Parametric analysis of composite sinusoidal specimens under quasi-static crushing

2018 ◽  
Vol 122 (1254) ◽  
pp. 1244-1262 ◽  
Author(s):  
H. L. Mou ◽  
X. Su ◽  
J. Xie ◽  
Z. Y. Feng
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Parametric Analysis ◽  
Goodness Of Fit ◽  
Element Model ◽  
Response Surfaces ◽  
Numerical Results ◽  
Surface Model ◽  
Selection Scheme ◽  
The Finite Element Model

ABSTRACTThis paper aims to build the finite element model of the composite sinusoidal specimens and to carry out the parametric analysis. In this paper, the damage behaviour and the energy-absorbing results of composite sinusoidal specimens have been studied by quasi-static crushing experiments. The failure mechanisms of specimens under quasi-static crushing is further analysed. A numerical simulation has been performed by using the finite element model code LS-DYNA. The numerical results, in terms of load -displacement data, have been compared against experimental data, and good agreement has been found. Moreover, a sensitivity study has been carried out by varying material properties in order to assess their influence on the numerical results, and the material parameter selection scheme is optimised based on the constructed corresponding response surfaces. The results show that the response surface model has passed the test of goodness of fit, and the optimisation method can effectively assist the finite element modelling, and greatly decrease the numbers of trial and error.

scholarly journals Variable Stiffness Design and Multiobjective Crashworthiness Optimization for Collision Post of Subway Cab Cars

Machines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 246
Author(s):  
Wei Guo ◽  
Ping Xu ◽  
Zhaofeng Yi ◽  
Jie Xing ◽  
Hui Zhao ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Response Surface ◽  
Energy Absorption ◽  
Pareto Frontier ◽  
Variable Stiffness ◽  
Element Model ◽  
Surface Model ◽  
Front End ◽  
The Finite Element Model

This paper proposes a variable stiffness collision post (VSCP) structure based on a uniform stiffness collision post (USCP) structure and performs stiffness matching optimization for VSCPs. A collision post structure assembled in a subway front-end frame can maintain the living space and absorb a certain amount of the kinetic energy of an impact. The experiment was applied on USCP, and the finite element model was verified experimentally. To investigate the effects of the stiffness parameters of VSCP on the specific energy absorption response (SEA_VSCP) and the area of intrusion response (S_In), response surface models fitted from design of experiment were adopted with the finite element model. In addition, a multiobjective optimization design was realized by using the global response search method and a Pareto frontier sequence was generated, which was based on the developed response surface model. It was found that the optimal value of SEA_VSCP and S_In responses cannot be achieved at the same time. Finally, a grey relational analysis is propounded to attain a desirable balance between SEA_VSCP and S_In from the Pareto frontier sequence under constraints of the peak crash force of VSCP and energy absorption of the front-end of cab car. The optimization result shows that the crashworthiness of VSCP is better than that of USCP.

An Efficient Method for Predicting Fracture of Hard Food Source

2008 ◽  
Author(s):  
Nirdesh D. Patel ◽  
Ian Grosse ◽  
Dan Sweeney ◽  
David S. Strait ◽  
Peter W. Lucas ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Food Item ◽  
Food Source ◽  
Element Model ◽  
Bite Force ◽  
Tooth Surface ◽  
Surface Model ◽  
Physical Testing ◽  
The Finite Element Model

