scholarly journals Parametric Study of Effects of Brain-Skull Boundary Conditions and Brain Material Properties on Responses of Simplified Finite Element Brain Model under Angular Acceleration Impulse in Sagittal Plane

2003 ◽  
Vol 46 (4) ◽  
pp. 1388-1399 ◽  
Author(s):  
Adam WITTEK ◽  
Kiyoshi OMORI
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
Material Properties ◽  
Parametric Study ◽  
Sagittal Plane ◽  
Angular Acceleration ◽  
Brain Material

Numerical Study of the Effect of Geometry and Boundary Conditions on the Collapse Behaviour of Stocky Stiffened Panels

2012 ◽  
Vol 154 (A2) ◽  
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
Ultimate Strength ◽  
Material Properties ◽  
Finite Element Modelling ◽  
Numerical Study ◽  
Fe Analysis ◽  
Stiffened Panels ◽  
Element Modelling ◽  
Geometric Configurations

This study aims at studying different configurations of the stiffened panels in order to identify robust configurations that would not be much sensitive to the imprecision in boundary conditions that can exist in experimental set ups. A numerical study is conducted to analyze the influence of the stiffener’s geometry and boundary conditions on the ultimate strength of stiffened panels under uniaxial compression. The stiffened panels with different combinations of mechanical material properties and geometric configurations are considered. The four types of stiffened panels analysed are made of mild or high tensile steel and have bar, ‘L’ and ‘U’ stiffeners. To understand the effect of finite element modelling on the ultimate strength of the stiffened panels, four types of FE models are investigated in FE analysis including 3 bays, 1/2+1+1/2 bays, 1+1 bays and 1 bay with different boundary conditions.

Vibro-Acoustic Studies of Transmission Casing Structures

1998 ◽  
Author(s):  
D. Crimaldi ◽  
R. Singh
Keyword(s):  
Finite Element ◽  
Free Boundary ◽  
Boundary Conditions ◽  
Material Properties ◽  
Acoustic Radiation ◽  
Real Life ◽  
Cover Plate ◽  
Mode Shapes ◽  
Finite Element Models ◽  
Free Boundary Conditions

Abstract Automotive transmission casing plates of irregular shape, with complex boundary conditions and non-uniform material properties, are experimentally and computationally studied to acquire a fundamental understanding of their dynamic and acoustic radiation characteristics. A modified flat cover is designed which simplifies the geometry while providing uniform thickness and material properties. Both covers (“real-life” and “laboratory”) are studied with free and bolted boundary conditions. In particular, the free boundary conditions are useful because they eliminate the cover-housing interaction allowing for a more detailed analysis of the cover plate. Finite element models for both covers under the free boundary conditions are developed and refined. Predicted natural frequencies and mode shapes are in excellent agreement with measured modal data. Then the finite element models are coupled with boundary element models to predict acoustic radiation properties. Predictions match well with measured acoustic directivity at resonant frequencies.

scholarly journals Comparison of Experimentally Measured Deformation of the Plate on the Subsoil and the Results of 3D Numerical Model

2014 ◽  
Vol 14 (1) ◽  
pp. 57-66 ◽  
Author(s):  
Jana Labudková ◽  
Radim Čajka
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Boundary Conditions ◽  
Parametric Study ◽  
3D Model ◽  
3D Elements ◽  
Final Deformation ◽  
Measured Deformation ◽  
3D Numerical Model

Abstract The purpose of this paper is to compare the measured subsidence of the foundation in experiments and subsidence obtained from FEM calculations. When using 3D elements for creation of a 3D model, it is, in particular, essential to choose correctly the size of the modelled area which represents the subsoil, the boundary conditions and the size of the finite element network. The parametric study evaluates impacts of those parameters on final deformation. The parametric study is conducted of 168 variant models.

NUMERICAL STUDY OF THE EFFECT OF GEOMETRY AND BOUNDARY CONDITIONS ON THE COLLAPSE BEHAVIOUR OF STOCKY STIFFENED PANELS

2021 ◽  
Vol 154 (A2) ◽  
Author(s):  
M C Xu ◽  
C Guedes Soares
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
Ultimate Strength ◽  
Material Properties ◽  
Finite Element Modelling ◽  
Numerical Study ◽  
Fe Analysis ◽  
Stiffened Panels ◽  
Element Modelling ◽  
Geometric Configurations

This study aims at studying different configurations of the stiffened panels in order to identify robust configurations that would not be much sensitive to the imprecision in boundary conditions that can exist in experimental set ups. A numerical study is conducted to analyze the influence of the stiffener’s geometry and boundary conditions on the ultimate strength of stiffened panels under uniaxial compression. The stiffened panels with different combinations of mechanical material properties and geometric configurations are considered. The four types of stiffened panels analysed are made of mild or high tensile steel and have bar, ‘L’ and ‘U’ stiffeners. To understand the effect of finite element modelling on the ultimate strength of the stiffened panels, four types of FE models are investigated in FE analysis including 3 bays, 1/2+1+1/2 bays, 1+1 bays and 1 bay with different boundary conditions.

