scholarly journals A Finite Element Study of Electromagnetic Riveting

1999 ◽  
Vol 121 (1) ◽  
pp. 61-68 ◽  
Author(s):  
E. A. Repetto ◽  
R. Radovitzky ◽  
M. Ortiz ◽  
R. C. Lundquist ◽  
D. R. Sandstrom
Keyword(s):  
Finite Element ◽  
Material Properties ◽  
Aerospace Industry ◽  
Stress And Strain ◽  
Structural Elements ◽  
Aerospace Assembly ◽  
Structure Configuration ◽  
Rapid Plastic Deformation ◽  
Rapid Deformation ◽  
Electromagnetic Riveting

Electromagnetic riveting, used in some aerospace assembly processes, involves rapid deformation, leading to the finished rivet configuration. Analysis of this process is described for the case of an aluminum rivet joining typical aluminum structural elements. The analysis is based on a finite element method that includes the effects of heating, due to rapid plastic deformation of the material, on the material properties. Useful details of material deformation and thermal history and the final rivet and structure configuration and states of stress and strain are obtained. These results have significant implications in the design, implementation, and improvement of practical fastening processes in the aerospace industry.

Application of a Density-Elastic Modulus Equation Developed for the Distal Ulna to Multiple Forearm Positions: A Finite Element Study

2011 ◽  
Author(s):  
Mark A. C. Neuert ◽  
Rebecca L. Austman ◽  
Cynthia E. Dunning
Keyword(s):  
Finite Element ◽  
Elastic Modulus ◽  
Material Properties ◽  
Experimental Studies ◽  
Strain Gauges ◽  
Stress And Strain ◽  
Distal Ulna ◽  
Strain Measurements ◽  
Multiple Loading ◽  
Element Study

Compared to experimental studies using strain gauges, finite element (FE) models are not limited to strain measurements at discrete locations and can be used to examine the continuous strain and stress field throughout bone. As such, they can be a useful tool for biomechanical investigations interested in stress and strain changes as a result of multiple loading conditions, implant designs, etc. Critical to their development is the assignment of material properties.

scholarly journals Finite element analysis relating shape, material properties, and dimensions of taenioglossan radular teeth with trophic specialisations in Paludomidae (Gastropoda)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wencke Krings ◽  
Jordi Marcé-Nogué ◽  
Stanislav N. Gorb
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Material Properties ◽  
Stress And Strain ◽  
Plant Surface ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Force Volume ◽  
General Size

AbstractThe radula, a chitinous membrane with embedded tooth rows, is the molluscan autapomorphy for feeding. The morphologies, arrangements and mechanical properties of teeth can vary between taxa, which is usually interpreted as adaptation to food. In previous studies, we proposed about trophic and other functional specialisations in taenioglossan radulae from species of African paludomid gastropods. These were based on the analysis of shape, material properties, force-resistance, and the mechanical behaviour of teeth, when interacting with an obstacle. The latter was previously simulated for one species (Spekia zonata) by the finite-element-analysis (FEA) and, for more species, observed in experiments. In the here presented work we test the previous hypotheses by applying the FEA on 3D modelled radulae, with incorporated material properties, from three additional paludomid species. These species forage either on algae attached to rocks (Lavigeria grandis), covering sand (Cleopatra johnstoni), or attached to plant surface and covering sand (Bridouxia grandidieriana). Since the analysed radulae vary greatly in their general size (e.g. width) and size of teeth between species, we additionally aimed at relating the simulated stress and strain distributions with the tooth sizes by altering the force/volume. For this purpose, we also included S. zonata again in the present study. Our FEA results show that smaller radulae are more affected by stress and strain than larger ones, when each tooth is loaded with the same force. However, the results are not fully in congruence with results from the previous breaking stress experiments, indicating that besides the parameter size, more mechanisms leading to reduced stress/strain must be present in radulae.

