scholarly journals Numerical Simulation of Vehicle–Lighting Pole Crash Tests: Parametric Study of Factors Influencing Predicted Occupant Safety Levels

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2822
Author(s):  
Paweł Baranowski ◽  
Krzysztof Damaziak
Keyword(s):  
Impact Velocity ◽  
Parametric Study ◽  
Test Procedure ◽  
Mesh Size ◽  
Severity Index ◽  
Sensitivity Study ◽  
Physical Parameters ◽  
Occupant Safety ◽  
Factors Influencing ◽  
Particle Hydrodynamics

In this paper, numerical simulations of the EN 12767 test procedure for a vehicle–lighting pole crash are presented. A representative soil–vehicle–lighting pole model is first developed. The Geo Metro vehicle model is used, and significant attention is given to representing the soil and its interaction with the traffic pole. Soil is represented using smoothed particle hydrodynamics (SPH) coupled with finite elements (FEs). A parametric study is carried out to investigate the key factors influencing the outcomes and consequently the estimation of the occupant safety levels during crash scenario described in EN 12767. First, a sensitivity study of lighting pole mesh is conducted As a result, the optimal mesh size is used for further studies regarding physical parameters such as soil properties and friction coefficient in vehicle–pole interfaces. Friction and mesh size are found to have a considerable influence on the acceleration severity index (ASI), theoretical head impact velocity (THIV), post-impact velocity and vehicle behavior during the lighting pole crash scenario.

Quantify Resonance Inspection With Finite-Element-Based Modal Analyses

2010 ◽  
Author(s):  
K. Lai ◽  
X. Sun ◽  
C. Dasch
Keyword(s):  
Finite Element ◽  
High Stress ◽  
Mesh Size ◽  
Element Model ◽  
Sensitivity Study ◽  
Production Level ◽  
Mode Shapes ◽  
Resonance Spectroscopy ◽  
Frequency Spectra ◽  
Resonance Frequencies

Resonance inspection uses the natural acoustic resonances of a part to identify anomalous parts. Modern instrumentation can measure the many resonant frequencies rapidly and accurately. Sophisticated sorting algorithms trained on sets of good and anomalous parts can rapidly and reliably inspect and sort parts. This paper aims at using finite-element-based modal analysis to put resonance inspection on a more quantitative basis. A production-level automotive steering knuckle is used as the example part for our study. First, the resonance frequency spectra for the knuckle are measured with two different experimental techniques. Next, scanning laser vibrometry is used to determine the mode shape corresponding to each resonance. The material properties including anisotropy are next measured to high accuracy using resonance spectroscopy on cuboids cut from the part. Then, finite element model (FEM) of the knuckle is generated by meshing the actual part geometry obtained with computed tomography (CT). The resonance frequencies and mode shapes are next predicted with a natural frequency extraction analysis after extensive mesh size sensitivity study. The good comparison between the predicted and the experimentally measured resonance spectra indicate that finite-element-based modal analyses have the potential to be a powerful tool in shortening the training process and improving the accuracy of the resonance inspection process for a complex, production level part. The finite element based analysis can also provide a means to computationally test the sensitivity of the frequencies to various possible defects such as porosity or oxide inclusions especially in the high stress regions that the part will experience in service.

scholarly journals Factors Influencing Physical and Technical Variability in the English Premier League

2015 ◽  
Vol 10 (7) ◽  
pp. 865-872 ◽  
Author(s):  
Michael D. Bush ◽  
David T. Archer ◽  
Robert Hogg ◽  
Paul S. Bradley
Keyword(s):  
Tracking System ◽  
Contextual Factors ◽  
Physical Parameters ◽  
Large Variability ◽  
Technical Parameters ◽  
Technical Variability ◽  
Factors Influencing ◽  
Premier League ◽  
Per Se ◽  
English Premier League

