A Study on Dynamic Characteristics of Hyper-Elastic Shock Programmer with Truncated Conical Shape

2013 ◽  
Vol 871 ◽  
pp. 240-246
Author(s):  
Tae Ho Yang ◽  
Young Shin Lee ◽  
Yoon Jae Kim ◽  
Tae Hyeong Kim ◽  
Chang Won Shul ◽  
...  
Keyword(s):  
Elastic Material ◽  
Impact Test ◽  
Time History ◽  
Material Model ◽  
Wave Shape ◽  
Time Duration ◽  
Conical Shape ◽  
Design Variables ◽  
Hyper Elastic ◽  
The Impact

Polyurethane (PU) S80A was used as the material of the elastomer of the shock programmer in this paper. To validate Ogden hyper-elastic material model in simulation, the small impact test was performed. As the comparison for the time history of the acceleration between the impact test and simulation was performed. Using the cylindrical shock programmer, the constant used in Ogden hyper-elastic material model was calculated. The wave shape of the acceleration was obtained with the noised sign. To clearly obtain the wave shape of the acceleration the cylindrical shock programmer, the truncated conical shock programmer was used. Using the Ogden hyper-elastic material model, design variables of the shock programmer with the truncated conical shape was studied. Using the shock programmer with truncated conical shape the range on the level and time duration of the acceleration in simulation was from 494.9 m/s2 to 10941 m/s2 and from 1.3 msec to 23.5 msec, respectively.

Numerical Simulations of the Drifting Ice Sheets Collision with the Bridge Pier

2013 ◽  
Vol 368-370 ◽  
pp. 1383-1386
Author(s):  
Lian Zhen Zhang ◽  
Wei Xiong
Keyword(s):  
Numerical Simulations ◽  
Ice Sheets ◽  
Ice Sheet ◽  
Time History ◽  
Material Model ◽  
Bridge Pier ◽  
Bridge Design ◽  
Drifting Ice ◽  
Collision Force ◽  
The Impact

The drifting ice sheets impact with the bridge pier and other hydraulic structures in the rivers, which may damage even cause collapse of the structures. In this paper, the FEM software package LS-DYNA was used to performed the numerical simulations of the collision process of the ice sheets and the bridge piers to make clear the interaction between them and to understand the failure mechanism of the ice sheet. The elastic strain-stress model with von mises failure criterion was used to describe the ice material. The brittle damage material model was used to describe the concrete pier. Three types thickness of ice sheets were performed at various velocity of the ice sheet respectively. The impact process of every case were displayed and the time history curve of the collision force were given out. The simulations results show that the peak value of the collision force time history curve increases with the velocity of the sheet firstly and then decreases with the velocity of the ice sheet. There is one critical velocity which relate to the compressive strength of the ice sheet. The simulation result were also compared with the different bridge design code, which show that the code result is more conservative in bridge design.

IMPACT FORCE RESPONSE OF SHORT CONCRETE FILLED STEEL TUBULAR COLUMNS UNDER AXIAL LOAD

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1361-1368 ◽  
Author(s):  
GOUPING REN ◽  
ZHU LI
Keyword(s):  
Impact Force ◽  
Time History ◽  
Material Model ◽  
Critical Energy ◽  
Steel Tube ◽  
Peak Force ◽  
Impact Speed ◽  
Tubular Columns ◽  
Unitary Model ◽  
The Impact

The impact test on short concrete filled steel tubular column was conducted through DHR-9401 dropped hammer tester. Based on analysis on recorded time-history curve of impact force, the relations of impact force with respect to confining effect coefficient and impact speed are obtained. So are done that of the impact duration. By use of ANSYS/LS-DYNA, values of impact peak force in relation with those of impact speed were computed in the case of unitary material model and composite material model respectively. The simulation results show that peak force-speed curve of unitary model has better description of test data than that of composite one. Critical energy is found to increase linearly with the steel ratio when steel tube and concrete remain unchanged.

EFFECT OF MATERIAL MODEL SELECTION ON LATERAL IMPACT SIMULATIONS OF PELVIC COMPLEX

2019 ◽  
Vol 19 (07) ◽  
pp. 1940032
Author(s):  
AILI QU ◽  
DONGMEI WANG ◽  
FANG WANG ◽  
QIU’GEN WANG
Keyword(s):  
Model Selection ◽  
Pelvic Fracture ◽  
Elastic Material ◽  
Pelvic Ring ◽  
Material Model ◽  
Fracture Pattern ◽  
Pelvic Bone ◽  
Lateral Impact ◽  
Impact Simulations ◽  
The Impact

Material mechanical behavior plays an important role in pelvic complex simulation under lateral impact. Aiming to investigate effects of material model selection on the responses of lateral impact simulations, a seating pelvic complex model was constructed. The model was subjected to a series of impacts at velocity of 3–10[Formula: see text]m/s, and two material models were, respectively, assigned to the pelvic bone to evaluate the accuracy of the simulation. The results showed that the pelvic response and fracture pattern with plastic–elastic material model agreed well with the literature, while linear elastic material model was dissatisfied factory, especially the pelvic response at low velocity deviated from most cadaveric test data. In addition, drastic change of arterial pressure was responsible for hemorrhages associated with pelvic fracture. Ligament loading sequence verified that the posterior pelvic ring bore the greatest amount of load during the impact. Based on the above findings, we concluded that a plastic–elastic with strain rate effect material model can improve the simulation accuracy of pelvic complex under lateral impact, and pelvic fracture pattern may help to estimate the parameters’ selection in impact simulation.

