Finite element modeling to expand the UMCCA model to describe biofilm mechanical behavior

2005 ◽  
Vol 52 (7) ◽  
pp. 161-166 ◽  
Author(s):  
C.S. Laspidou ◽  
B.E. Rittmann ◽  
S.A. Karamanos
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Finite Element Modeling ◽  
Mechanical Behavior ◽  
Element Model ◽  
Internal Stresses ◽  
Active Biomass ◽  
Biofilm Model ◽  
Composite Solid ◽  
The Finite Element Model

In order to understand the influence of biofilm's physical and microbiological structures on its mechanical behavior, a finite element model that describes the structural mechanics of a composite solid is linked to the outputs of the multi-component biofilm model UMCCA. The UMCCA model outputs densities of active biomass, inert biomass, and EPS for each compartment in a 2-D biofilm. These densities are mapped to the finite-element model to give a composite Young's modulus, which expresses the stress-strain properties of the biofilm by location. Sample results illustrate that using this methodology, one can identify the points in the biofilm that develop the highest internal stresses and that are most likely to fail first, leading to detachment.

Effects of Air Bending Parameters on Spingback Using Finite Element Analysis

2013 ◽  
Vol 423-426 ◽  
pp. 978-983
Author(s):  
Xie Li
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Internal Stresses ◽  
Element Analysis ◽  
Air Bending ◽  
Bending Process ◽  
Punch Radius ◽  
The Finite Element Model

Springback is a common phenomenon in air bending of sheet metal forming, caused by the elastic redistribution of the internal stresses during unloading. It has been recognized that springback is essential for the design of the air bending. Traditionally, the values of springback is obtained for air bending parameters from handbook tables or springback graphs. However, the handbook tables or springback graphs are obtained using experiments and it is a time consuming processes. In this paper, a finite element model has been used to analyze the air bending process. Some experiments are carried out on ST12 materials, and the finite element model is validated comparing with experiments. In the present research the influence of process variables such as punch radius, die radius and die on springback are discussed using finite element analysis. Thus, the presented results of this research provide a basis of design to improve forming quality.

Finite Element Analysis of Head-Form Impacting Laminated Glass for Automotive Windscreens

2016 ◽  
Vol 680 ◽  
pp. 72-75
Author(s):  
Yan Min ◽  
Zeng Chen Cao ◽  
Shuang Li
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Mechanical Behavior ◽  
Element Model ◽  
Laminated Glass ◽  
Element Analysis ◽  
Head Form ◽  
Set Up ◽  
The Finite Element Model

Based on GB/T 5137.1-2002 experiment specification, the finite element model of head-form impacting laminated glass for automotive windscreens is set up in this paper. According to Finite Element Analysis results of laminated glass with different structure and further analyzing impact property and mechanism of laminated glass , the influence rule of the structure of the laminated glass on the mechanical behavior is discussed. (H)

scholarly journals Analytical and Finite Element Modeling of the Dynamic Characteristics of a Linear Feeding Stage with Different Arrangements of Rolling Guides

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Jyh-Cheng Chang ◽  
Jui-Pin Hung
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Finite Element Model ◽  
Finite Element Modeling ◽  
Dynamic Characteristics ◽  
Element Model ◽  
Linear Guide ◽  
Element Modeling ◽  
Positioning Stage ◽  
The Finite Element Model

This study was aimed at investigating the dynamic behaviors of the linear driven feeding stage by means of the analytical and finite element modeling approaches. To assess the dynamic characteristics of the stages with different linear guide arrangements, the finite element model of the stages was created, in which the linear components with rolling interface were accurately modeled based on the Hertzian theory. On the other hand, the analytically mathematical model was derived to determine how the linear guide arrangement affects the dynamic characteristics of the stage. Results of the modal analysis show that the vibration behaviors of the positioning stage are dominated by the rigidity of the linear components and the platform. In addition, comparisons of the results from the two approaches further indicate that the platform rigidity is an important factor determining the accuracy of the prediction of the vibration frequencies by the analytically mathematical model. As a conclusion of the study, the analytically mathematical model can approximate well to the finite element model when the linear stage is designed with appropriate structure rigidity.

Finite Element Modeling Method of 3D Braided Composites Based on ICT Technique

2012 ◽  
Vol 236-237 ◽  
pp. 16-20
Author(s):  
Shu Yong Wang ◽  
Jian Fu ◽  
Qian Li Wang
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Composite Materials ◽  
Finite Element Model ◽  
Finite Element Modeling ◽  
Element Model ◽  
Braided Composites ◽  
Element Modeling ◽  
3D Braided Composites ◽  
The Finite Element Model

A finite element modeling method based on industrial computed tomography (ICT) technique is proposed to address the insufficient accuracy of traditional grinding method for the meso-structure analysis of composite materials. In this method, the slice images of 3D composites are first acquired by ICT technique. And then, the internal meso-structure images of composite materials are obtained through the digital image processing to the slice images. Finally the meso-structure images are converted to vector format and inputted ANSYS to build the finite element model for the analysis of the mechanical properties. The experimental results show that this method can establish the finite element model and reveal the internal structure and the inherent mechanical properties of composite materials. These researches provide a reference for the manufacture processing of 3D braided composites, and the theoretical basis for the optimal design and performance evaluation. It would be of significance for the improvement of the composites mechanical properties.

Prediction of peen forming stress and plate deformation with a combined method

2019 ◽  
Vol 233 (14) ◽  
pp. 2492-2504 ◽  
Author(s):  
Xudong Xiao ◽  
Yao Sun ◽  
Xin Tong ◽  
Yan Li ◽  
Guoqiang Gao
Keyword(s):  
Finite Element ◽  
Stress Field ◽  
Finite Element Model ◽  
Element Model ◽  
Internal Stresses ◽  
Single Shot ◽  
Forming Parameters ◽  
Peen Forming ◽  
Computational Resources ◽  
The Finite Element Model

To simulate the deformations of the strip peen formed plate more realistic, and using low computational resources, a strategy combining analytical and finite element methods is proposed in this article. First, the internal stresses in the target induced by single shot impact are calculated with expanding cavity model. Second, the stress field of single shot impact is used to derive the stress field of multiple shot impacts by considering the overlaps of adjacent shot impacts. Third, the calculated stress field is introduced to the finite element model to obtain the resultant shape of the plate. The shot dimple distribution in reality is detected and fitted with normal distribution function. The random distribution of the positions of shot impacts is involved in the simulation to make the simulation more realistic. In the finite element model, the plate is modeled with shell element to reduce the demand of the computational resources. The simulated shapes of the plate under different peen forming parameters are compared with the scanned three-dimensional experimental shapes with the same forming parameters. The comparison shows that the simulated shapes are in good agreement with the experiments.

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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