A study of the pedestrian impact kinematics using finite element dummy models: the corridors and dimensional analysis scaling of upper-body trajectories

2008 ◽  
Vol 13 (5) ◽  
pp. 469-478 ◽  
Author(s):  
Costin D. Untaroiu ◽  
Jaeho Shin ◽  
Johan Ivarsson ◽  
Jeff R. Crandall ◽  
Damien Subit ◽  
...  
Keyword(s):  
Finite Element ◽  
Dimensional Analysis ◽  
Upper Body ◽  
Pedestrian Impact

scholarly journals A Computationally Efficient Finite Element Pedestrian Model for Head Safety: Development and Validation

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Guibing Li ◽  
Zheng Tan ◽  
Xiaojiang Lv ◽  
Lihai Ren
Keyword(s):  
Finite Element ◽  
Human Body ◽  
Head Injuries ◽  
Computing Time ◽  
Upper Body ◽  
Vehicle Crashes ◽  
Lateral Impact ◽  
Computationally Efficient ◽  
Pedestrian Impact ◽  
Human Body Models

Head injuries are often fatal or of sufficient severity to pedestrians in vehicle crashes. Finite element (FE) simulation provides an effective approach to understand pedestrian head injury mechanisms in vehicle crashes. However, studies of pedestrian head safety considering full human body response and a broad range of impact scenarios are still scarce due to the long computing time of the current FE human body models in expensive simulations. Therefore, the purpose of this study is to develop and validate a computationally efficient FE pedestrian model for future studies of pedestrian head safety. Firstly, a FE pedestrian model with a relatively small number of elements (432,694 elements) was developed in the current study. This pedestrian model was then validated at both segment and full body levels against cadaver test data. The simulation results suggest that the responses of the knee, pelvis, thorax, and shoulder in the pedestrian model are generally within the boundaries of cadaver test corridors under lateral impact loading. The upper body (head, T1, and T8) trajectories show good agreements with the cadaver data in vehicle-to-pedestrian impact configuration. Overall, the FE pedestrian model developed in the current study could be useful as a valuable tool for a pedestrian head safety study.

Application of the method of dimensional analysis in laser-shock-wave processing of titanium alloys with shape memory

2021 ◽  
pp. 66-72
Author(s):  
Keyword(s):  
Shock Wave ◽  
Finite Element ◽  
Plastic Zone ◽  
Shape Memory ◽  
Dimensional Analysis ◽  
Peak Pressure ◽  
Laser Shock ◽  
Zone Depth ◽  
Peak Pressures ◽  
Laser Shock Wave

The processes of laser-shock-wave processing of NiTi alloys with shape memory effect are investigated by the methods of dimensional analysis and finite element modeling. The dependences of the depth of the plastic zone on the peak pressure in the shock wave and the duration of the laser pulse are obtained at different peak pressures. Keywords: shape memory alloys, laser-shock-wave processing, dimensional analysis, residual stresses, plastic zone depth. [email protected]

Preliminary Ship Design Using One and Two-Dimensional Models

1999 ◽  
Vol 36 (02) ◽  
pp. 102-112
Author(s):  
Michael D. A. Mackney ◽  
Carl T. F. Ross
Keyword(s):  
Finite Element ◽  
Dimensional Analysis ◽  
Three Dimensional ◽  
Two Dimensional ◽  
One Dimensional ◽  
Dimensional Finite Element ◽  
Dimensional Models ◽  
Support Conditions ◽  
The One ◽  
Three Dimensional Finite Element

Computational studies of hull-superstructure interaction were carried out using one-, two-and three-dimensional finite element analyses. Simplification of the original three-dimensional cases to one- and two-dimensional ones was undertaken to reduce the data preparation and computer solution times in an extensive parametric study. Both the one- and two-dimensional models were evaluated from numerical and experimental studies of the three-dimensional arrangements of hull and superstructure. One-dimensional analysis used a simple beam finite element with appropriately changed sections properties at stations where superstructures existed. Two-dimensional analysis used a four node, first order quadrilateral, isoparametric plane elasticity finite element, with a corresponding increase in the grid domain where the superstructure existed. Changes in the thickness property reflected deck stiffness. This model was essentially a multi-flanged beam with the shear webs representing the hull and superstructure sides, and the flanges representing the decks One-dimensional models consistently and uniformly underestimated the three-dimensional behaviour, but were fast to create and run. Two-dimensional models were also consistent in their assessment, and considerably closer in predicting the actual behaviours. These models took longer to create than the one-dimensional, but ran in very much less time than the refined three-dimensional finite element models Parametric insights were accomplished quickly and effectively with the simplest model and processor, but two-dimensional analyses achieved closer absolute measure of the displacement behaviours. Although only static analysis with simple loading and support conditions were presented, it is believed that similar benefits would be found for other loadings and support conditions. Other engineering components and structures may benefit from similarly judged simplification using one- and two-dimensional models to reduce the time and cost of preliminary design.