Purpose:To investigate match-to-match variability of physical and technical performances in English Premier League players and quantify the influence of positional and contextual factors.Methods:Match data (N = 451) were collected using a multicamera computerized tracking system across multiple seasons (2005–06 to 2012–13). The coefficient of variation (CV) was calculated from match to match for physical and technical performances in selected positions across different match contexts (location, standard, and result).Results:Wide midfielders demonstrated the greatest CVs for total distance (4.9% ± 5.9%) and central midfielders the smallest (3.6% ± 2.0%); nevertheless, all positions exhibited CVs <5% (P > .05, effect size [ES] 0.1–0.3). Central defenders demonstrated the greatest CVs and wide midfielders the lowest for both high-intensity running (20.2% ± 8.8% and 13.7% ± 7.7%, P < .05, ES 0.4–0.8) and sprint distance (32.3% ± 13.8% and 22.6% ± 11.2%, P < .05, ES 0.5–0.8). Technical indicators such as tackles (83.7% ± 42.3%), possessions won (47.2% ± 27.9%), and interceptions (59.1% ± 37.3%) illustrated substantial variability for attackers compared with all other positions (P < .05, ES 0.4–1.1). Central defenders demonstrated large variability for the number of times tackled per match (144.9% ± 58.3%) and passes attempted and received compared with other positions (39.2% ± 17.5% and 46.9% ± 20.2%, P < .001, ES 0.6–1.8). Contextual factors had limited impact on the variability of physical and technical parameters.Conclusions:The data demonstrate that technical parameters varied more from match to match than physical parameters. Defensive players (fullbacks and central defenders) displayed higher CVs for offensive technical variables, while attacking players (attackers and wide midfielders) exhibited higher CVs for defensive technical variables. Physical and technical performances are variable per se regardless of context.

Inelastic seismic shear amplification due to higher mode effects in reinforced concrete coupled walls

2021 ◽  
pp. 875529302110533
Author(s):  
Gabriel Rivard ◽  
Steeve Ambroise ◽  
Patrick Paultre
Keyword(s):  
Reinforced Concrete ◽  
Parametric Study ◽  
Numerical Study ◽  
Plastic Hinge ◽  
Experimental Studies ◽  
Physical Parameters ◽  
Intensity Level ◽  
Shear Forces ◽  
Coupled Walls ◽  
Seismic Shear

Recent numerical and experimental studies on reinforced concrete shear walls and coupled walls have shown shear forces greater than expected when the walls are subjected to earthquakes at an intensity level that does not exceed the design values. This amplification of shear forces is attributable to the effects of higher modes after the walls develop a plastic hinge at the base. These effects have been recently recognized in North American design codes for cantilever walls and is currently neglected in the design of ductile coupled walls. As part of the research program described in this article, a parametric study was carried out on coupled wall systems to identify the geometric and physical parameters having the greatest influence on the seismic shear amplification. Using the results of this parametric study, an extensive numerical study was conducted on classes of ductile coupled walls subjected to seismic excitation representative of Western and Eastern Canada. This extensive study led to the establishment of shear amplification prediction equations for use in building codes.

Influence of Basic Parameters for Fiber Reinforced Polymer Crushing Simulation

2016 ◽  
Author(s):  
Benoit Stalin ◽  
Dongyang Yang ◽  
Yong Xia ◽  
Qing Zhou
Keyword(s):  
Finite Element ◽  
Mesh Size ◽  
Fiber Reinforced Polymer ◽  
Physical Parameters ◽  
Large Element ◽  
Fiber Reinforced ◽  
Time Step ◽  
Reinforced Polymer ◽  
Simulation Results ◽  
The Impact

This article investigates the influence of finite element model features on Fiber Reinforced Polymer (FRP) crushing simulation results. The study focuses on two composite material tube models using single shell modeling approach. The chosen material model is MAT58 (*MAT_LAMINATED_COMPOSITE_FABRIC) from the commercial finite element analysis software LS-Dyna. The baseline models geometry and material parameters come from a model calibration conducted for lightweight vehicle investigation. Five parameters are investigated. The mesh size and the number of integration point (NIP) are generic and ERODS, TSIZE and SOFT are the non-physical parameters of MAT58. This analysis aims at discuss the influence of these parameters on the simulation results focusing on the initial force peak and the average crush load, regarding results realism and instabilities such as large elements deformation and abnormal peak values. Also, the impact of the number of CPUs involved in the simulation calculation is presented. Recommendations are given to set the mesh size and the NIP. TSIZE value should be selected regarding the simulation time step. On the other hand, ERODS has to be adjusted manually. Both are determinant for simulation robustness. Further studies are proposed to find out the reasons of large element deformation.

