generates waves of significantly greater stress than impacts with the deformable one. If stress waves are a significant component of real world final deformation patterns then, the choice of barrier interface and its effective stiffness is critical. To evaluate this conjecture, models of two types of rails each undergoing two different types of impacts, are analyzed using an explicit dynamic finite element code. Results show that the energy perturbation along the rail depends on the barrier type and that the early phase of wave propagation has very little effect on the final deformation pattern. This implies that in the real world conditions, the stress wave propagation along the rail has very little effect on the final deformed shape of the rail.

scholarly journals Oblique impact of a smooth body on a thin layer of inviscid liquid

2013 ◽  
Vol 469 (2151) ◽  
pp. 20120615 ◽  
Author(s):  
T. I. Khabakhpasheva ◽  
A. A. Korobkin
Keyword(s):  
Body Surface ◽  
High Speed ◽  
Degrees Of Freedom ◽  
Hydrodynamic Pressure ◽  
Oblique Impact ◽  
The Body ◽  
Second Stage ◽  
Smooth Body ◽  
Vertical Displacements ◽  
The Impact

The two-dimensional motion of a rigid body with a smooth surface is studied during its oblique impact on a liquid layer. The problem is coupled: the three degrees of freedom of the moving body are determined together with the liquid flow and the hydrodynamic pressure along the wetted part of the body surface. The impact process is divided into two temporal stages. During the first stage, the wetted region expands at a high speed with jetting flows at both ends of the wetted region. In the second stage, the free surface of the liquid is allowed to separate from the body surface. The position of the separation point is determined with the help of the Brillouin–Villat condition. Calculations are performed for elliptic cylinders of different masses and with different orientations and speeds before the impact. The horizontal and vertical displacements of the body, as well as its angle of rotation and corresponding speeds are investigated. The model developed remains valid until the body either touches the bottom of the liquid or rebounds from the liquid.

Functional Structure Modeling Based on Fuzzy Inference

2014 ◽  
Vol 651-653 ◽  
pp. 2310-2313
Author(s):  
Ying Ying Yin ◽  
Jin Ying Li
Keyword(s):  
Virtual Environment ◽  
Fuzzy Inference ◽  
Growth Function ◽  
Functional Structure ◽  
Plant Structure ◽  
Simulation Test ◽  
Full Account ◽  
Result Show ◽  
The Impact ◽  
Inference Theory

A method that use fuzzy inference theory to infer the functional structure model is presented. Is based on fuzzy inference theory of artificial intelligence area, analyze and study the measured data, then extract plant growth rule and growth function. When constructing functional structure that can reflect the impact of the environment, the influence of environment was taken into full account. The source and sink organs respond the surrounding virtual environment according to its inbuilt growth function, and produce, allocate and consume assimilates as well as update the L-grammar representing the plant structure, and at last produce the plant that adapt to present virtual environment. The simulation test result show that the model can accurately extract the growth rule, construct right growth function, and vividly reflect the impact of environment.

scholarly journals Ground Simulation Test of 2D Dynamic Overload Environment of Fuze Launching

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Zhibo Wu ◽  
Tiehua Ma ◽  
Yanbing Zhang ◽  
Hongyan Zhang
Keyword(s):  
Pulse Width ◽  
High Speed ◽  
Centrifugal Acceleration ◽  
Simulation Test ◽  
Loading Method ◽  
Study Results ◽  
High Kinetic Energy ◽  
Micro Electromechanical System ◽  
The Impact ◽  
Peak Value

The fuze launch process is subjected to backseat and spin overloads. To address this issue, a loading method of a 2D dynamic acceleration environment was developed in this study for testing fuze antioverload performance on ground. The techniques of flywheel energy storage, high-speed impact, and centrifugal rotation in the track are combined in a dynamic analysis and simulation. First, the flywheel is rotated at a constant speed by a variable-frequency motor to obtain high kinetic energy. Second, an impact hammer is instantaneously released on the specimen at a high speed, loading the backseat acceleration environment. Finally, the impact hammer is retracted, and the specimen is rotated in the track instead of spinning around its axis, thereby loading the centrifugal acceleration environment. The peak value and pulse width of the 2D overload acceleration can be adjusted by changing the speed of the flywheel and buffers in the abovementioned process. The experimental and simulation results observed that the peak value of backseat acceleration could reach 34,559 g, the pulse width was approximately 400 μs, and the peak value of the centrifugal acceleration was 1,020 g. The study results showed that the proposed approach fulfills the requirements of the 2D overload simulation test of the micro-electromechanical system (MEMS) fuze safety and arming mechanism. The proposed loading method has been successfully applied to ground simulation tests of the MEMS fuze safety and arming mechanism.

A discussion on deformation of solids by the impact of liquids, and its relation to rain damage in aircraft and missiles, to blade erosion in steam turbines, and to cavitation erosion - High speed liquid impact

1966 ◽  
Vol 260 (1110) ◽  
pp. 79-85 ◽  
Keyword(s):  
High Speed ◽  
Cavitation Erosion ◽  
High Strain ◽  
Strain Rates ◽  
Steam Turbines ◽  
High Speeds ◽  
Liquid Impact ◽  
Deformation Patterns ◽  
The Impact ◽  
Very High

A study has been made of the deformation at high strain rates of solids under the impact of liquids. A method is described for projecting a short liquid jet against a solid surface at speeds up to 1200 m/s. The flow of the liquid and the deformation of the solid during impact have been examined by high speed photographic methods. An attempt has been made to measure the magnitude and duration of the load by means of a piezoelectric pressure transducer. There is evidence that the liquid behaves initially on impact in a compressible manner. Part of the deformation of the solid is due to this compressible behaviour and part to the erosive shearing action of the liquid flowing at very high speeds out across the surface. The mode of deformation in brittle and in plastically deforming materials has been investigated. The deformation patterns produced are shown to be characteristic of liquid impact. The predominating mechanism of deformation depends on the mechanical properties of the solid and on the velocity of impact.

