10 Mechanical Properties of Biological
Materials
10.1 Introduction
The preceding two parts of this book were dedicated to the description of the
fundamentals of fluid mechanics (Part I), and oceanic physical processes of various scales, which are not usually considered in fluid mechanics textbooks (Part
II). This later field of fluid mechanics is known as geophysical fluid mechanics
(Cushman-Roisin, 1994).
Part III of this book is totally focused on the description of various linkages
between ocean water motions, given in the previous parts, and many aspects of
biological life in the ocean. However, as this book is focused on fluid mechanics,
the biological details will only be described to such an extent that is needed to
understand the role of the physical environment for the functioning of marine
animals. It is assumed that the reader has a basic knowledge of marine ecology.
At the beginning of Part III we will consider the mechanical properties of marine animals. The final size and shape of species are the result of many factors,
such as animal physiology, availability of food and location in the food chain,
as well as the characteristics of the physical environment in which the organism
lives. Marine animals adapt in different ways to live in turbulent, or laminar
environments. However, in each case an animal is subject to various environmental loadings (forces and moments). It should withstand these loadings by
developing appropriate body strength. In the next section we will describe
the main mechanical properties of marine animal bodies which determine the
animal's strength.
For marine species, whose weight is supported by immersion in water, the
relationship between the organism's density and the density of the surrounding
water is fundamental in determining the animal's motion with minimum usage
of energy. Aquatic organisms swim in a variety of ways and at a wide range
of speed, operating under notably different Reynolds number regimes. As a
result, they have developed remarkable methods of adaptation for different
purposes. In particular, to avoid sinking, the marine species must either use
S. R. Massel, Fluid Mechanics for Marine Ecologists
© Springer-Verlag Berlin Heidelberg 1999
Materials
10.1 Introduction
The preceding two parts of this book were dedicated to the description of the
fundamentals of fluid mechanics (Part I), and oceanic physical processes of various scales, which are not usually considered in fluid mechanics textbooks (Part
II). This later field of fluid mechanics is known as geophysical fluid mechanics
(Cushman-Roisin, 1994).
Part III of this book is totally focused on the description of various linkages
between ocean water motions, given in the previous parts, and many aspects of
biological life in the ocean. However, as this book is focused on fluid mechanics,
the biological details will only be described to such an extent that is needed to
understand the role of the physical environment for the functioning of marine
animals. It is assumed that the reader has a basic knowledge of marine ecology.
At the beginning of Part III we will consider the mechanical properties of marine animals. The final size and shape of species are the result of many factors,
such as animal physiology, availability of food and location in the food chain,
as well as the characteristics of the physical environment in which the organism
lives. Marine animals adapt in different ways to live in turbulent, or laminar
environments. However, in each case an animal is subject to various environmental loadings (forces and moments). It should withstand these loadings by
developing appropriate body strength. In the next section we will describe
the main mechanical properties of marine animal bodies which determine the
animal's strength.
For marine species, whose weight is supported by immersion in water, the
relationship between the organism's density and the density of the surrounding
water is fundamental in determining the animal's motion with minimum usage
of energy. Aquatic organisms swim in a variety of ways and at a wide range
of speed, operating under notably different Reynolds number regimes. As a
result, they have developed remarkable methods of adaptation for different
purposes. In particular, to avoid sinking, the marine species must either use
S. R. Massel, Fluid Mechanics for Marine Ecologists
© Springer-Verlag Berlin Heidelberg 1999