MOCUM Code Verification and Sensibility Study Using C5G7 Benchmark

2016 ◽  
Author(s):  
Xue Yang ◽  
Rajan Borse ◽  
Nader Satvat
Keyword(s):  
Method Of Characteristics ◽  
Polar Angle ◽  
Mesh Size ◽  
Sensitivity Study ◽  
High Accuracy ◽  
Benchmark Problem ◽  
Code Verification ◽  
Heterogeneous Effects ◽  
Speed Up ◽  
Better Than

This work uses the 2-D C5G7 benchmark to verify the accuracy of the MOCUM code, a parallel neutronics program based on the method of characteristics (MOC) for solving arbitrary core geometry. Compared to the MCNP results, MOCUM k-eff, maximum assembly and pin power percentage errors are 0.02%, −0.06%, and 0.64%, respectively. The results demonstrate the high accuracy of the MOCUM code. The calculation uses a total of 56 threads, and the runtime on dual Intel Xeon E5-2699 v3 CPUs is 26 minutes, with speed up higher than 50 times. The sensitivity study of various MOC parameters using the calculation of the C5G7 benchmark problem is also performed. The study reveals that C5G7 requires the usage of 48 or more azimuthal angles. The strong flux gradient and the heterogeneous effects need fine unstructured meshes to resolve. The simulation uses 258 million zones with an average mesh size of 0.016 cm2. The investigation of the polar angle quadrature indicates that Leonard polar angle performs slightly better than Gauss-Legendre and Tabuchi polar angles and more than three polar angles are not necessary. In addition, parameter sensitivity study shows that coarse parameters are prone to introduce error to the neutron flux but not k-eff.

Sensitivity Study of Material Input Data on FE Forming Results for Wrinkling and Shearing of Fiber Reinforced Thermoplastic Parts

2019 ◽  
Vol 809 ◽  
pp. 500-505
Author(s):  
Bernd Engel ◽  
Jasmin Graef
Keyword(s):  
Input Data ◽  
Test Procedure ◽  
Material Model ◽  
Sensitivity Study ◽  
Bending Test ◽  
Fiber Reinforced ◽  
Forming Process ◽  
Bias Extension ◽  
Reinforced Thermoplastics ◽  
Material Input

This work presents the analysis of the influence of several material input data to the FE results of the forming process of fiber reinforced thermoplastics within a sensitivity study. The *Fabric material model of Abaqus/Explicit is used for the description of the shear, tensile and compression behavior. It is a test-data based model. The bending behavior will be modeled with beam elements. The interaction between input data will be analyzed and its influence onto the FE forming results and FE analysis of material tests like bias-extension-test, compression and bending test with focus on interactions of input data and test procedure itself.

scholarly journals Simulation of Fragmentation Characteristics of Projectile Jacket Made of Tungsten Alloy after Penetrating Metal Target Plate using SPH Method

2019 ◽  
Vol 69 (6) ◽  
pp. 591-598 ◽  
Author(s):  
Chun Cheng ◽  
Zhonghua Du ◽  
Xi Chen ◽  
Lizhi Xu ◽  
Chengxin Du ◽  
...  
Keyword(s):  
Impact Velocity ◽  
Maximum Tensile Stress ◽  
Calculation Model ◽  
Tungsten Alloy ◽  
Metal Target ◽  
Target Plate ◽  
Average Mass ◽  
Particle Hydrodynamics ◽  
Sph Model ◽  
The Impact

A smooth particle hydrodynamics (SPH) model was used to simulate the fragmentation process of the jacket during penetrator with lateral efficiency (PELE) penetrating the metal target plate to study the fragmentation characteristics of PELE jacket made of tungsten alloy. The validity of the SPH model was verified by experimental results. Then the SPH model was used to simulate the jacket fragmentation under different impact velocity and thickness of target plate. The influence of impact velocity and thickness of target plate on the jacket fragmentation was obtained by analysing the mass distribution and quantity distribution of the fragments formed by the jacket. The results show that the dynamic fragmentation of tungsten alloy can be simulated effectively using the SPH model, Johnson-Cook strength model, maximum tensile stress failure criterion and stochastic failure model. When the thickness of target plate is fixed, the greater the impact velocity, the greater the pressure produced by the projectile impacting the target plate; with the increase of impact velocity, the mass of residual projectile decreases, the number of fragments formed by fragmentation of jacket increases linearly, and the average mass of fragments decreases exponentially. When the impact velocity is constant, the greater the thickness of the target plate, the longer the pressure duration by the projectile impacting the target plate; with the increase of the thickness of target plate, the mass of residual projectile decreases, the number of fragments formed by fragmentation of jacket increases linearly, and the average mass of fragments decreases exponentially. The numerical calculation model and research method adopted in this paper can be used to study the impact fragmentation of solid materials effectively.

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