Development of a Finite Element Model for Simulation of Rollover Crashes

2007 ◽  
Author(s):  
Jingwen Hu ◽  
Chunsheng Ma ◽  
King H. Yang ◽  
Clifford C. Chou ◽  
Albert I. King ◽  
...  
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Development Stage ◽  
Rigid Body Dynamics ◽  
Lateral Acceleration ◽  
Computational Time ◽  
Fe Model ◽  
Vertical Acceleration ◽  
Fe Method ◽  
Vehicle Crashworthiness

Rollover crashes are complex by their very nature, and have stimulated many researches aimed at improved occupant safety. In order to investigate the vehicle crashworthiness during rollovers, several test modes are generally used to replicate different real world rollover scenarios. However, such tests are very expensive, especially during the development stage of a new car line. Computer modeling is a cost-effective way to study rollover crashes. However, a survey of literature showed that only rigid-body dynamics based models have been used for rollover simulations. It is well known that this class of models cannot be used to simulate component deformation and structural collapses. Finite element (FE) method, which has been widely used to simulate frontal and side crashes, was rarely used for simulating rollover crashes, due mainly to the relative long duration of a rollover crash. The objective of this study was to develop an FE model for investigating vehicle crashworthiness during three commonly used rollover tests. An FE model of an SUV was developed in this study. Several sub-models, namely the vehicle structure sub-model, the tire sub-model, the suspension system sub-model, the restraint system sub-model, and the dummy model were generated and integrated together. The structure model was first used to simulate the roof crush test as prescribed in FMVSS 216. The resulting load versus roof crush curve matched well against test results. The integrated model was then used to simulate three laboratory-based rollover test modes, namely the SAE J2114 dolly test, curb-trip test, and corkscrew test. For each test mode, up to 1.5 seconds of simulation time (about 1 full vehicle roll) were computed. The vehicle kinematics, including the angular velocity, lateral acceleration, and vertical acceleration during these three test modes were computed and compared with experimental data. The simulated dummy head accelerations, timing and location of the most severe impact to the dummy’s head were also compared with the experimental results. Results showed very good agreement between the tests and simulations. In order to reduce the computational time, multiple CPUs were used. Approximately ten hours were required to run a 1.5 second rollover simulation on eight CPUs. Thus, simulating rollovers using FE method is quickly becoming a reality.

Thermo-mechanical analysis of train wheel-rail contact using a novel finite-element model

2020 ◽  
Vol 72 (5) ◽  
pp. 687-693
Author(s):  
Liuqing Yang ◽  
Ming Hu ◽  
Deming Zhao ◽  
Jing Yang ◽  
Xun Zhou
Keyword(s):  
Finite Element ◽  
Peer Review ◽  
Frictional Heating ◽  
Element Model ◽  
Mechanical Analysis ◽  
Partial Slip ◽  
Computational Time ◽  
Fe Model ◽  
Content Type ◽  
Explicit Finite Element

Purpose The purpose of this paper is to develop a novel method for analyzing wheel-rail (W-R) contact using thermo-mechanical measurements and study the effects of heating on the characteristics of W-R contact under different creepages. Design/methodology/approach This study developed an implicit-explicit finite element (FE) model which could solve both partial slip and full sliding problems by setting different angular velocities on the wheels. Based on the model, four material types under six different creepages were simulated. Findings The results showed that frictional heating significantly affected the residual stress distribution under large creepage conditions. As creepage increased, the temperature of the wheel tread and rail head rose and the peak value was located at the trailing edge of the contact patch. Originality/value The proposed FE model could reduce computational time and thus cost to about one-third of the amount commonly found in previous literature. Compared to other studies, these results are in good agreement and offer a reasonable alternative method for analyzing W-R contact under various conditions. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2019-0298

Development and Preliminary Validation of a Parametric Pediatric Head Finite Element Model for Population-Based Impact Simulations

