New Approaches for Identifying Structural Models

1995 ◽  
Author(s):  
Scott Cogan ◽  
Gérard Lallement ◽  
Laetitia Sanseigne
Keyword(s):  
Finite Element ◽  
Research Work ◽  
Structural Models ◽  
Test Preparation ◽  
Finite Element Models ◽  
Structural Modifications ◽  
Additional Information ◽  
Recent Developments ◽  
Selective Sensitivity

Abstract The present synthesis highlights the recent developments in the research work at the R.C.A.M.L. concerning the difficulties encountered at various stages of the correcting process of linear elastodynamics finite element models and some of the solutions suggested to reduce them : optimizing test preparation, combining the principle of selective sensitivity with the concept of pseudo-tests, utilizing additional information coming from base excitations, quantifying the quality of the updated model for applications such as structural modifications or dynamic sub-structuring.

The Collagen Fiber Kinematics in the Anteroinferior Glenohumeral Capsule Are Not Affine-Predicted

2011 ◽  
Author(s):  
Carrie A. Voycheck ◽  
Patrick J. McMahon ◽  
Richard E. Debski
Keyword(s):  
Finite Element ◽  
Structural Model ◽  
Glenohumeral Joint ◽  
Structural Models ◽  
Clinical Problem ◽  
Collagen Fibers ◽  
Material Behavior ◽  
Finite Element Models ◽  
Glenohumeral Ligament ◽  
Glenohumeral Capsule

Glenohumeral dislocation is a significant clinical problem and often results in injury to the anteroinferior (anterior band of the inferior glenohumeral ligament (AB-IGHL) and axillary pouch) glenohumeral capsule. [1] However, clinical exams to diagnose capsular injuries are not reliable [2] and poor patient outcome still exists following repair procedures. [3] Validated finite element models of the glenohumeral capsule may be able to improve diagnostic and repair techniques; however, improving the accuracy of these models requires adequate constitutive models to describe capsule behavior. The collagen fibers in the anteroinferior capsule are randomly oriented [4], thus the material behavior of the glenohumeral capsule has been described using isotropic models. [5,6] A structural model consisting of an isotropic matrix embedded with randomly aligned collagen fibers proved to better predict the complex capsule behavior than an isotropic phenomenological model [7] indicating that structural models may improve the accuracy of finite element models of the glenohumeral joint. Many structural models make the affine assumption (local fiber kinematics follow global tissue deformation) however an approach to account for non-affine fiber kinematics in structural models has been recently developed [8]. Evaluating the affine assumption for the capsule would aid in developing an adequate constitutive model. Therefore, the objective of this work was to assess the affine assumption of fiber kinematics in the anteroinferior glenohumeral capsule by comparing experimentally measured preferred fiber directions to the affine-predicted fiber directions.

scholarly journals STRUCTURAL ASPECTS DURING CONVERSION FROM GENERAL CARGO SHIPS TO CEMENT CARRIERS

Brodogradnja ◽  
2021 ◽  
Vol 72 (2) ◽  
pp. 37-55
Author(s):  
Paul Jurišić ◽  
◽  
Joško Parunov ◽  
Keyword(s):  
Finite Element ◽  
Case Studies ◽  
Thickness Measurement ◽  
Present Condition ◽  
Finite Element Models ◽  
3D Finite Element ◽  
Strength Assessment ◽  
Structural Modifications ◽  
General Cargo ◽  
Structural Aspects

An approach to converting general cargo ship to cement carrier is analysed in the present study, emphasising the structural aspects of the conversion. A comprehensive re-appraisal of the conditions of the ship hull, considering her history and present condition of the structure, is provided. Two case studies are presented where the strength assessment has been performed using 2D sectional and 3D finite element models, generated according to the available hull drawings and thickness measurement reports. The results of the two studies are interpreted with respect to the structural modifications carried out during the conversion process, and some general conclusions are drawn.