GENERALIZED FINITE ELEMENT METHOD FOR NONLINEAR THREE-DIMENSIONAL ANALYSIS OF SOLIDS

2008 ◽  
Vol 05 (01) ◽  
pp. 37-62 ◽  
Author(s):  
SERGIO PERSIVAL BARONCINI PROENÇA ◽  
IVAN FRANCISCO RUIZ TORRES
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Dimensional Analysis ◽  
Damage Model ◽  
Three Dimensional ◽  
Generalized Finite Element Method ◽  
Good Tool ◽  
Selective Enrichment ◽  
Generalized Finite Element ◽  
Element Method

The Generalized Finite Element Method (GFEM) is employed in this paper for the numerical analysis of three-dimensional solids under nonlinear behavior. A brief summary of the GFEM as well as a description of the formulation of the hexahedral element based on the proposed enrichment strategy are initially presented. Next, in order to introduce the nonlinear analysis of solids, two constitutive models are briefly reviewed: Lemaitre's model, in which damage and plasticity are coupled, and Mazars's damage model suitable for concrete under increased loading. Both models are employed in the framework of a nonlocal approach to ensure solution objectivity. In the numerical analyses carried out, a selective enrichment of approximation at regions of concern in the domain (mainly those with high strain and damage gradients) is exploited. Such a possibility makes the three-dimensional analysis less expensive and practicable since re-meshing resources, characteristic of h-adaptivity, can be minimized. Moreover, a combination of three-dimensional analysis and the selective enrichment presents a valuable good tool for a better description of both damage and plastic strain scatterings.

Finite element three-dimensional analysis of the vibrational behaviour of the Langevin-type transducer

Ultrasonics ◽  
2002 ◽  
Vol 40 (1-8) ◽  
pp. 513-517 ◽  
Author(s):  
Antonio Iula ◽  
Fernando Vazquez ◽  
Massimo Pappalardo ◽  
Juan A. Gallego
Keyword(s):  
Finite Element ◽  
Dimensional Analysis ◽  
Three Dimensional ◽  
Type Transducer

Investigation of Vibration Characteristics of the Ligamentous Lumbar Spine Using the Finite Element Approach

1994 ◽  
Vol 116 (4) ◽  
pp. 377-383 ◽  
Author(s):  
Vijay K. Goel ◽  
Hosang Park ◽  
Weizeng Kong
Keyword(s):  
Finite Element ◽  
Resonant Frequency ◽  
Cyclic Load ◽  
Static Load ◽  
Three Dimensional ◽  
Element Model ◽  
Upper Body ◽  
Experimental Investigations ◽  
Flexion Extension

A nonlinear, three-dimensional finite element model of the ligamentous L4-SI segment was developed to analyze the dynamic response of the spine in the absence of damping. The effects of the upper body mass were simulated by including a mass of 40 kg on the L4 vertebral body. The modal analyses of the model indicated a resonant frequency of 17.5 Hz in axial mode and 3.8 Hz in flexion-extension mode. Accordingly, the predicted responses for the cyclic load of −400 ± 40 N applied at four different frequencies (5, 11, 16.5, and 25 Hz) were compared with the corresponding results for axial compressive static loads (−360, and −440 N). As compared to the static load cases, the predicted responses were higher for the cyclic loading. For example, the effect of cyclic load at 11 Hz was to produce significant changes (9.7 – 19.0 percent) in stresses, loads transmitted through the facets, intradiscal pressure (IDP), disk bulge, as compared to the static load predictions. The responses were found to be frequency dependent as well; supporting the in vivo observations of other investigators that the human spine has a resonant frequency. For example, the 11 Hz model (DYN11) compared to the DYN5 model showed an increase in majority of the predicted parameters. The parameters showed an increase with frequency until 17.5 Hz (resonant frequency of the model); thereafter a decrease at 25 Hz. A chronic change in these parameters, especially at the resonant frequency, beyond the “base” values may trigger the bone remodeling process leading to spinal degeneration/disorders associated with chronic vibration exposure. Future directions for extending the present model as a complement to the experimental investigations are also discussed.

Computing Thin Film Mechanical Properties With the Oliver and Pharr Method

1999 ◽  
Vol 593 ◽  
Author(s):  
P.J. Wolff ◽  
B.N. Lucas ◽  
E.G. Herbert
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Finite Element ◽  
Finite Element Modeling ◽  
Dimensional Analysis ◽  
Film Properties ◽  
Element Modeling ◽  
Indentation Tests

ABSTRACTA commonly used technique to compute mechanical properties from indentation tests is the Oliver and Pharr method. Using dimensional analysis and finite element modeling, this paper investigates errors when the Oliver and Pharr method is used to compute thin film properties.

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