Finite element modeling of cerebral angioplasty using a structural multi-mechanism anisotropic damage model

2012 ◽  
Vol 92 (5) ◽  
pp. 457-474 ◽  
Author(s):  
Dalong Li ◽  
Anne M. Robertson ◽  
Guoyu Lin ◽  
Michael Lovell
Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1286
Author(s):  
Masud Alam ◽  
Liang Zhao ◽  
Napat Vajragupta ◽  
Junjie Zhang ◽  
Alexander Hartmaier

Machining of brittle ceramics is a challenging task because the requirements on the cutting tools are extremely high and the quality of the machined surface strongly depends on the chosen process parameters. Typically, the efficiency of a machining process increases with the depth of cut or the feed rate of the tool. However, for brittle ceramics, this easily results in very rough surfaces or even in crack formation. The transition from a smooth surface obtained for small depths of cut to a rough surface for larger depths of cut is called a brittle-to-ductile transition in machining. In this work, we investigate the mechanisms of this brittle-to-ductile transition for diamond cutting of an intrinsically brittle 3C-SiC ceramic with finite element modeling. The Drucker–Prager model has been used to describe plastic deformation of the material and the material parameters have been determined by an inverse method to match the deformation behavior of the material under nanoindentation, which is a similar loading state as the one occurring during cutting. Furthermore, a damage model has been introduced to describe material separation during the machining process and also crack initiation in subsurface regions. With this model, grooving simulations of 3C-SiC with a diamond tool have been performed and the deformation and damage mechanisms have been analyzed. Our results reveal a distinct transition between ductile and brittle cutting modes as a function of the depth of cut. The critical depth of cut for this transition is found to be independent of rake angle; however, the surface roughness strongly depends on the rake angle of the tool.


1991 ◽  
Vol 3 (1) ◽  
pp. 235-253 ◽  
Author(s):  
L. D. Philipp ◽  
Q. H. Nguyen ◽  
D. D. Derkacht ◽  
D. J. Lynch ◽  
A. Mahmood

1993 ◽  
Vol 21 (1) ◽  
pp. 23-39 ◽  
Author(s):  
R. W. Scavuzzo ◽  
T. R. Richards ◽  
L. T. Charek

Abstract Tire vibration modes are known to play a key role in vehicle ride, for applications ranging from passenger cars to earthmover equipment. Inputs to the tire such as discrete impacts (harshness), rough road surfaces, tire nonuniformities, and tread patterns can potentially excite tire vibration modes. Many parameters affect the frequency of tire vibration modes: tire size, tire construction, inflation pressure, and operating conditions such as speed, load, and temperature. This paper discusses the influence of these parameters on tire vibration modes and describes how these tire modes influence vehicle ride quality. Results from both finite element modeling and modal testing are discussed.


1987 ◽  
Vol 15 (1) ◽  
pp. 30-41 ◽  
Author(s):  
E. G. Markow

Abstract Development of the banded radial tire is discussed. A major contribution of this tire design is a reliable run-flat capability over distances exceeding 160 km (100 mi). Experimental tire designs and materials are considered; a brief theoretical discussion of the mechanics of operation is given based on initial two-dimensional studies and later on more complete finite element modeling. Results of laboratory tests for cornering, rolling resistance, and braking are presented. Low rolling resistance, good cornering and braking properties, and low tread wear rate along with good puncture resistance are among the advantages of the banded radial tire designs.


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