The prediction of vehicle vibration transmitted to the occupant using a modular transfer matrix

2021 ◽  
pp. 107754632199759
Author(s):  
Jianchun Yao ◽  
Mohammad Fard ◽  
John L Davy ◽  
Kazuhito Kato
Keyword(s):  
Finite Element ◽  
Transfer Matrix ◽  
Dynamic Performance ◽  
Complex Structure ◽  
Vehicle Body ◽  
Computational Time ◽  
Accurate Estimation ◽  
Finite Element Models ◽  
Transfer Matrices ◽  
Body Vibration

Industry is moving towards more data-oriented design and analyses to solve complex analytical problems. Solving complex and large finite element models is still challenging and requires high computational time and resources. Here, a modular method is presented to predict the transmission of vehicle body vibration to the occupants’ body by combining the numerical transfer matrices of the subsystems. The transfer matrices of the subsystems are presented in the form of data which is sourced from either physical tests or finite element models. The structural dynamics of the vehicle body is represented using a transfer matrix at each of the seat mounting points in three triaxial (X–Y–Z) orientations. The proposed method provides an accurate estimation of the transmission of the vehicle body vibration to the seat frame and the seated occupant. This method allows the combination of conventional finite element analytical model data and the experimental data of subsystems to accurately predict the dynamic performance of the complex structure. The numerical transfer matrices can also be the subject of machine learning for various applications such as for the prediction of the vibration discomfort of the occupant with different seat and foam designs and with different physical characteristics of the occupant body.

An accurate estimation of bone density improves the accuracy of subject-specific finite element models

2008 ◽  
Vol 41 (11) ◽  
pp. 2483-2491 ◽  
Author(s):  
Enrico Schileo ◽  
Enrico Dall’Ara ◽  
Fulvia Taddei ◽  
Andrea Malandrino ◽  
Tom Schotkamp ◽  
...  
Keyword(s):  
Finite Element ◽  
Bone Density ◽  
Accurate Estimation ◽  
Finite Element Models ◽  
Subject Specific

Structural Abstraction in Snap-fit Analysis

2000 ◽  
Vol 122 (4) ◽  
pp. 395-402 ◽  
Author(s):  
Gaurav Suri ◽  
Anthony F. Luscher
Keyword(s):  
Finite Element ◽  
Accurate Estimation ◽  
Test Cases ◽  
Finite Element Models ◽  
Feature Models ◽  
Engineering Activity ◽  
End Conditions ◽  
Unrealistic Assumption ◽  
Fixed End ◽  
Plastic Parts

Snap-fit design has always been more of an art instead of an engineering activity. Research in this area focuses on generating finite element models for predicting the performance of snap-fit features. Such research typically uses fixed-end conditions at the base of the snap-fit feature. Often this is an unrealistic assumption, because snap-fits are usually molded on plastic parts with significant flexibility. The performance of snap-fits can be significantly influenced by this additional flexibility. To predict this performance of snap-fits it often becomes necessary to analyze the entire part, which can be a costly and time consuming process. There is no general methodology in the open literature to incorporate base-part flexibility into the design of snap-fit features. Existing work in this area is inaccurate and limited to certain base-part and snap-fit topologies. This paper proposes a new methodology called structural abstraction for incorporating base-part flexibility into snap-fit feature models. This methodology abstracts base-parts as spring elements with various stiffnesses. The underlying theory and the relevant relationships are developed and the approach is validated using several test cases. Independence of the approach to both base-part and snap-fit topologies is established and shown to be a major advantage of this technique. Use of this methodology will improve snap-fit analysis and give a more accurate estimation of retention strength. It is shown that in certain cases the improvement in accuracy over conventional finite element models of snap-fits can be as high as 70 percent. [S1050-0472(00)02504-6]

scholarly journals Study on Side Collision of Battery Boxes Based on HyperWorks

2021 ◽  
Vol 2137 (1) ◽  
pp. 012012
Author(s):  
Weigao Qiao ◽  
Zhanxi Zhang ◽  
Dong Lu ◽  
Lei Yu
Keyword(s):  
Finite Element ◽  
Internal Energy ◽  
Electric Vehicles ◽  
Lateral Acceleration ◽  
Vehicle Body ◽  
Finite Element Models ◽  
Before And After ◽  
Two Measures ◽  
Groove Structure ◽  
Side Collision

Abstract To effectively improve the safety of battery boxes in side collision of electric vehicles, two measures are proposed: Firstly spread the boss evenly around the battery box. Secondly the upper and lower parts of the battery box are matched with the convex heads and groove structure. The finite element models of the battery boxes before and after the optimization, the vehicle and the movable barrier are established in this paper. According to the collision regulations, the side collision simulation of the vehicle body is carried out. The changes of the stress, deformation and lateral acceleration of the battery boxes are analyzed. The effectiveness of the measures is verified. The extrusion models of the battery boxes are established. The deformation and the changes of the internal energy of the battery boxes are analyzed. The effectiveness of the measures is verified again.

scholarly journals Sensitivity of Intervertebral Disc Finite Element Models to Internal Geometric and Non-geometric Parameters

2021 ◽  
Vol 9 ◽  
Author(s):  
Yuekang Du ◽  
Saman Tavana ◽  
Tamanna Rahman ◽  
Nicoleta Baxan ◽  
Ulrich N. Hansen ◽  
...  
Keyword(s):  
Finite Element ◽  
Intervertebral Disc ◽  
Material Properties ◽  
Fibre Bundle ◽  
Complex Geometry ◽  
Compressive Loading ◽  
Computational Time ◽  
Finite Element Models ◽  
Model Response ◽  
Modelling Approaches