Oblique Impact of Thick Walled Pressurized Spheres as Used in Tennis

2005 ◽  
Vol 219 (11) ◽  
pp. 1179-1189 ◽  
Author(s):  
S J Haake ◽  
M J Carré ◽  
R Kirk ◽  
S R Goodwill
Keyword(s):  
Coefficient Of Friction ◽  
Momentum Flux ◽  
High Speed ◽  
Reaction Force ◽  
Oblique Impact ◽  
Tennis Ball ◽  
The Coefficient Of Friction ◽  
Impact Phase ◽  
Rotation Set ◽  
The Impact

A model is presented in which the normal impact of a thick walled pressurized sphere, such as a tennis ball, is modelled as a non-linear viscoelastic spring and damper, coupled with momentum-flux forces where the shell wall deforms with high stiffness and damping. These momentum-flux forces are only present in the impact phase and do not appear during restitution. Rotation set up during an oblique impact causes the momentum-flux forces at the front and rear of the sphere to be different such that the total vertical reaction force acts in front of the centre of mass when topspin is present. The sphere was allowed to deform and this caused both the torque and the effective moment of inertia of the sphere to decrease. The result of this is that the deformed sphere gains sufficient spin during impact for reverse slip to occur when the ball reforms towards the end of impact. Tennis balls were projected at two similarly constructed surfaces with a coefficient of friction of 0.51 and 0.62. It was found that displacements and rotations from the model compared well with experimental results recorded using a high-speed video running at 7100 frames per second. The model was able to predict these results with only the coefficient of friction as the varying parameter.

Oblique Impact Analysis of a Golf Ball

2014 ◽  
Vol 566 ◽  
pp. 443-448 ◽  
Author(s):  
Kazuo Arakawa
Keyword(s):  
Angular Velocity ◽  
High Speed ◽  
Impact Analysis ◽  
Video Camera ◽  
Oblique Impact ◽  
Golf Ball ◽  
Normal Velocity ◽  
Velocity Change ◽  
High Speed Video Camera ◽  
The Impact

The oblique impact of a golf ball with a rigid steel target was studied using a high-speed video camera. The video images during the impact were employed to measure the compressional displacement of the ball normal to the target and to determine the normal velocity and acceleration of the ball as a function of time. The rotation angle of the ball was also measured to evaluate the angular velocity during the impact. The results showed that the angular velocity increased and then decreased during the impact. To study the velocity change, we introduced an analytical model and suggested that the ball deformation can play an important role to understand the friction effect during the impact.

Generic Steel Vehicle Front Bumper and Crush Can Assemblies Subjected to a Rigid High Speed Offset Frontal Impact

2016 ◽  
Author(s):  
A. Seyed Yaghoubi ◽  
P. Begeman ◽  
G. Newaz ◽  
D. Board ◽  
Y. Chen ◽  
...  
Keyword(s):  
High Speed ◽  
Test Procedure ◽  
Time History ◽  
Video Tracking ◽  
Experimental Investigations ◽  
Deformation Pattern ◽  
Frontal Impact ◽  
Component Level ◽  
Impact Performance ◽  
Good Agreement

This study presents experimental investigations of generic steel Front Bumper and Crush Can (FBCC) assemblies subjected to a 40% offset frontal impact. As automotive industries aim to reduce overall vehicle weight by applying lighter-weight materials to its structures, component-level studies become important. Computer aided models are valuable tools to complement physical testing by assessing the performances of these structures. Due to the lack of studies on component-level tests with FBCCs, a novel component-level test procedure would be useful to aid in CAE correlation. A sled-on-sled testing method was used to perform all the tests reported here. Impact speed was optimized such that there was no bottoming-out force for this type of test. Three high-speed cameras (HSCs), an infrared (IR) thermal camera, and several accelerometers were utilized to study impact performance of the FBCC structures. The results showed that time histories of displacement and velocity from video tracking and accelerometers were in good agreement. The force-time history and force-displacement curves from different FBCC specimens were consistent and in good agreement with respect to each other with a low coefficient of variation calculated. Post-impact deformation pattern analysis of the samples showed consistent crush patterns. Heat was generated and dissipated at the tip of the crush can and progressed as the can started to fold.

Modeling of Tread Block Contact Mechanics Using Linear Viscoelastic Theory3

2008 ◽  
Vol 36 (3) ◽  
pp. 211-226 ◽  
Author(s):  
F. Liu ◽  
M. P. F. Sutcliffe ◽  
W. R. Graham
Keyword(s):  
High Speed ◽  
Slip Rate ◽  
Material Model ◽  
Contact Forces ◽  
Block Modeling ◽  
Rate Dependent ◽  
Linear Viscoelastic Material ◽  
Linear Viscoelastic ◽  
The Impact ◽  
Good Agreement

Abstract In an effort to understand the dynamic hub forces on road vehicles, an advanced free-rolling tire-model is being developed in which the tread blocks and tire belt are modeled separately. This paper presents the interim results for the tread block modeling. The finite element code ABAQUS/Explicit is used to predict the contact forces on the tread blocks based on a linear viscoelastic material model. Special attention is paid to investigating the forces on the tread blocks during the impact and release motions. A pressure and slip-rate-dependent frictional law is applied in the analysis. A simplified numerical model is also proposed where the tread blocks are discretized into linear viscoelastic spring elements. The results from both models are validated via experiments in a high-speed rolling test rig and found to be in good agreement.

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