10 - examples density growth
10 - examples
1
different load cases
[1] midstance phase of gait 2317 N 24˚
[2] extreme range of
1158 N -15˚
[3] abduction
extreme range of adduction
1548 N 56˚
703 N 28˚
351 N -8 ˚
468 N 35˚
Carter & Beaupré [2001]
example - adaptation in bone
2
different load cases
combination of all load cases necessary
Carter & Beaupré [2001]
example - adaptation in bone
3
experiment vs simulation
• dense system of compressive trabaculae carrying stress into calcar
region
• secondary arcuate system, medial joint surface to lateral metaphyseal
region
• ward‘s triangle, low density region contrasting dense cortical shaft
Carter & Beaupré [2001]
example - adaptation in bone
4
node point based - h-refinement
example - adaptation in bone
5
node point based - p-refinement
example - adaptation in bone
6
integration point based - p-refinement
example - adaptation in bone
7
parameter sensitivity - instabilities
certain parameters induce checkerboard
Harrigon &
Hamilton [1992],[1994]
modes
example - adaptation in bone
8
comparison with x-rays
coxa vara
coxa
norma
Pauwels [1973]
coxa
valga
excellent agreement of simulation and xray pattern
example - adaptation in bone
9
total hip replacement vs hip resurfacing
• about 120,000 artificial hip replacements in us per
year
• aseptic loosening caused by adaptive bone
• goal prediction of dredisctribution of bone density
remodeling
example - hip replacement
10
convential total hip replacement
ward‘s triangle • trabeculae • dense cortical
shaft
example - hip replacement
11
convential total hip replacement
stress shielding • bone resorption • implang
loosening
example - hip replacement
12
new birmingham hip resurfacing
ward‘s triangle • trabeculae • dense cortical
shaft
example - hip replacement
13
new birmingham hip resurfacing
improved ingrowth • anatomic situation • less
resorption
example - hip replacement
14
computer tomography of human femur
patient specific medical treatment
example - hip replacement
15
wound healing
Murray [2003]
• epidermal migration / spreading of existing cells
• increase of mitotic activity of about15 times in 1mm
wide zone @wound edge
example - wound healing
16
wound healing
Edwin Smith Surgical Papyrus [13th Dynasty]
„…thou shouldst bind it with fresh meet the first day,
and thou shouldst treat afterword with grease and
honey every day until he recovers…“
Breadsted [1930]
example - wound healing
17
tension - single edge notched specimen
example - wound healing
18
tension - single edge notched specimen
increased cell activity @wound edge
example - wound healing
19
tension - surface cut specimen
increased cell activity @wound edge
example - wound healing
20
tension - crack mouth opening displacement
increased cell activity - wound healing &
closure
example - wound healing
21
bending - single edge notched specimen
increased cell activity @wound edge
example - wound healing
22
bending - surface cut specimen
increased cell activity @wound edge
example - wound healing
23
bending - crack mouth opening displacement
increased cell activity - wound healing &
closure
example - wound healing
24
form follows function
optimal
load case I
load case II
material distribution I
structural design
example - topology optimization
25
form follows function
bicycle frames 1817-2005
example - topology optimization
26
form follows function
a dna ™emiTk ciuQ
ro s se rpmo ced )de s serpmo cnU ( FFIT
.erut cip siht ee s ot dedeen era
Armstrong [2005]
design of bicycle frame
Kuhl
[2005]
example - topology optimization
27