Finite element models are useful for investigating internal intervertebral disc (IVD) behaviours without using disruptive experimental techniques. Simplified geometries are commonly used to reduce computational time or because internal geometries cannot be acquired from CT scans. This study aimed to (1) investigate the effect of altered geometries both at endplates and the nucleus-anulus boundary on model response, and (2) to investigate model sensitivity to material and geometric inputs, and different modelling approaches (graduated or consistent fibre bundle angles and glued or cohesive inter-lamellar contact). Six models were developed from 9.4 T MRIs of bovine IVDs. Models had two variations of endplate geometry (a simple curved profile from the centre of the disc to the periphery, and precise geometry segmented from MRIs), and three variations of NP-AF boundary (linear, curved, and segmented). Models were subjected to axial compressive loading (to 0.86 mm at a strain rate of 0.1/s) and the effect on stiffness and strain distributions, and the sensitivity to modelling approaches was investigated. The model with the most complex geometry (segmented endplates, curved NP-AF boundary) was 3.1 times stiffer than the model with the simplest geometry (curved endplates, linear NP-AF boundary), although this difference may be exaggerated since segmenting the endplates in the complex geometry models resulted in a shorter average disc height. Peak strains were close to the endplates at locations of high curvature in the segmented endplate models which were not captured in the curved endplate models. Differences were also seen in sensitivity to material properties, graduated fibre angles, cohesive rather than glued inter-lamellar contact, and NP:AF ratios. These results show that FE modellers must take care to ensure geometries are realistic so that load is distributed and passes through IVDs accurately.

Improving finite element results in modeling heart valve mechanics

2018 ◽  
Vol 232 (7) ◽  
pp. 718-725 ◽  
Author(s):  
Emily Earl ◽  
Hadi Mohammadi
Keyword(s):  
Finite Element ◽  
Heart Valve ◽  
Numerical Technique ◽  
Strain Tensor ◽  
Computational Cost ◽  
Constitutive Models ◽  
Least Square ◽  
Computational Time ◽  
Finite Element Models ◽  
Fine Mesh

Finite element analysis is a well-established computational tool which can be used for the analysis of soft tissue mechanics. Due to the structural complexity of the leaflet tissue of the heart valve, the currently available finite element models do not adequately represent the leaflet tissue. A method of addressing this issue is to implement computationally expensive finite element models, characterized by precise constitutive models including high-order and high-density mesh techniques. In this study, we introduce a novel numerical technique that enhances the results obtained from coarse mesh finite element models to provide accuracy comparable to that of fine mesh finite element models while maintaining a relatively low computational cost. Introduced in this study is a method by which the computational expense required to solve linear and nonlinear constitutive models, commonly used in heart valve mechanics simulations, is reduced while continuing to account for large and infinitesimal deformations. This continuum model is developed based on the least square algorithm procedure coupled with the finite difference method adhering to the assumption that the components of the strain tensor are available at all nodes of the finite element mesh model. The suggested numerical technique is easy to implement, practically efficient, and requires less computational time compared to currently available commercial finite element packages such as ANSYS and/or ABAQUS.

scholarly journals Application of Optimization Based Finite Element Model Updating Method On 3d Printed Model Structures

2019 ◽  
Author(s):  
Mohammed Kashama Guzunza ◽  
Ozgur Ozcelik ◽  
Umut Yucel ◽  
Ozgur Girgin
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Model Updating ◽  
Complex Structure ◽  
Element Model ◽  
Initial Structure ◽  
Finite Element Models ◽  
3D Printed ◽  
Building System ◽  
Shear Building

Nowadays it becomes trend in studying of dynamic behavior on complex structure. Model updating is one of the tools developed for verifying accuracy of finite element models. In this paper, method for computing model updating on finite element model and effective the experimental modal analysis of structural systems is developed. The identification method developed in this study is based on time-domain system identification numerical techniques. The case study considered in this work is a 3D printed structure that be modeled as a two-story shear building system with irregular torsion. A preliminary numerical model of the two-story shear building system is developed by using SAP2000 and the experimental modal parameters data are collected in the laboratory buy some test then are modeled by Artemis modal pro. After obtaining the results from numerical modal and experimental modal, it was brought to FEMtools software to improve the match between the dynamic properties of an initial structure and the experimentally estimated modal data for updating. After updating, it’s shown that optimization was done, that some unknown material parameters (such as mass density and young modulus) of materials and/or boundary conditions were optimized by FEMtools Optimization that provides the possibility to perform design optimization on updated finite element models.

The Analysis of Line Structures by Transfer Matrices Derived from Finite Elements

1975 ◽  
Vol 19 (01) ◽  
pp. 57-61
Author(s):  
W. D. Pilkey ◽  
J. K. Haviland ◽  
P. Y. Chang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Elements ◽  
Transfer Matrix ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Large Scale ◽  
The Finite Element Method ◽  
Transfer Matrices ◽  
Finite Element Systems

It is shown that the finite-element method can be efficiently employed in the analysis of line structures, in particular, ship structures, if it is combined with the transfer matrix method. Advantage is taken of the finite element method's structural modeling capability in representing complicated substructures. The substructures are pieced together along the length of the structure using transfer matrices. It is demonstrated that this approach can be superimposed on available large scale finite-element systems to improve their efficiency and increase their capabilities.

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