Andrew P Zeltwanger

07-22-1999, 04:34 AM

I am studying a recent paper that appeared in the June 1999 issue of the

Journal of Biomechanical Engineering by Y.P. Zheng and A.F.T. Mak. The

paper is entitled "Extraction of Quasi-Linear Viscoelastic Parameters for

Lower Limb Soft Tissues from Manual Indentation Experiment." This paper

is relative to the research on soft-tissue biomechanics currently being

undertaken at the University of Pittsburgh. My question concerns the

Hayes' indention solution for an infinite homogeneous elastic layer on a

rigid foundation.

After this equation is defined with a scaling factor that is a function of

Poisson's ratio and the aspect ratio (a/h) [where a is the indentor radius

and h is the original thickness of the tissue], the relative indention (u)

is defined as the ratio of the indention (w) to the original thickness.

At this point, the aspect ratio is REDEFINED as a/(h(1-u)). I don't

understand this redefinition. I don't believe that the two aspect ratios

are the same. I would greatly appreciate any help or reference that will

help me understand this bit of mathematics.

Andrew P. Zeltwanger

Department of Rehabilitation Science and Technology

University of Pittsburgh

apzst3+@pitt.edu

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Journal of Biomechanical Engineering by Y.P. Zheng and A.F.T. Mak. The

paper is entitled "Extraction of Quasi-Linear Viscoelastic Parameters for

Lower Limb Soft Tissues from Manual Indentation Experiment." This paper

is relative to the research on soft-tissue biomechanics currently being

undertaken at the University of Pittsburgh. My question concerns the

Hayes' indention solution for an infinite homogeneous elastic layer on a

rigid foundation.

After this equation is defined with a scaling factor that is a function of

Poisson's ratio and the aspect ratio (a/h) [where a is the indentor radius

and h is the original thickness of the tissue], the relative indention (u)

is defined as the ratio of the indention (w) to the original thickness.

At this point, the aspect ratio is REDEFINED as a/(h(1-u)). I don't

understand this redefinition. I don't believe that the two aspect ratios

are the same. I would greatly appreciate any help or reference that will

help me understand this bit of mathematics.

Andrew P. Zeltwanger

Department of Rehabilitation Science and Technology

University of Pittsburgh

apzst3+@pitt.edu

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To unsubscribe send SIGNOFF BIOMCH-L to LISTSERV@nic.surfnet.nl

For information and archives: http://isb.ri.ccf.org/biomch-l

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