
196fe00e701d3ed46d13917ec4365d10.ppt
- Количество слайдов: 74
23. 3. 2006 ISCM-20 Pinhas Z. Bar-Yoseph Computational Mechanics Lab. Mechanical Engineering, Technion Copyright by PZ Bar-Yoseph ©
Bar-Yoseph, Appl. Num. Math. 33, 435 -445, 2000
Aharoni & Bar-Yoseph, Comp. Mech. 9, 359 -374, 1992 DSM for Dynamic systems
Discontinuous element
Nonlinear Spatio-Temporal Dynamics of a Flexible Rod Plat & Bar-Yoseph, 27 th Israel Conf. Mech. Eng. 683 -685, 1998
Bar-Yoseph, Appl. Num. Math. 33, 435 -445, 2000
Nave, Bar-Yoseph & Halevi, Dynamics. & Control. 9, 279 -296, 1999 The unicycle system, presents an example of inherently unstable system which can be autonomously controlled and stabilized by a skilled rider -required to maintain the unicylce’s upright position -required to maintain lateral stability -the friction torque is assumed to be dependent on the yew rate only
The adaptive technique performed very well for all stiff systems that we have experienced with (convection, radiation and chemical reactions), and is competitive with the best Gear-type routines
Space-Time Discontinuous Approximations
Bar-Yoseph & Elata, IJNME, 29, 1229 -1245, 1990
Bar-Yoseph & Elata & Israeli, IJNME, 36, 679 -694, 1993; Golzman & Bar-Yoseph (Project)
Bar-Yoseph & Elata & Israeli, IJNME, 36, 679 -694, 1993; Golzman & Bar-Yoseph (Project)
Bar-Yoseph & Elata, IJNME, 29, 1229 -1245, 1990
Fischer & Bar-Yoseph, IJNME, 48, 1571 -1582, 2000
Advanced CAD Visualization Methods Adaptive Level of Details Technique for Meshing
Morphing between Meshes at Different Times
CGM Conforming elements. DGM Elements are discontinuous.
Space-Time Discontinuous Approximations
Discontinuous SPECTRAL ELEMENTS • Gauss-Lobatto nodes are clustered near element boundaries and are chosen because of their interpolation and quadrature properties. • Mass lumping by nodal quadrature. • Exponential rate of convergence. • The increase in the due to the discontinuity at the interelement boundaries is balanced in high order elements.
Flux Splitting Bar-Yoseph, Comput. Mech. , 5, 145 -160, 1989
Miles Rubin (2005) Nonlinear Wave Eq.
Flux splitting for non homogeneous
Traper & Bar-Yoseph (Project) where: The effective wave speed: In a matrix form:
• The Jacobian matrix: • The eigenvalues: • The corresponding eigenvectors:
Traper & Bar-Yoseph (Project) Displacement
Velocity
Strain
• -Time for breakdown [Lax (1964)]:
bilinear biquadratic Velocity at t = 3 sec x
bilinear biquadratic Strain at t = 3 sec x
Bar-Yoseph et al. , JCP, 119, 62 -74, 1995
Bar-Yoseph & Moses, IJNMHFF, 7, 215 -235, 1997
Cockburn& Shu, JCP, 84, 90, 1989; Basi & Rebay, JCP, 131, 267 -279, 1997
196fe00e701d3ed46d13917ec4365d10.ppt