2011 ◽  
Author(s):  
Jingwen Hu ◽  
Zhigang Li ◽  
Jinhuan Zhang
Keyword(s):  
Finite Element ◽  
Head Injury ◽  
Element Model ◽  
The United States ◽  
Population Based ◽  
Head Model ◽  
Fe Model ◽  
Fe Method ◽  
Preliminary Validation ◽  
Head Responses

Head injury is the leading cause of pediatric fatality and disability in the United States (1). Although finite element (FE) method has been widely used for investigating head injury under impact, there are only a few 3D pediatric head FE models available in the literature, including a 6-month-old child head model developed by Klinich et al (2), a newborn, a 6-month-old and a 3-year-old child head model developed by Roth et al. (3, 4, 5), and a 1.5-month-old infant head model developed by Coats et al (6). Each of these models only represents a head at a single age with single head geometry. Nowadays, population-based simulations are getting more and more attention. In population-based injury simulations, impact responses for not only an individual but also a group of people can be predicted, which takes into account variations among people thus providing more realistic predictions. However, a parametric pediatric head model capable of simulating head responses for different children at different ages is currently not available. Therefore, the objective of this study is to develop a fast and efficient method to build pediatric head FE models with different head geometries and skull thickness distributions. The method was demonstrated by morphing a 6-month-old infant head FE model into three newborn infant head FE models and by validating three morphed head models against limited cadaveric test data.

Computationally Efficient, Explicit Finite Element Model for Evaluation of Patellofemoral Mechanics

2007 ◽  
Author(s):  
Mark A. Baldwin ◽  
Paul J. Rullkoetter
Keyword(s):  
Finite Element ◽  
Contact Mechanics ◽  
Probabilistic Approach ◽  
Element Model ◽  
Relevant Information ◽  
Composite Fiber ◽  
Computational Time ◽  
Patient Specific ◽  
Fe Model ◽  
Explicit Finite Element

Patient-specific finite element (FE) models can provide clinically relevant information about contact mechanics and kinematics that may be difficult or infeasible to obtain otherwise, and have potential to guide pre-operative planning. However, substantial uncertainty in model variables exists in patient-specific modeling, and suggests a probabilistic approach. Although efficient probabilistic methodology has been recently developed, multiple analyses are still required, and computational time for a fully deformable FE model throughout a flexion cycle has typically made this impractical. Therefore, the goal of the present study was to develop an explicit FE model of the patellofemoral joint with deformable cartilage and deformable, wrapping extensor tendons, and to compare kinematic and contact mechanics results with a model modified for computational efficiency. The efficient model incorporated rigid femoral and patellar cartilage representation with an optimized contact pressure–surface overclosure relationship, and composite-fiber tendons.

Development and numerical validation of a finite element model of the muscle standardized femur

2003 ◽  
Vol 217 (3) ◽  
pp. 165-172 ◽  
Author(s):  
K Polgar ◽  
H S Gill ◽  
M Viceconti ◽  
D W Murray ◽  
J J O'Connor
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Data Sets ◽  
Fe Model ◽  
Fe Method ◽  
Human Femur ◽  
Numerical Studies ◽  
Physiological Loading ◽  
Physiological Load

The human femur is one of the parts of the musculo-skeletal system most frequently analysed by means of the finite element (FE) method. Most FE studies of the human femur are based on computed tomography data sets of a particular femur. Since the geometry of the chosen sample anatomy influences the computed results, direct comparison across various models is often difficult or impossible. The aim of the present work was to develop and validate a novel three-dimensional FE model of the human femur based on the muscle standardized femur (MuscleSF) geometry. In the new MuscleSF FE model, the femoral attachment of each muscle was meshed separately on the external bone surface. The model was tested under simple load configurations and the results showed good agreement with the converged solution of a former study. In the future, using the validated MuscleSF FE model for numerical studies of the human femur will provide the following benefits: (a) the numerical accuracy of the model is known; (b) muscle attachment areas are incorporated in the model, therefore physiological loading conditions can be easily defined; (c) analyses of the femur under physiological load cases will be replicable; (d) results based on different load configurations could be compared across various studies.

