Automated Finite Element Modeling of Tube Frame Structure Parametric Design

2002 ◽  
Author(s):  
Robert R. Mayer ◽  
Ashok Vaishnav
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Model Building ◽  
Parametric Design ◽  
Finite Element Mesh ◽  
Frame Structure ◽  
Finite Element Models ◽  
Element Mesh ◽  
Element Modeling ◽  
Finite Element Meshes

This research was intended to address the last step in the development of a tube-frame (termed B2B) parametric crashworthiness model - automated finite element modeling of the parametric design. We have added the generation of finite element models to the previously built Unigraphics Version 16 (UG V16) parametric model, so that finite element models could be quickly built. UG/WAVE was used to design the vehicle parametrically and UG/SCENARIO, a pre- and post-processor integrated in UG, was used to automatically construct the finite element mesh. We established the quality of the finite element meshes, generated for two new designs, which were created by changing overall dimensions of the vehicle. This was done using objective criteria for the finite element mesh. The component data was added to the automatically generated mesh, and the results from the crashworthiness analysis of this model compared favorably with the ‘hand-built’ model using traditional model building techniques. The results from this work will be useful in the development of the parametric design process. The use of automatically generated finite element meshes will also be useful for the automated evaluation of these parametric designs.

Finite Element Modeling for Optimizing Hermetic Package Reliability

1989 ◽  
Vol 111 (4) ◽  
pp. 255-260 ◽  
Author(s):  
J. H. Lau ◽  
L. B. Lian-Mueller
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Optimal Design ◽  
Thermal Behavior ◽  
Finite Element Modeling ◽  
Thermal Stresses ◽  
Finite Element Models ◽  
The Finite Element Method ◽  
Element Modeling ◽  
Package Reliability

The thermal stresses in microwave packages are studied by the finite element method. Emphasis is placed on the effects of material construction and design on the reliability of very small hermetic packages. Three different microwave packages have been designed and six finite element models (two for each design) have been analyzed. To verify the validity of the finite element results, some leak tests have been performed and the results agree with the analytical conclusions. The results presented herein should provide a better understanding of the thermal behavior of hermetic packages and should be useful for their optimal design.

Finite Element Modeling and Analysis of Structural Joints Using Nuts and Bolts

2011 ◽  
Author(s):  
Prasannakumar S. Bhonge ◽  
Brian D. Foster ◽  
Hamid M. Lankarani
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Finite Element Modeling ◽  
Joint Modeling ◽  
3D Models ◽  
Element Mesh ◽  
Static Tests ◽  
Modeling And Analysis ◽  
Element Modeling ◽  
Double Shear

The majority of the structural failures of mechanical structures and systems are found in joints rather than continuous material. Joints have historically consisted of assemblies involving nuts, bolts, screws, etc. and the design and analysis of these joints can be quite challenging. This work provides two baselines on the finite element modeling (FEM) methods and analysis of a nut and bolt joint. The first baseline involves a basic modeling method using linear calculation of 2D plates and bar elements, and the second baseline involves one of the more complex methods using non-linear calculation of 3D solids. The two methods are described for modeling of a joint for two test conditions, namely the double shear joint in tension with two different bolt sizes and two plate thicknesses. First, the simplified method of rigid elements and equivalent strength beam elements is considered. This technique lacks the simulation of bearing stresses, stress concentration at the bolt hole location, and bending stiffness of the bolt. The second method, uses 3D models that provides the actual nut and bolt surfaces, bearing stresses are introduced in the joint modeling. Classical hand calculations are carried out on the static tests and compared with the FEM results. Additionally, the effects of element mesh refinement on the nut and bolt contact surfaces, and types of contacts are analyzed for the 3D models. A parametric study is carried out on the stresses developed and stress concentration factors.

Some Useful Tests for the Finite Element Meshes of Polycrystals With Explicit Account of the Grains and Grain Boundaries

2010 ◽  
Author(s):  
Igor Simonovski ◽  
Leon Cizelj
Keyword(s):  
Finite Element ◽  
Grain Boundaries ◽  
Element Model ◽  
Finite Element Mesh ◽  
Finite Element Models ◽  
Mesh Quality ◽  
Intergranular Cracking ◽  
Element Mesh ◽  
Random Lattice ◽  
Consistency Model