Effect of change of material model in Mooney Rivlin hyper-elastic material

2020 ◽  
Vol 26 ◽  
pp. 2511-2514 ◽  
Author(s):  
Suraj ◽  
Abhishek Kumar ◽  
Bikas Prasad ◽  
Kaushik Kumar
Keyword(s):  
Elastic Material ◽  
Material Model ◽  
Hyper Elastic

Strain Measurement in the Steel Shell Surface Impacted by a Falling Ball

2014 ◽  
Vol 548-549 ◽  
pp. 401-405
Author(s):  
Wei Liu ◽  
Jie Song ◽  
Hua Guan ◽  
Xiao Han ◽  
Jian Zhong Wu ◽  
...  
Keyword(s):  
Impact Test ◽  
Bridge Circuit ◽  
Time History ◽  
Wheatstone Bridge ◽  
Free Fall ◽  
Test Method ◽  
Steel Shell ◽  
Maximum Strain ◽  
Shell Surface ◽  
The Impact

In order to study the maximum strain of steel shell surface under the impact of a falling ball, a thin shell model and the strain time history curves of impact are achieved by ANSYS/LS-DYNA. A deformation behavior of the shell was calibrated from the test which uses a ball free fall and some resistance strain gauges pasted to the inner surface of an iron shell box. The gauges are connected as inputs to a Wheatstone bridge circuit and an Oscilloscope is used to observe the output. The results show the impact test and ANSYS/LS-DYNA simulation results are smoothly consistent with the strain of the test at the maximum strain amplitude of the model, and the maximum difference is 9.5%. Accurate results can be achieved by combining the test method and the simulation approach as an industrial application.

Force Reconstruction for Impact Tests

1991 ◽  
Vol 113 (2) ◽  
pp. 192-200 ◽  
Author(s):  
V. I. Bateman ◽  
T. G. Carne ◽  
D. L. Gregory ◽  
S. W. Attaway ◽  
H. R. Yoshimura
Keyword(s):  
Data Reduction ◽  
Impact Test ◽  
Time History ◽  
Scale Model ◽  
Accelerometer Data ◽  
Acceleration Technique ◽  
Reduction Techniques ◽  
Force Reconstruction ◽  
Reduction Methods ◽  
The Impact

Two force reconstruction techniques were used to evaluate the impact test of a scale model nuclear transportation cask dropped 30 ft. onto an unyielding target. The two techniques are: the sum of weighted acceleration technique (SWAT) and the deconvolution technique (DECON). A brief description and the calibration of the techniques as applied to the cask are presented. For the impact test, both techniques yielded very similar resultant forces and provided more accurate definition of the force-time history for the cask than is available from conventional data reduction methods. An applied moment, measurement previously unobtainable from conventional accelerometer data reduction techniques, was determined with SWAT. The angular velocity calculated with SWAT was verified with photometric measurements.

scholarly journals Identification of Material Parameters of a Hyper-Elastic Body With Unknown Boundary Conditions

2018 ◽  
Vol 85 (5) ◽  
Author(s):  
M. Hajhashemkhani ◽  
M. R. Hematiyan ◽  
S. Goenezen
Keyword(s):  
Boundary Conditions ◽  
Elastic Material ◽  
Material Properties ◽  
Soft Tissues ◽  
Material Model ◽  
Unknown Boundary ◽  
Material Parameters ◽  
Hyper Elastic ◽  
Unknown Boundary Conditions

Identification of material properties of hyper-elastic materials such as soft tissues of the human body or rubber-like materials has been the subject of many works in recent decades. Boundary conditions generally play an important role in solving an inverse problem for material identification, while their knowledge has been taken for granted. In reality, however, boundary conditions may not be available on parts of the problem domain such as for an engineering part, e.g., a polymer that could be modeled as a hyper-elastic material, mounted on a system or an in vivo soft tissue. In these cases, using hypothetical boundary conditions will yield misleading results. In this paper, an inverse algorithm for the characterization of hyper-elastic material properties is developed, which takes into consideration unknown conditions on a part of the boundary. A cost function based on measured and calculated displacements is defined and is minimized using the Gauss–Newton method. A sensitivity analysis is carried out by employing analytic differentiation and using the finite element method (FEM). The effectiveness of the proposed method is demonstrated through numerical and experimental examples. The novel method is tested with a neo–Hookean and a Mooney–Rivlin hyper-elastic material model. In the experimental example, the material parameters of a silicone based specimen with unknown boundary condition are evaluated. In all the examples, the obtained results are verified and it is observed that the results are satisfactory and reliable.

Study of Crash Acceleration Curves on the Side-Impact Test

2011 ◽  
Vol 230-232 ◽  
pp. 1335-1339
Author(s):  
Tso Liang Teng ◽  
Cho Chung Liang ◽  
Chien Jong Shih ◽  
Da An Fung
Keyword(s):  
Impact Test ◽  
Time History ◽  
Side Impact ◽  
Curve Shape ◽  
Crash Safety ◽  
Vehicle Crash ◽  
Vehicle Impact ◽  
Occupant Injury ◽  
Time History Response ◽  
The Impact

The vehicle crash acceleration curve is an important measured data which can represents a time history response of a vehicle during an impact test. To investigate the crash acceleration curve not only can realize the dynamic response and energy change of the impact process, but also able to assess the severity of occupant injury during a crash. The side-impact crash acceleration curve was investigated in this study. The characteristics of the measured crash curve of vehicle impact test can be analyzed to discuss the effect of the crash curve shape on the occupant injury. The shape, amplitude and duration characteristics of curve were discussed herein. Furthermore, a better curve shape to effectively reduce occupant injury was proposed. The trend of curve shape obtained in this study could help evaluate vehicle crash safety and guide the future development of safety technologies.

Sign in / Sign up

Export Citation Format

Share Document