In this paper we present a fast and reliable method for estimating the bite force required to fracture hard foods. The process involves complementary physical testing and finite element modeling. For physical testing, metal castings of upper or lower teeth are prepared. Metal tooth castings are mounted on a pivoting fixture interfaced to an Instron machine to simulate bite mechanics and thus to fracture hard food specimens. For the finite element model the tooth surfaces are modeled as rigid surface bodies in a nonlinear multi-load step contact analysis, while the food item is modeled as an elastic body. However, because only tooth surface information is needed in the model, we are able to automatically develop the geometry of the tooth surface using a tactile digitizing stylus with stereo lithographic surface profile information directly exported and subsequently imported into the FEA tool. We therefore avoid the need to laser scan tooth geometry which introduces significant “noise” into the surface model representation that must be painstakingly “cleaned” manually using software tools. The physical testing provides the force required to fracture the food item, while the finite element model provides the complete stress and strain state of the food item at the moment of fracture. Using this approach we have simulated the tooth biting mechanics of fossil primates to estimate biting force required to initiate a crack in a hard food source such as a macadamia nut. These analyses are designed to measure how occlusal morphology affects feeding performance, as the bite force needed to initiate a crack may vary according to tooth shape. The bite forces found using this approach will be used as an input for full-skull finite element models of early hominids (extinct fossil relatives of humans). The results of this work will be useful in testing the hypothesis that derived craniodental features in some of these hominids are adaptations for feeding on hard, brittle, seasonally available foods.

scholarly journals Rotational Restraint to Purlins Provided by Standing Seam Roof Systems

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Qin Yang ◽  
Wei Luan ◽  
Shaole Yu ◽  
Junjie Chen
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Parametric Analysis ◽  
Element Model ◽  
Local Deformation ◽  
Rotational Restraint ◽  
Restraint Mechanism ◽  
Roof Panel ◽  
Panel Thickness ◽  
The Finite Element Model

The finite element model used for analyzing the rotational restraint rigidity of standing seam roof systems was developed. The influences of different factors on the rotational restraint rigidity provided by two types of standing seam roof systems were studied. The variables include local deformation of standing seam roof panels, panel thickness, clip tab thickness, and the relative sliding of clip tab and clip base. The restraint mechanism of standing seam roof systems to the purlins was studied. It is shown that the rotational restraint rigidity provided by the two types of researching standing seam roof systems mainly depends on the slide tab thickness and the roof panel thickness. Finally, formulae for calculating rotational restraint rigidity of the LSIII and SS360 standing seam roof systems were also proposed based on parametric analysis results.

The Finite Element Model (FEM) Updating of Mirror Frame System Based on Response Surface Method

2011 ◽  
Vol 291-294 ◽  
pp. 1615-1620
Author(s):  
Xue Qian Chen ◽  
Shi Fu Xiao ◽  
Xin En Liu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Response Surface ◽  
Response Surface Method ◽  
Element Model ◽  
Surface Model ◽  
Surface Method ◽  
Frame System ◽  
Relative Errors ◽  
The Finite Element Model

It is difficult in finite element model(FEM) updating, because the essence is a mechanical anti-question solving. In the paper, the suppositional material method is utilized to model the FEM of a mirror frame system, and the required updating parameters are defined. The functions between the natural frequency and the updating parameters are established based on the response surface method. Based on the response surface model and the modal experiment results, the sum of absolute value of relative errors between the results of experiments and simulations is defined as the optimization objective, four required updating are identified automatically. The first three natural frequencies of updated mirror frame system are better accordant with the experiment results, which proves the method correct and reliable.

VIRTUAL TESTING OF COMPOSITE MOTORCYCLE HELMETS

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1705-1711 ◽  
Author(s):  
ALESSANDRO CERNICCHI ◽  
UGO GALVANETTO ◽  
ROBIN OLSSON
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Numerical Results ◽  
Experimental Results ◽  
Virtual Testing ◽  
Unidimensional Model ◽  
Motorcycle Helmets ◽  
The Finite Element Model

A study about the response of motorcycle helmets to impacts is described in this paper and possible ways to improve current designs are discussed. Firstly, a simple unidimensional model of helmet is analyzed and the main parameters that affect its response are pointed out. Subsequently, the generation and testing of the Finite Element model of a commercially available helmet are described and numerical results are compared to experimental results. Finally, the FE modeled is used to compare different design configurations.

