Not so much a bag of roots as a can of worms . . .
The roots will be viscoelastic, so you can get almost any result if you're not
careful. Probably best to start off characterising the hysteresis behaviour
(simple loading and unloading) trying to make the mechanical deformations as
similar as possible to the ones you think the plant is normally subjected to,
plus a bit. Pay particular attention to the speed at which you do the
deformations; also the temperature. A change in temperature of 8 degrees C is
about equivalent to a change in strain rate of an order of magnitude (higher
temperature == slower strain rate).
One of the best introductions to viscoelasticity I know is in the 1980 SEB
symposium on Biological Materials - chapter by Keith Dorrington.
Julian
Adrian M Goodman wrote:
> Dear All
> Apologies to anyone who has received this message twice. I would be very
> grateful for any advice on suitable methods for calculating the resilience
> of biological materials. More specifically I am interested in carrying out
> some load relaxation tests on the roots of Galium aparine (cleavers). A few
> preliminary results suggests that the lateral roots can undergo strains of
> between 20-30% before failure. I want to investigate this further by
> carrying out some more tests to measure the resilience (strain energy
> storage?). My dilemma is that I am unsure of when to start unloading the
> specimen. Any suggestions on whether it would be best to use a set
> extension or perhaps unload once the material has reached its elastic limit
> would be most welcome.
>
> Many thanks
> from
> Adrian
> ----------------------------------------------------------------------------
> ------------
> Dr Adrian Goodman
> De Montfort University Lincoln
> School of Agriculture
> Riseholme
> Lincoln LN2 2LG
> UK
> Tel: 01522 895370
> Fax: 01522 545436
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