Recent Developments in Numerical Modeling of Transduction Materials

1995 ◽  
Author(s):  
Anne-Christine Hladky-Hennion ◽  
Régis Bossut ◽  
Jean-Claude Debus
Keyword(s):  
Finite Element ◽  
Numerical Modeling ◽  
Research Work ◽  
Piezoelectric Composite ◽  
The Finite Element Method ◽  
Theoretical Formulation ◽  
Active Sonar ◽  
Sonar System ◽  
Recent Developments ◽  
Materials Used

Abstract Recent research work in sonar system performance, coupled with achievements in the field of acoustic quieting, has led to the development of new ceramics that are promising for both hydrophone and projector applications. Other materials have also been studied like piezoelectric composite materials, magnetostrictive and electrostrictive materials. To design transducers using these materials, the finite element method seems to be the best suited approach. Using this method, it is possible to analyze, characterize and tailor new materials as well as to design a full transducer or an array. Recent developments in the ATILA finite element code allow the modeling of new transduction materials. The aim of this paper is to present the theoretical formulation in numerical modeling of materials used either for hydrophone or active sonar applications.

Simulation and Analysis on Dynamic Response Characteristics of Six-High Rolling Mill Based on FEM

2012 ◽  
Vol 572 ◽  
pp. 154-159
Author(s):  
Kai Fu Mi ◽  
Jie Zhang ◽  
Hong Bo Li ◽  
Sheng Hui Jia ◽  
Yu Gang Chu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Working Conditions ◽  
Rolling Mill ◽  
Finite Element Method Simulation ◽  
Finite Element Models ◽  
Response Characteristics ◽  
Dynamic Response Characteristics ◽  
Set Up

The vibration influence on the quality of strip for 2180mm six-high cold tandem rolling mill is discussed. The abnormal frequency of mill is analysis by spot examination. The methods of numerical computation and finite element method simulation by the ANSYS are adopted to set up dynamic model of six-high mill. At the same time, the natural frequency of mill and the response to mill at different excitation is calculated. Comparing the analysis results with the data from the experiment, the finite element models presented in the thesis were proved to be an efficient and valid way to simulate actual working conditions.

Analytical Study of Appropriate Design for High-Grade Induction Bend Pipes Subjected to Large Ground Deformation

2004 ◽  
Vol 126 (4) ◽  
pp. 376-383 ◽  
Author(s):  
Hiroshi Yatabe ◽  
Naoki Fukuda ◽  
Tomoki Masuda ◽  
Masao Toyoda
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Analytical Study ◽  
Ground Deformation ◽  
Bending Moment ◽  
Finite Element Models ◽  
High Grade ◽  
Buried Pipeline ◽  
Parametric Studies

In order to clarify the significant parameters to control the deformability of high-grade induction bend pipes, finite element analyses simulating the deformation behavior subjected to an internal pressure and bending moment were carried out. Parametric studies were conducted using the finite element models with various mechanical properties and geometric imperfections. The change in the integrity of the buried pipeline due to the quality of the induction bend pipe was then quantitatively examined. Consequently, this study indicated that the mechanical properties, the dimensions and tolerance and the properties of the “transition” part should be appropriately designed in proportion to the ground deformation.

Prediction Capabilities of Damped Updated Finite Element Models

2011 ◽  
Author(s):  
Vikas Arora
Keyword(s):  
Finite Element ◽  
Model Updating ◽  
Dynamic Properties ◽  
Detailed Comparison ◽  
Element Model ◽  
Mode Shapes ◽  
Finite Element Models ◽  
Complex Frequency ◽  
Structural Modifications ◽  
The Finite Element Model

Model updating techniques are used to correct the finite element model of a structure using experimental data such that the updated model more correctly describes the dynamic properties of the structure. One of the applications of such an updated model is to predict the effects of making modifications to the structure. These modifications may be imposed by design alterations for operating reasons. Most of the model updating techniques neglect damping and so these updated models can’t be used for accurate prediction of complex frequency response functions (FRFs) and complex mode shapes. In this paper, a detailed comparison of prediction capabilities of parameter-based and non parameter-based damped updated methods for structural modifications is done. The suitability of paramter-based and non parameter-based damped updated models for predicting the effects of structural modifications is evaluated by laboratory experiment for the case of an F-shape test structure. It is concluded that parameter-based damped updated models are likely to perform better in predicting the effects of structural modifications.