scholarly journals Sensitivity Analysis of the Influence of Structural Parameters on Dynamic Behaviour of Highly Redundant Cable-Stayed Bridges

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
B. Asgari ◽  
S. A. Osman ◽  
A. Adnan
Keyword(s):  
Sensitivity Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Model Updating ◽  
Structural Parameters ◽  
Element Model ◽  
Structural Behavior ◽  
Model Tuning ◽  
The Finite Element Model ◽  
Cable Stayed Bridges

The model tuning through sensitivity analysis is a prominent procedure to assess the structural behavior and dynamic characteristics of cable-stayed bridges. Most of the previous sensitivity-based model tuning methods are automatic iterative processes; however, the results of recent studies show that the most reasonable results are achievable by applying the manual methods to update the analytical model of cable-stayed bridges. This paper presents a model updating algorithm for highly redundant cable-stayed bridges that can be used as an iterative manual procedure. The updating parameters are selected through the sensitivity analysis which helps to better understand the structural behavior of the bridge. The finite element model of Tatara Bridge is considered for the numerical studies. The results of the simulations indicate the efficiency and applicability of the presented manual tuning method for updating the finite element model of cable-stayed bridges. The new aspects regarding effective material and structural parameters and model tuning procedure presented in this paper will be useful for analyzing and model updating of cable-stayed bridges.

Biodynamics of Human Thorax With Body Armors Subject to Bullet Impact

2001 ◽  
Author(s):  
Y. W. Kwon ◽  
J. A. Lobuono
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Body Armor ◽  
Projectile Impact ◽  
Human Thorax ◽  
Trachea And Bronchi ◽  
Armor System ◽  
The Finite Element Model

Abstract The objective of this study is to develop a finite element model of the human thorax with a protective body armor system so that the model can adequately determine the thorax’s biodynamical response from a projectile impact. The finite element model of the human thorax consists of the thoracic skeleton, heart, lungs, major arteries, major veins, trachea, and bronchi. The finite element model of the human thorax is validated by comparing the model’s results to experimental data obtained from cadavers wearing a protective body armor system undergoing a projectile impact.

Dynamic Analysis of a Turbocharger Centrifugal Compressor Impeller

1991 ◽  
Author(s):  
V. Ramamurti ◽  
D. A. Subramani ◽  
K. Sridhara
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Centrifugal Compressor ◽  
Element Model ◽  
Simplified Model ◽  
Cyclic Symmetry ◽  
Compressor Impeller ◽  
Cyclic Symmetric ◽  
The Finite Element Model

Abstract Stress analysis and determination of eigen pairs of a typical turbocharger compressor impeller have been carried out using the concept of cyclic symmetry. A simplified model treating the blade and the hub as isolated elements has also been attempted. The limitations of the simplified model have been brought out. The results of the finite element model using the cyclic symmetric approach have been discussed.

Analysis of Effective Pre-Stress of Continuous Rigid Frame Bridge in Service Based on Inversion Theory

2013 ◽  
Vol 671-674 ◽  
pp. 1012-1015
Author(s):  
Zhao Ning Zhang ◽  
Ke Xing Li
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Inversion Method ◽  
Vertical Deflection ◽  
Continuous Rigid Frame Bridge ◽  
Rigid Frame ◽  
Inversion Theory ◽  
Rigid Frame Bridge ◽  
The Finite Element Model

Due to the environment, climate, loads and other factors, the pre-stress applied to the beam is not a constant. It is important for engineers to track the state of the pre-stress in order to ensure security of the bridge in service. To solve the problem mentioned above, the paper puts forward a new way to analyze the effective pre-stress using the displacement inversion method based on the inversion theory according to the measured vertical deflection of the bridge in service at different time. The method is a feasible way to predict the effective pre-stress of the bridge in service. Lastly, taking the pre-stressed concrete continuous rigid frame bridge for example, the effective pre-stress is analyzed by establishing the finite element model.

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