Application of 2D finite element model for nonlinear dynamic analysis of clamp band joint

2015 ◽  
Vol 23 (9) ◽  
pp. 1480-1494 ◽  
Author(s):  
Zhaoye Qin ◽  
Delin Cui ◽  
Shaoze Yan ◽  
Fulei Chu
Keyword(s):  
Finite Element ◽  
Model Updating ◽  
Three Dimensional ◽  
Nonlinear Dynamic Analysis ◽  
Element Model ◽  
Fe Model ◽  
Fe Method ◽  
Static Test ◽  
Joint Structure ◽  
2D Model

Due to frictional slippage between the joint components, clamp band joints may generate nonlinear stiffness and friction damping, which will affect the dynamics of the joint structures. Accurate modeling of the frictional behavior in clamp band joints is crucial for reliable estimation of the joint structure dynamics. While the finite element (FE) method is a powerful tool to analyze structures assembled with joints, it is computationally expensive and inefficient to perform transient analyses with three-dimensional (3D) FE models involving contact nonlinearity. In this paper, a two-dimensional (2D) FE model of much more efficiency is applied to investigate the dynamics of a clamp band jointed structure subjected to longitudinal base excitations. Prior to dynamic analyses, the sources of the model inaccuracy are determined, upon which a two-step model updating technique is proposed to improve the accuracy of the 2D model in accordance with the quasi-static test data. Then, based on the updated 2D model, the nonlinear influence of the clamp band joint on the dynamic response of the joint structure is investigated. Sine-sweep tests are carried out to validate the updated 2D FE model. The FE modeling and updating techniques proposed here can be applied to other types of structures of cyclic symmetry to develop accurate model with high computational efficiency.

Improving the Convergence Rate of a Timoshenko Beam Element under Dynamic Conditions

2014 ◽  
Vol 592-594 ◽  
pp. 1080-1083
Author(s):  
Nikhil Narayanan ◽  
P.R. Thyla
Keyword(s):  
Finite Element ◽  
Timoshenko Beam ◽  
Beam Element ◽  
Computational Time ◽  
Fe Model ◽  
Shape Functions ◽  
Fe Method ◽  
3 Dimensional ◽  
Software Packages ◽  
Good Improvement

The deflection and natural frequency of a 3 – Dimensional Timoshenko Beam (TB) is analyzed using Finite Element (FE) method. Significant improvement in computational time can be obtained when new shape functions are used. The results obtained from existing software packages and the new FE model are compared and good improvement is observed.

scholarly journals Stiffness Estimation and Equivalence of Boundary Conditions in FEM Models

2021 ◽  
Vol 11 (4) ◽  
pp. 1482
Author(s):  
Róbert Huňady ◽  
Pavol Lengvarský ◽  
Peter Pavelka ◽  
Adam Kaľavský ◽  
Jakub Mlotek
Keyword(s):  
Boundary Condition ◽  
Finite Element ◽  
Boundary Conditions ◽  
Model Updating ◽  
Element Model ◽  
Computational Time ◽  
Stiffness Coefficients ◽  
First Case ◽  
Numerical Approaches

The paper deals with methods of equivalence of boundary conditions in finite element models that are based on finite element model updating technique. The proposed methods are based on the determination of the stiffness parameters in the section plate or region, where the boundary condition or the removed part of the model is replaced by the bushing connector. Two methods for determining its elastic properties are described. In the first case, the stiffness coefficients are determined by a series of static finite element analyses that are used to obtain the response of the removed part to the six basic types of loads. The second method is a combination of experimental and numerical approaches. The natural frequencies obtained by the measurement are used in finite element (FE) optimization, in which the response of the model is tuned by changing the stiffness coefficients of the bushing. Both methods provide a good estimate of the stiffness at the region where the model is replaced by an equivalent boundary condition. This increases the accuracy of the numerical model and also saves computational time and capacity due to element reduction.

