living matter lab
(Difference between revisions)
(teaching in general)
(project related reading)
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[http://biomechanics.stanford.edu/me337/projects/gene_regulation01.pdf  p01] joey doll <br>
 
[http://biomechanics.stanford.edu/me337/projects/gene_regulation01.pdf  p01] joey doll <br>
 
microgrowth
 
microgrowth
[http://biomechanics.stanford.edu/me337/projects/microgrowth01.pdf p01] amir shamloo
+
[http://biomechanics.stanford.edu/me337/projects/nair0X.pdf p01] amir shamloo

Revision as of 10:17, 22 May 2007

Contents

teaching in general

teaching_philosophy
lecture notes continnum mechanics - linear (download)
lecture notes finite element method - linear (download)
lecture notes finite element method - nonlinear (download)

current courses

me 337 - mechanics of growth
tue thu 3:15-4:30
mc cullough 126

goals

in contrast to traditional engineering structures living structures show the fascinating ability to grow and adapt their form, shape and microstructure to a given mechanical environment. this course addresses the phenomenon of growth on a theoretical and computational level and applies the resulting theories to classical biomechanical problems like bone remodeling, hip replacement, wound healing, atherosclerosis or in stent restenosis. this course will illustrate how classical engineering concepts like continuum mechanics, thermodynamics or finite element modeling have to be rephrased in the context of growth. having attended this course, you will be able to develop your own problem-specific finite element based numerical solution techniques and interpret the results of biomechanical simulations with the ultimate goal of improving your understanding of the complex interplay between form and function.

syllabus

day date topic slides homework
tue apr 03 introduction - different forms of growth s01 h01 wiki growth
thu apr 05 rep tensor calculus - tensor algebra s02
tue apr 10 rep tensor calculus - tensor analysis s03 h02 tensors
thu apr 12 kinematic equations s04
tue apr 17 balance equations – closed systems s05
thu apr 19 balance equations – open systems s06 example rocket propulsion
tue apr 24 constitutive equations – density growth s07 example astronaut
thu apr 26 constitutive equations – volume growth s08 example tumor growth
tue mai 01 finite element method – density growth theory s09
thu mai 03 finite element method – density growth matlab s10 matlab density
tue mai 08 examples – bone remodeling s11 example bone
thu mai 10 finite element method – density growth alternative s12
tue mai 15 finite element method – density growth discussion take-home assign
thu mai 17 no class ;-) projects
tue mai 22 kinematic equations – volume growth
thu mai 24 balance equations – volume growth galileo problem
tue mai 29 finite element method - volume growth theory wiki growth
thu mai 31 finite element method – volume growth matlab
tue jun 05 example – atherosclerosis, in stent restenosis s19
thu jun 07 wiki session – vote on articles

matlab files

voila!... just to get used to tensor notation and matlab
matlab_ex01.m ... the one with all the tensors

finally... here's the matlab nonlinear finite element code for density growth!
matlab_growth.tar ... the one where u got it all

or... if you prefer to look @all the individual files
i've tried to put comments to most of the variables, drop me an email if you want moooore ;-)
assm_sys.m ... the one with the strange big A operator
cnst_grw.m ... the one with the constitutive equations for growth
element1.m ... the one with the element residual and tangent
ex_frame.m ... the one with the example of the frame structure
ex_unity.m ... the one with the example of two elements
extr_dof.m ... the one which extracts element information from the global field
mesh_sqr.m ... the one which meshes a square domain
nlin_fem.m ... the one and only
plot_int.m ... the one to plot internal variables on the spatial/deformed configuration
plot_mat.m ... the one to plot the material/undeformed configuration
res_norm.m ... the one which tells you how far you are away from your ultimate goal
solve_nr.m ... the one with the solution to all problems
upd_dens.m ... the one with yet another newton iteration to calculate the density

bone example

if someone wanted to caluclate the bone example from the literature (2) and (3), here ex_bone1.m is the general data, but it's not yet cast into the matlab input format, so if you wanted to generate a real input file from it and convert it into q0, edof, bc and Fext, that would be great! most growth problems apply the load first in a number of time steps (here, i guess one step should be enough) and then apply another few (try about 50) time steps with a constant load to allow for density redistribution... you might have to change nlin_fem.m accordingly if you wanted to try that...

i know... the code's slow... so go'n get a cup of coffee... or try to re-code cnst_grw.m in terms of either spatial or material stresses & tangents by using voigt's matrix notation and speed up element1.m by using the traditional old-fashioned b-operator, it's maybe ugly in the code but a loaaad faster!

additional reading

don't feel forced to read all of this! it's just additional information that some of you might want to look at!

(1) taber l: biomechanics of growth, remodeling, and morphogenesis, appl mech rew 48, 487-545, 1995

(2) jacobs, cr, levenston me, beaupre gs, simo jc, carter dr: numerical instabilities in bone remodeling simulations: the advantages of a node-based finite element approach, j biomechanics 28, 449-459, 1995

(3) kuhl e, menzel a, steinmann p: computational modeling of growth - a critical review, a classification and two new consistent approaches, computational mechanics 32, 71-88, 2003

(4) rodriguez ek, hoger a, mc culloch a: stress-dependent finite growth in soft elastic tissues, j biomechanics 27, 455-467, 1994

(5) kuhl e, maas r, himpel g, menzel a: computational modeling of arterial wall growth - attempts towards patient-specific simulations based on computer tomography, biomech model mechanobiol, available online first, DOI 10.1007/s10237-006-0062-x

project related reading

density studies in tennisplayers p01 p02 p03 p04 rebecca taylor
more tennisplayers p05 p06 p07 p08 p09 p10 chun hua zheng
sophisticated growth law p01 joey doll
microgrowth p01 amir shamloo