scholarly journals Finite Element Analysis Relating Shape, Material Properties, and Dimensions of Taenioglossan Radular Teeth with Trophic Specialisations in Paludomidae (Gastropoda)

2021 ◽  
Author(s):  
Wencke Krings ◽  
Jordi Marcé-Nogué ◽  
Stanislav N. Gorb
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Mechanical Behaviour ◽  
Material Properties ◽  
Stress And Strain ◽  
Plant Surface ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Force Volume

Abstract The radula, a chitinous membrane with embedded tooth rows, is the molluscan autapomorphy for feeding. The morphologies, arrangements and mechanical properties of teeth can vary between taxa, which is usually interpreted as adaptation to food. In previous studies, we proposed about trophic and other functional specialisations in taenioglossan radulae from species of African paludomid gastropods. These were based on the analysis of shape, material properties, force-resistance, and the mechanical behaviour of teeth, when interacting with an obstacle, which was previously simulated for one species (Spekia) by the finite-element-analysis (FEA) and, for more species, observed in experiments. In the here presented work, we test the previous hypotheses by applying the FEA on 3D modelled radulae, with incorporated material properties, from three additional paludomid species. These species forage either on algae attached to rocks (Lavigeria), covering sand (Cleopatra), or attached to plant surface and covering sand (Bridouxia). Since the analysed radulae vary greatly in their size between species, we additionally aimed at relating the simulated stress and strain distributions with the tooth sizes by altering the force/volume. For this purpose, we also included Spekia again in the present study. Our FEA results show that smaller radulae are more affected by stress and strain than larger ones, when each tooth is loaded with the same force. However, the results are not fully in congruence with results from the previous breaking stress experiments, indicating that besides the parameter size, more mechanisms leading to reduced stress/strain must be present in radulae.

3d Reconstruction and Nonlinear Finite Element Analysis of the Embryonic Left Ventricle

2007 ◽  
Author(s):  
Daniela Faas ◽  
Christine Buffinton ◽  
David Sedmera
Keyword(s):  
Finite Element ◽  
Left Ventricle ◽  
3D Reconstruction ◽  
Material Properties ◽  
Pressure Overload ◽  
Passive State ◽  
Stress And Strain ◽  
Element Analysis ◽  
Developing Heart ◽  
Element Technique

Changes in mechanical loading in the developing heart produce changes in morphology and mechanical material properties [1–3]. Understanding the relationship of these changes to mechanical stress and strain in the left ventricle requires a geometrically accurate model of the entire ventricle including the trabecular pattern and material property, boundary condition, and loading specification. A 3D reconstruction and finite element technique were developed to reconstruct the heart from serial confocal sections and calculate stress and strain distributions over the volume for the passive state. Control hearts and two treatments, pressure overload and pressure underload, were modeled. The results show that stresses in the trabeculae are much larger than those in the ventricular walls. Strains in the pressure-overloaded hearts were significantly smaller than in control or underloaded, indicating the stiffer material properties more than compensate for the increased internal pressure.

Voxel-based finite element modelling of wood elements based on spatial density and geometry data using computed tomography

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jens U. Hartig ◽  
André Bieberle ◽  
Chris Engmann ◽  
Peer Haller
Keyword(s):  
Finite Element ◽  
Material Properties ◽  
Strain Distribution ◽  
Finite Element Modelling ◽  
Element Model ◽  
Spatial Density ◽  
Stress And Strain ◽  
Element Modelling ◽  
Stress And Strain Distribution ◽  
The Finite Element Model

Abstract In this paper, voxel-based finite element modelling based on spatial geometry and density data is applied to simulate the detailed stress and strain distribution in a large wood element. As example, a moulded wooden tube with a length of 3 m and a diameter of 0.3 m is examined. Gamma-ray computed tomography is used to obtain both, its actual geometric shape and spatial density distribution. Correlation functions (R2 ≈ 0.6) between density and elastic material properties are experimentally determined and serve as link for defining the non-uniform distribution of the material properties in the finite element model. Considering the geometric imperfections and spatial variation of the material properties, a detailed analysis of the stress and strain distribution of a wood element is performed. Additionally, a non-destructive axial compression test is applied on the wooden tube to analyse the load-bearing behaviour. By means of digital image correlation, the deformation of the surface is obtained, which also serves for validation of the finite element model in terms of strain distributions.