A growing number of computational material science and computational mechanics research is currently devoted to the explicit modeling of microstructures at various length and time scales. The finite element models of grains and grain boundaries in polycrystals include discretization of the grain interior. In addition, grain boundaries are explicitly discretized as cohesive zones with appropriate damage properties to facilitate the simulation of intergranular cracking. Such finite element models may easily involve hundreds of grains and millions of finite elements. They may also be combined with advanced lattice orientation dependent constitutive models, such as for example anisotropic elasticity and crystal plasticity. The complexity of the model, including the random lattice orientations, may therefore represent a serious difficulty in detecting possible issues in the finite element model and the interpretation of the results. A number of self-consistency model-checks are therefore needed to verify the model. Two tests are proposed and demonstrated in the paper. The first is aiming at the assessment of the finite element mesh quality within the grains in terms of the results. The second is primarily aiming at the verification of the consistent modeling of the cohesive layer at the grain boundaries. In addition, some useful information about the finite element mesh quality in terms of results is also given.

Finite Element Modeling of Rollover Crash Tests With Hybrid III Dummies

2007 ◽  
Author(s):  
Keith Friedman ◽  
John Hutchinson ◽  
Dennis Mihora
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
The United States ◽  
Finite Element Models ◽  
Element Modeling ◽  
Roof Structure ◽  
Hybrid Iii ◽  
The Impact ◽  
Rollover Crash ◽  
Crash Tests

This paper reports on the finite element modeling of rollover crash tests with Hybrid III dummies. Finite element models of a vehicle design and the Hybrid III dummy were used to evaluate the subsystem under manufacturer created rollover conditions for a production and roll caged roof structure. The objective of this study was to demonstrate the ability to reproduce the impact environment occurring in rollover crash tests. There are over 26,000 fatalities and serious injuries annually occurring in rollover accidents in the United States. Many of these are to restrained occupants and their head and spinal injuries have been associated with contact with the roof structure. To analyze the crash tests the effects of the system, finite element models were made of rollover crash tests that had been conducted using baseline and modified passenger vehicles and Hybrid III dummies using the defined impact conditions. Neck loads were utilized to validate the model against the test results. The results show that finite element modeling can reproduce the results from rollover crash tests.

Finite Element Modeling and Modal Analysis of Coilable Mast

2012 ◽  
Vol 226-228 ◽  
pp. 299-302
Author(s):  
Jie Wang ◽  
Dong Xu Li ◽  
Jian Ping Jiang
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Modal Analysis ◽  
Natural Frequencies ◽  
Space Mission ◽  
Joint Model ◽  
Finite Element Models ◽  
Attached Mass ◽  
Element Modeling ◽  
Tension Level

This paper investigates the modal characteristics of a coilable mast for space mission applications. Finite element models are established for characterizing the coilable mast. The simplification of joints between longerons and batten frames and the pre-tension in cables are carefully considered. A parametric modal analysis is performed with considering the following factors, the joint model in the truss, the pre-tension in cables, elements selected for longerons and battens, the mass attached to the top of the mast. Research results show that the natural frequencies of the coilable mast are sensitive to the selected elements and the attached mass. The pre-tension level in cables and the precision degree of the joint model have little effect on natural frequencies. The regularity expressed in the parametric modal analysis is useful for designers and engineers.

Automatic Finite Element Mesh Generation Over Domains Comprised of Military Connected, Intersecting, Rigid Body-Movable Subdomains

1989 ◽  
Author(s):  
H. Yang ◽  
D. A. Hoeltzel
Keyword(s):  
Finite Element ◽  
Rigid Body ◽  
Parametric Design ◽  
Body Movement ◽  
Automatic Generation ◽  
Finite Element Mesh ◽  
Acetabular Cup ◽  
Element Mesh ◽  
Multiply Connected ◽  
Novel Approach

Abstract A novel approach for the automatic generation and refinement of finite element meshes over nonconvex domains subdivided by multiply connected, rigid body-movable subdomains has been developed. The basis of this method relies on 1) the automatic insertion of nodes on the digitized boundaries and within the interiors of movable subdomains 2) the generation of superelement meshes, using the nodes which have been inserted on the subdomains, 3) determination of the points of intersection between adjacent subdomains following their rigid body movement, 3) ensuring the satisfaction of both interelement connectivity and compatability across subdomain boundaries which undergo rigid body movement along with the subdomains, and 4) the interactive refinement of userselectable subdomains using quadrilaterization for global refinement and triangularization for local refinement. The creation of a finite element mesh for an acetabular cup inserted in a human pelvis, which is representative of a mesh generated over complex, two-dimensional, multiply connected subdomains, as employed in an orthopedic total hip replacement, serves as a realistic application of this approach and demonstrates its utility for expeditiously performing finite element-based, parametric design optimization studies.