Fuselage Structural-Acoustic Modeling for Structure-Borne Interior Noise Transmission

1988 ◽  
Vol 110 (2) ◽  
pp. 226-233 ◽  
Author(s):  
J. F. Unruh ◽  
S. A. Dobosz
Keyword(s):  
Finite Element ◽  
Structural Models ◽  
Local Area ◽  
Interior Noise ◽  
Acoustic Modeling ◽  
Finite Element Models ◽  
Aircraft Fuselage ◽  
Structural Details ◽  
Noise Transmission ◽  
Structural Definition

Detailed finite element models of a fuselage structure and acoustic cabin volume of a laboratory based prototypical aircraft fuselage were generated for the purpose of studying the predictive capabilities of deterministic modeling procedures for structure-borne noise transmission. Comparative predictions are made to measured wing-to-fuselage attach point inertances and interior noise to force responses. Several structural models with increased structural definition were evaluated. It was found that to accurately predict wing-to-fuselage attach point inertances required increased local area structural definition, while interior noise can be reasonably well predicted without paying additional attention to local area structural details.

A method for performing efficient parametric dynamic analyses in large finite element models undergoing structural modifications

2017 ◽  
Vol 131 ◽  
pp. 625-638 ◽  
Author(s):  
F.J. Herrada ◽  
J. García-Martínez ◽  
A. Fraile ◽  
L.K.H. Hermanns ◽  
F.J. Montáns
Keyword(s):  
Finite Element ◽  
Finite Element Models ◽  
Structural Modifications ◽  
Dynamic Analyses

WiFiMon

2019 ◽  
Vol 8 (1) ◽  
pp. 1-18
Author(s):  
Christos Bouras ◽  
Kurt Baumann ◽  
Vasileios Kokkinos ◽  
Nikolaos Papachristos ◽  
Kostas Stamos
Keyword(s):  
Network Performance ◽  
Research Work ◽  
End Users ◽  
Clear Understanding ◽  
End User ◽  
Additional Information ◽  
Log Files ◽  
Measuring Network ◽  
Network Quality

Measuring network quality of a wireless network as experienced by end-users is quite difficult, as there is not a single tool available that can record measurements on all sides of the system. The approach presented in this research work is based on the end-user feedback, giving the opportunity of visualization of network performance in real time. This paper initially presents an overview of the developed tool, called WiFiMon, which has the ability to capture, record measurements and export statistics on the quality of Wi-Fi network as perceived by the end-users. The measurements are initiated by the end-users—without their intervention—after they visit a webpage or use a mobile application. WiFiMon aims to give a clear understanding of the Wi-Fi network conditions by measuring specific parameters of the network, such as download/upload throughput, and correlate these measurements with raw data from various log files to obtain additional information regarding the performance of specific access points. The results reveal the functionality of the proposed tool and its scalability.

Methodology for Quantitative Error-Assessment of Finite-Element Models

1995 ◽  
Author(s):  
John N. Majerus
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Nonlinear Behavior ◽  
Finite Element Models ◽  
Error Assessment ◽  
The Finite Element Method ◽  
Designed Experiments ◽  
Highly Nonlinear ◽  
Nonlinear Simulations ◽  
Recent Developments

Abstract Although recent developments in adaptivity and rezoning have enhanced the ease and use of the finite element method, the question remains: how good are the resulting simulations? In the case of highly nonlinear behavior, it appears that this question can only be answered by properly designed experiments. One such experiment involves the nonlinear behavior (material, geometry and boundary conditions) associated with a precision closed-die (PCD) forging. This paper presents some PCD data that could not be modeled by one particular FE code-simulation. Hopefully, these data can be used for the quantitative error-assessment of other codes for similar nonlinear simulations. Some possible code-simulation improvements are discussed and recommendations for future experiments are made.

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