Determination of Charge Coefficient of Piezoelectric Films Using a Combined Finite Element Model and Dynamic Loading Technique

2020 ◽  
Vol 835 ◽  
pp. 229-242
Author(s):  
Oboso P. Bernard ◽  
Nagih M. Shaalan ◽  
Mohab Hossam ◽  
Mohsen A. Hassan
Keyword(s):  
Finite Element ◽  
Dynamic Loading ◽  
Material Properties ◽  
Accurate Determination ◽  
Substrate Material ◽  
Experimental Results ◽  
Piezoelectric Composite ◽  
Piezoelectric Film ◽  
Piezoelectric Charge

Accurate determination of piezoelectric properties such as piezoelectric charge coefficients (d33) is an essential step in the design process of sensors and actuators using piezoelectric effect. In this study, a cost-effective and accurate method based on dynamic loading technique was proposed to determine the piezoelectric charge coefficient d33. Finite element analysis (FEA) model was developed in order to estimate d33 and validate the obtained values with experimental results. The experiment was conducted on a piezoelectric disc with a known d33 value. The effect of measuring boundary conditions, substrate material properties and specimen geometry on measured d33 value were conducted. The experimental results reveal that the determined d33 coefficient by this technique is accurate as it falls within the manufactures tolerance specifications of PZT-5A piezoelectric film d33. Further, obtained simulation results on fibre reinforced and particle reinforced piezoelectric composite were found to be similar to those that have been obtained using more advanced techniques. FE-results showed that the measured d33 coefficients depend on measuring boundary condition, piezoelectric film thickness, and substrate material properties. This method was proved to be suitable for determination of d33 coefficient effectively for piezoelectric samples of any arbitrary geometry without compromising on the accuracy of measured d33.

scholarly journals Evaluation of Bone–Implant Interface Stress and Strain Using Heterogeneous Mandibular Bone Properties Based on Different Empirical Correlations

2021 ◽  
Author(s):  
Mostafa Omran Hussein ◽  
Mohammed Suliman Alruthea
Keyword(s):  
Finite Element ◽  
Group Iv ◽  
Von Mises Stress ◽  
Patient Specific ◽  
Dental Arch ◽  
Stress And Strain ◽  
Bone Implant ◽  
Bone Properties ◽  
Group I ◽  
Von Mises

Abstract Objective The purpose of this study was to compare methods used for calculating heterogeneous patient-specific bone properties used in finite element analysis (FEA), in the field of implant dentistry, with the method based on homogenous bone properties. Materials and Methods In this study, three-dimensional (3D) computed tomography data of an edentulous patient were processed to create a finite element model, and five identical 3D implant models were created and distributed throughout the dental arch. Based on the calculation methods used for bone material assignment, four groups—groups I to IV—were defined. Groups I to III relied on heterogeneous bone property assignment based on different equations, whereas group IV relied on homogenous bone properties. Finally, 150 N vertical and 60-degree-inclined forces were applied at the top of the implant abutments to calculate the von Mises stress and strain. Results Groups I and II presented the highest stress and strain values, respectively. Based on the implant location, differences were observed between the stress values of group I, II, and III compared with group IV; however, no clear order was noted. Accordingly, variable von Mises stress and strain reactions at the bone–implant interface were observed among the heterogeneous bone property groups when compared with the homogenous property group results at the same implant positions. Conclusion Although the use of heterogeneous bone properties as material assignments in FEA studies seem promising for patient-specific analysis, the variations between their results raise doubts about their reliability. The results were influenced by implants’ locations leading to misleading clinical simulations.

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