Automatic Finite Element Mesh Generation Over Domains Comprised of Multiply Connected, Intersecting, Rigid Body-Movable Subdomains

1992 ◽  
Vol 114 (4) ◽  
pp. 603-615 ◽  
Author(s):  
Hyunik Yang ◽  
D. A. Hoeltzel
Keyword(s):  
Finite Element ◽  
Rigid Body ◽  
Parametric Design ◽  
Body Movement ◽  
Automatic Generation ◽  
Finite Element Mesh ◽  
Acetabular Cup ◽  
Element Mesh ◽  
Multiply Connected ◽  
Nonconvex Domains

An approach for the automatic generation and refinement of finite element meshes over nonconvex domains subdivided by multibody connected, rigid body-movable subdomains has been developed. The basis of this method relies in order on (1) the automatic insertion of nodes on the digitized boundaries and within the interiors of movable subdomains, (2) the generation of superelement meshes within the subdomains, (3) determination of intersection points between adjacent subdomains following their rigid body movement, (4) ensuring the satisfaction of interelement connectivity across subdomain boundaries, and (5) the interactive refinement of user-selectable subdomains using quadrilaterization for global refinement and triangularization for local refinement. The creation of a finite element mesh for an acetabular cup inserted in a human pelvis, which is representative of a mesh generated over complex, two-dimensional, multiply connected subdomains, as employed in an orthopedic total hip replacement, serves as a realistic application of this approach and demonstrates its utility for expeditiously performing finite element-based, parametric design studies.

Forced Response of Disks due to Distributed Pressure Fields

2001 ◽  
Author(s):  
A. H. Mohamad ◽  
J. Ravoux ◽  
G. Jacquet-Richardet
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Analytical Model ◽  
Forced Response ◽  
Major Influence ◽  
Finite Element Models ◽  
Circular Plates ◽  
Element Modeling ◽  
Pressure Fields ◽  
Distributed Pressure

Abstract The shape and the frequency of excitation, induced by distributed pressure fields, have both a major influence on the associated response of bladed disks. The way those pressure fields are considered by finite element models have then to be as accurate as possible. In this paper, an analytical model, adapted to the prediction of the forced response of clamped-free circular plates, due to distributed pressure fields, is first derived. This model is considered as a reference in order to assess the effectiveness of different finite element modeling.

scholarly journals The problem of mathematical finite element modeling of inhomogeneous deformable solids using scanning

2019 ◽  
Vol 19 (3) ◽  
pp. 281-289
Author(s):  
V. L. Duong
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Strain State ◽  
Mechanical Characteristics ◽  
Finite Element Models ◽  
Mathematical Methods ◽  
Stress Strain ◽  
Computer Tomograph ◽  
Element Modeling ◽  
Deformable Solids

Introduction. In the mathematical finite element modeling, an average value of the mechanical characteristics of the deformable solid material is used. In aircraft, machine building, construction engineering, medicine and other fields, polymer composite materials and materials of natural origin are increasingly used. In the latter case, the actual change in the mechanical characteristics differs significantly from the averaged change; therefore, when using the averaged parameters to build and analyze finite element models, the results can be significantly distorted. This paper describes the creation of mathematical methods for studying changes in the mechanical characteristics of a material of inhomogeneous deformable solids. The results obtained in this way are used to construct finite element models and analyze their stress-strain state.Materials and Methods. Naturally occurring materials and composites are considered as inhomogeneous deformable solids. To study the changes in the mechanical characteristics of the material, a method was developed based on the use of two components: the pixel characteristics of raster images scanned by a computer tomograph and the experimental data of field tests of standard samples.Research Results. A complex of mathematical methods has been developed for modeling the interpretation of scanning raster images by a computer tomograph, which allows for the study of any complicated structures of real deformable solids. The results are used in the construction of finite element models of such bodies considering the heterogeneity of the mechanical characteristics of the material. The analysis of the stress-strain state of finite element models of test samples has proved the accuracy and convergence of the numerical solution of the finite element method in modeling the property of heterogeneity of the mechanical characteristics of the material.Discussion and Conclusions. The developed approach can be applied to any physical principles of scanning (X-ray, ultrasound, laser, etc.) and for any types of materials if the data obtained as a result of scanning is developed in the form of a digital (raster) image.

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