The impact of boundary conditions and mesh size on the accuracy of cancellous bone tissue modulus determination using large-scale finite-element modeling

1999 ◽  
Vol 32 (11) ◽  
pp. 1159-1164 ◽  
Author(s):  
C.R Jacobs ◽  
B.R Davis ◽  
C.J Rieger ◽  
J.J Francis ◽  
M Saad ◽  
...  
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
Finite Element Modeling ◽  
Bone Tissue ◽  
Cancellous Bone ◽  
Large Scale ◽  
Mesh Size ◽  
Element Modeling ◽  
Tissue Modulus ◽  
The Impact

Experimentally validated predictive finite element modeling of the V0-V100 probabilistic penetration response of a Kevlar fabric against a spherical projectile

2018 ◽  
Vol 9 (4) ◽  
pp. 504-524 ◽  
Author(s):  
Gaurav Nilakantan
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Finite Element Modeling ◽  
Element Model ◽  
Ballistic Impact ◽  
Impact Testing ◽  
Woven Fabric ◽  
Projectile Impact ◽  
Element Modeling ◽  
The Impact

This work presents the first fully validated and predictive finite element modeling framework to generate the probabilistic penetration response of an aramid woven fabric subjected to ballistic impact. This response is defined by a V0-V100 curve that describes the probability of complete fabric penetration as a function of projectile impact velocity. The exemplar case considered in this article comprises a single-layer, fully clamped, plain-weave Kevlar fabric impacted at the center by a 0.22 cal spherical steel projectile. The fabric finite element model comprises individually modeled three-dimensional warp and fill yarns and is validated against the experimental material microstructure. Sources of statistical variability including yarn strength and modulus, inter-yarn friction, and precise projectile impact location are mapped into the finite element model. A series of impact simulations at varying projectile impact velocities is executed using LS-DYNA on the fabric models, each comprising unique mappings. The impact velocities and outcomes (penetration, non-penetration) are used to generate the numerical V0-V100 curve which is then validated against the experimental V0-V100 curve obtained from ballistic impact testing and shown to be in excellent agreement. The experimental data and its statistical analysis used for model input and validation, namely, the Kevlar yarn tensile strengths and moduli, inter-yarn friction, and fabric ballistic impact testing, are also reported.

scholarly journals Characterization of Maple and Ash Material Properties for the Finite Element Modeling of Wood Baseball Bats

2018 ◽  
Vol 8 (11) ◽  
pp. 2256 ◽  
Author(s):  
Joshua Fortin-Smith ◽  
James Sherwood ◽  
Patrick Drane ◽  
David Kretschmann
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Material Properties ◽  
Charpy Impact ◽  
Impact Testing ◽  
Charpy Test ◽  
Ball Impact ◽  
Element Modeling ◽  
The Impact ◽  
Baseball Bats

To assist in developing a database of wood material properties for the finite element modeling of wood baseball bats, Charpy impact testing at strain rates comparable to those that a wood bat experiences during a bat/ball collision is completed to characterize the failure energy and strain-to-failure as a function of density and slope-of-grain (SoG) for northern white ash (Fraxinus americana) and sugar maple (Acer saccharum). Un-notched Charpy test specimens made from billets of ash and maple that span the range of densities and SoGs that are approved for making professional baseball bats are impacted on either the edge grain or face grain. High-speed video is used to capture each test event and image analysis techniques are used to determine the strain-to-failure for each test. Strain-to-failure as a function of density relations are derived and these relations are used to calculate inputs to the *MAT_WOOD (Material Model 143) and *MAT_EROSION material options in LS-DYNA for the subsequent finite element modeling of the ash and maple Charpy Impact tests and for a maple bat/ball impact. The Charpy test data show that the strain-to-failure increases with increasing density for maple but the strain-to-failure remains essentially constant over the range of densities considered in this study for ash. The flat response of the ash data suggests that ash-bat durability is less sensitive to wood density than maple-bat durability. The available SoG results suggest that density has a greater effect on the impact failure properties of the wood than SoG. However, once the wood begins to fracture, SoG plays a large role in the direction of crack propagation of the wood, thereby determining if the shape of the pieces breaking away from the bat are fairly blunt or spear-like. The finite element modeling results for the Charpy and bat/ball impacts show good correlation with the experimental data.

Finite Element Modeling of Electrostatic MEMS Including the Impact of Fringing Field Effects on Forces

2008 ◽  
Vol 6 (1) ◽  
pp. 115-120 ◽  
Author(s):  
Mohamed Boutaayamou ◽  
Ruth V. Sabariego ◽  
Patrick Dular
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Element Modeling ◽  
Field Effects ◽  
Electrostatic Mems ◽  
Fringing Field ◽  
The Impact

Proposed damage evolution model for large-scale finite element modeling of the dual coolant US-ITER TBM

2007 ◽  
Vol 367-370 ◽  
pp. 1337-1343 ◽  
Author(s):  
S. Sharafat ◽  
J. El-Awady ◽  
S. Liu ◽  
E. Diegele ◽  
N.M. Ghoniem
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Damage Evolution ◽  
Large Scale ◽  
Evolution Model ◽  
Element Modeling
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