Development of an Advanced Finite Element Model and Parametric Study to Evaluate Cement Sheath Barrier

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Harshkumar Patel ◽  
Saeed Salehi
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Material Properties ◽  
Parametric Study ◽  
Element Model ◽  
Mechanical Stresses ◽  
Response Curves ◽  
Cement Material ◽  
Wellbore Pressure ◽  
Cement Sheath

Cement failure is known as one of the major causes for loss of well control events. Cement design is considered as one of the top technological knowledge gaps in high-pressure high-temperature oil and gas exploration. The primary objective of this paper is to perform a parametric analysis and identify critical parameters affecting the mechanical integrity of the set cement sheath. To achieve the objective, three-dimensional finite element models consisting of concentric casings and annular cement sheath were created. The finite element model was validated by analytical calculations. Performance of cement sheath was assessed by analyzing radial, hoop, and maximum shear stresses at different loading conditions. A parametric study was conducted by individually varying influencing factors such as cement material properties, sheath dimensions, and wellbore pressure loads. Values of all parameters were normalized and represented on the same plot against mechanical stresses. Such response curves can be used to estimate whether cement will structurally fail because of various operational loads or material aging. The plot can also be utilized to rank various factors in terms of influence on cement’s performance. Sensitivity response reveals that wellbore pressure, cement material properties, and annulus pressure are major parameters influencing mechanical stresses in neat class G cement. The order of importance depends on the type of stress. Results indicate interfacial bond failure and radial cracking to be the more likely modes of failure for class G cement. Cement response curves can help design engineers and regulators alike in quickly evaluating short-term or long-term fitness-for-service of cement sheath from the perspective of structural integrity. Industry standards and guidelines can be improved by adding performance curves for standard cement recipes.

A REVIEW OF FINITE ELEMENT APPLICATIONS IN ORAL AND MAXILLOFACIAL BIOMECHANICS

2018 ◽  
Vol 18 (02) ◽  
pp. 1830002 ◽  
Author(s):  
SUZAN CANSEL DOGRU ◽  
EROL CANSIZ ◽  
YUNUS ZIYA ARSLAN
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
Material Properties ◽  
Dental Materials ◽  
Numerical Approach ◽  
Patient Specific ◽  
Element Analysis ◽  
Biomechanical Models ◽  
Dental Instruments ◽  
Wide Range

Finite element method (FEM) is preferred to carry out mechanical analyses for many complex biomechanical structures. For most of the biomechanical models such as oral and maxillofacial structures or patient-specific dental instruments, including nonlinearities, complicated geometries, complex material properties, or loading/boundary conditions, it is not possible to accomplish an analytical solution. The FEM is the most widely used numerical approach for such cases and found a wide range of application fields for investigating the biomechanical characteristics of oral and maxillofacial structures that are exposed to external forces or torques. The numerical results such as stress or strain distributions obtained from finite element analysis (FEA) enable dental researchers to evaluate the bone tissues subjected to the implant or prosthesis fixation from the viewpoint of (i) mechanical strength, (ii) material properties, (iii) geometry and dimensions, (iv) structural properties, (v) loading or boundary conditions, and (vi) quantity of implants or prostheses. This review paper evaluates the process of the FEA of the oral and maxillofacial structures step by step as followings: (i) a general perspective on the techniques for creating oral and maxillofacial models, (ii) definitions of material properties assigned to oral and maxillofacial tissues and related dental materials, (iii) definitions of contact types between tissue and dental instruments, (iv) details on loading and boundary conditions, and (v) meshing process.

Assessment of Factors Influencing Finite Element Vertebral Model Predictions

2007 ◽  
Vol 129 (6) ◽  
pp. 898-903 ◽  
Author(s):  
Alison C. Jones ◽  
Ruth K. Wilcox
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
Material Property ◽  
Material Properties ◽  
Property Values ◽  
Sensitivity Study ◽  
Element Analysis ◽  
Homogeneous Models ◽  
Specific Material ◽  
Similar Accuracy

This study aimed to establish model construction and configuration procedures for future vertebral finite element analysis by studying convergence, sensitivity, and accuracy behaviors of semiautomatically generated models and comparing the results with manually generated models. During a previous study, six porcine vertebral bodies were imaged using a microcomputed tomography scanner and tested in axial compression to establish their stiffness and failure strength. Finite element models were built using a manual meshing method. In this study, the experimental agreement of those models was compared with that of semiautomatically generated models of the same six vertebrae. Both manually and semiautomatically generated models were assigned gray-scale-based, element-specific material properties. The convergence of the semiautomatically generated models was analyzed for the complete models along with material property and architecture control cases. A sensitivity study was also undertaken to test the reaction of the models to changes in material property values, architecture, and boundary conditions. In control cases, the element-specific material properties reduce the convergence of the models in comparison to homogeneous models. However, the full vertebral models showed strong convergence characteristics. The sensitivity study revealed a significant reaction to changes in architecture, boundary conditions, and load position, while the sensitivity to changes in material property values was proportional. The semiautomatically generated models produced stiffness and strength predictions of similar accuracy to the manually generated models with much shorter image segmentation and meshing times. Semiautomatic methods can provide a more rapid alternative to manual mesh generation techniques and produce vertebral models of similar accuracy. The representation of the boundary conditions, load position, and surrounding environment is crucial to the accurate prediction of the vertebral response. At present, an element size of 2×2×2mm3 appears sufficient since the error at this size is dominated by factors, such as the load position, which will not be improved by increasing the mesh resolution. Higher resolution meshes may be appropriate in the future as models are made more sophisticated and computational processing time is reduced.

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