Finite Element Analysis of the Distributed Vibration Absorbers for Structural Noise Control

2005 ◽  
Author(s):  
Ashwini Gautam ◽  
Chris Fuller ◽  
James Carneal
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Base Plate ◽  
Element Model ◽  
Fe Model ◽  
Vibration Absorbers ◽  
Element Analysis ◽  
Poroelastic Media ◽  
Hexahedral Elements ◽  
Component Models

This work presents an extensive analysis of the properties of distributed vibration absorbers (DVAs) and their effectiveness in controlling the sound radiation from the base structure. The DVA acts as a distributed mass absorber consisting of a thin metal sheet covering a layer of acoustic foam (porous media) that behaves like a distributed spring-mass-damper system. To assess the effectiveness of these DVAs in controlling the vibration of the base structures (plate) a detailed finite elements model has been developed for the DVA and base plate structure. The foam was modeled as a poroelastic media using 8 node hexahedral elements. The structural (plate) domain was modeled using 16 degree of freedom plate elements. Each of the finite element models have been validated by comparing the numerical results with the available analytical and experimental results. These component models were combined to model the DVA. Preliminary experiments conducted on the DVAs have shown an excellent agreement between the results obtained from the numerical model of the DVA and from the experiments. The component models and the DVA model were then combined into a larger FE model comprised of a base plate with the DVA treatment on its surface. The results from the simulation of this numerical model have shown that there has been a significant reduction in the vibration levels of the base plate due to DVA treatment on it. It has been shown from this work that the inclusion of the DVAs on the base plate reduces their vibration response and therefore the radiated noise. Moreover, the detailed development of the finite element model for the foam has provided us with the capability to analyze the physics behind the behavior of the distributed vibration absorbers (DVAs) and to develop more optimized designs for the same.

Finite Element Model of Human Cochlea Considering of the Helicotrema Size

2013 ◽  
Vol 456 ◽  
pp. 576-581 ◽  
Author(s):  
Li Fu Xu ◽  
Na Ta ◽  
Zhu Shi Rao ◽  
Jia Bin Tian
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Basilar Membrane ◽  
Round Window ◽  
Element Model ◽  
Oval Window ◽  
Fe Model ◽  
Cochlear Duct ◽  
Human Cochlea ◽  
Set Up

A 2-D finite element model of human cochlea is established in this paper. This model includes the structure of oval window, round window, basilar membrane and cochlear duct which is filled with fluid. The basilar membrane responses are calculated with sound input on the oval window membrane. In order to study the effects of helicotrema on basilar membrane response, three different helicotrema dimensions are set up in the FE model. A two-way fluid-structure interaction numerical method is used to compute the responses in the cochlea. The influence of the helicotrema is acquired and the frequency selectivity of the basilar membrane motion along the cochlear duct is predicted. These results agree with the experiments and indicate much better results are obtained with appropriate helicotrema size.

Dynamic Characteristic Analysis of Irregularity under Turnout by Vehicle-Turnout Rigid-Flexible Coupling Model

2014 ◽  
Vol 945-949 ◽  
pp. 591-595 ◽  
Author(s):  
Meng Chen ◽  
Yan Yun Luo ◽  
Bin Zhang
Keyword(s):  
Finite Element ◽  
Longitudinal Direction ◽  
Element Model ◽  
Vertical Displacement ◽  
Coupling Model ◽  
Interaction Force ◽  
Vertical Acceleration ◽  
Characteristic Analysis ◽  
Flexible Coupling ◽  
Multi Body

Finite element model of track in frog zone is built by vehicle-turnout system dynamics. Considering variation of rail section and elastic support, bending deformation of turnout sleeper, spacer block and sharing pad effects, the track integral rigidity distribution in longitudinal direction is calculated in the model. Vehicle-turnout rigid-flexible coupling model is built by finite element method (FEM), multi-body system (MBS) dynamics and Hertz contact theory. With the regularity solution that different stiffness is applied for rubber pad under sharing pad of different turnout sleeper zone, analysis the variation of vertical acceleration of bogie and wheelset, rail vertical displacement and wheel-rail interaction force, this paper proves that setting reasonable rubber pad stiffness is an efficient method to solve rigidity irregularity problem.

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