Objectivity of strain measures in the geometrically exact three-dimensional beam theory and its finite-element implementation

1999 ◽  
Vol 455 (1983) ◽  
pp. 1125-1147 ◽  
Author(s):  
Michael A. Crisfield ◽  
Gordan Jelenić;
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Beam Theory ◽  
Finite Element Implementation ◽  
Strain Measures

A finite element model to study the effect of porosity location on the elastic modulus of a cantilever beam

2019 ◽  
Vol 43 (4) ◽  
pp. 443-453
Author(s):  
Stephen M. Handrigan ◽  
Sam Nakhla
Keyword(s):  
Finite Element ◽  
Elastic Modulus ◽  
Focused Ion Beam ◽  
Mechanical Response ◽  
Ion Beam ◽  
Three Dimensional ◽  
Beam Theory ◽  
Element Model ◽  
Fe Model ◽  
Three Dimensional Finite Element

An investigation to determine the effect of porosity concentration and location on elastic modulus is performed. Due to advancements in testing methods, the manufacturing and testing of microbeams to obtain mechanical response is possible through the use of focused ion beam technology. Meanwhile, rigorous analysis is required to enable accurate extraction of the elastic modulus from test data. First, a one-dimensional investigation with beam theory, Euler–Bernoulli and Timoshenko, was performed to estimate the modulus based on load-deflection curve. Second, a three-dimensional finite element (FE) model in Abaqus was developed to identify the effect of porosity concentration. Furthermore, the current work provided an accurate procedure to enable accurate extraction of the elastic modulus from load-deflection data. The use of macromodels such as beam theory and three-dimensional FE model enabled enhanced understanding of the effect of porosity on modulus.

Three-Dimensional Finite Element Analysis of a Simplified Compression Plate Fixation System

1984 ◽  
Vol 106 (4) ◽  
pp. 295-301 ◽  
Author(s):  
E. J. Cheal ◽  
W. C. Hayes ◽  
A. A. White ◽  
S. M. Perren
Keyword(s):  
Finite Element ◽  
Strain Gage ◽  
Composite Beam ◽  
Plate Fixation ◽  
Three Dimensional ◽  
Beam Theory ◽  
Fracture Site ◽  
Test Model ◽  
Element Analysis ◽  
Compression Plate

A three-dimensional, linear finite element model was generated for an intact plexiglass tube with an attached six-hole stainless steel compression plate. We examined external forces representing axial, off-center axial, and four-point bending, along with superimposed plate and screw pretension. Strain gage experiments were conducted to test model validity and the finite element results were contrasted to a composite beam theory solution. Excellent correspondence was observed between finite element and strain gage data for the most significant strain components. Composite beam theory tended to overestimate the neutral axis shift which results from plate application. The model also demonstrated fracture site distraction due to plate pretension, and the tendency for outer screw failure for the combination of bending-closed with a preload in the plate and screws.

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