Design in Nature: Learning from TreesThe chicken bone which you nibbled and threw away yesterday was a high-tech product! In fact it was a superlative light-weight design functionally adapted to the mechanical requirements. No engineer in the world has as yet been able to copy this structural member, which is excellently optimized in its external shape and its internal architecture as regards minimum weight and maximum strength. The tree trunk on which you recently carved your initials has also over the course of its life, steadily improved its internal and external structure and adapted itself optimally to new loads. In the course of its biomechanical self-optimization, it will heal the notch you cut as speedily as possible, in order to repair even the smallest weak point, which might otherwise cost it its life in the next storm. This book is dedicated to the understanding of this biomechanical optimization of shape. And not only that: With the knowledge of these perfect processes of self-optimization in nature, techniques for the improvement of mechanical structural members could be developed. Industry already uses them. Nature shows us the way to eco-design, to machines in accordance with nature's laws governing structures and shapes. CLAUS MATTHECK: Born in Dresden, Germany in 1947. Study of physics in Dresden, PhD in theoretical physics in 1973. Habilitation in the field of damage control in 1985. Lectures on biomechanics at the University of Karlsruhe. Head of the Department of Biomechanics of the Research Centre in Karlsruhe, where the results described in this book were obtained. Several awards in science and literature. |
Contents
The Minimum on Mechanics | 3 |
Thermal Expansion and Thermal Stresses | 11 |
The Finite Element Method FEM | 12 |
Notches and Notch Stresses | 14 |
Crack Propagation | 20 |
Overview of the Mechanics | 21 |
What Is a Good Mechanical Design? | 25 |
The Axiom of Uniform Stress and How Computer Methods Derive from It | 29 |
Failure of ThickWalled Wooden Tubes by CrossSectional Flattening | 142 |
The Tree as a ThinWalled Tube | 144 |
The Open CrossSection The LoadDependent Chameleon | 146 |
The Devils Ear | 147 |
Fatal Failure or Last Resort? | 148 |
The Wind Breakage of ShallowRooters | 157 |
Windthrow | 159 |
The Beginning of the End | 160 |
ComputerAided Optimization Growth in the Computer | 32 |
Away with the Ballast | 35 |
The StressIncrementControlled SKO Method | 39 |
Presentation of the Methods at a Glance | 41 |
The Mechanics of Trees and the SelfOptimization of Tree Shape | 43 |
The Top Rules | 44 |
The Quest for Light | 49 |
The Axiom of Uniform Stress and Tree Shape | 53 |
From the HighTech Connection to the Point of Potential Breakage | 58 |
Risk Only with Incorrect Loading | 61 |
The Tension Fork | 62 |
The Compression Fork | 64 |
Ingenious Anchors with a Penchant for Social Contacts | 67 |
Points of Potential Breakage are Speedily Repaired | 81 |
Mechanical Companionship with Inanimate Objects | 96 |
Species Difference as a Mechanical Handicap | 100 |
From First Kiss to LifeLong Marriage | 104 |
The Cross Weld | 106 |
Merciless Welding Artist | 112 |
Advantages of the Social Behaviour of Trees for the Species | 114 |
The Internal Diary as a Consequence of the External Situation | 115 |
Reaction Wood and Helical Grain in the Sawn Section | 116 |
The Sawn Section Through Healed Wounds | 117 |
The Sick Report of the Annual Rings | 118 |
A Dead Branch Is Treated Like a Steel Tube | 123 |
The Trees Marriage in the Sawn Section | 125 |
Summary of the Rules for Annual Ring Design | 127 |
The Fear of Shear Stress | 129 |
How Does a Tree Break? | 141 |
Can Trees Really Not Shrink? | 163 |
UltraLight and Very Strong by Continuous Optimization of Shape | 165 |
Selected Examples | 167 |
Healing of a Femur Fracture | 170 |
The Consequences of Hip Prostheses for the Femur | 172 |
The Vertebral Arch A Weak Point? | 175 |
MicroFrameworks as Pressure Distributor Dash Pot and LightWeight Internal Architecture | 177 |
The Wanderings of the Trabeculae in the Search for Pure Axial Loading | 178 |
Bony Frameworks and Tree Frameworks Compared | 183 |
The Reasons Why Bones Are Better at Adapting Their Shape | 184 |
ShapeOptimized by Success in the Lottery of Heredity | 185 |
Thorn Shape and Load Direction | 187 |
Biological Shells | 191 |
Why a Shell Theory Is Inadequate for Shape Optimization | 192 |
Tortoises and Nuts | 195 |
UltraLight but Highly Specialized | 199 |
A Functional Identity | 201 |
Buttress Roots from the Standpoint of Bracing | 202 |
Shape Optimization by Growth in Engineering Design | 209 |
Beam Shoulders | 213 |
Shape Optimization of ThreeDimensional Components | 214 |
Frameworks | 217 |
Design Target and Realization | 221 |
Sensitization by Specialization | 223 |
Ecodesign and ClosetoNature Computer Empiricism | 225 |
New Examples of Application in SelfExplanatory Illustrations | 227 |
271 | |
273 | |
Other editions - View all
Common terms and phrases
abductor adaptive growth angle of friction annual rings axial axiom of uniform beech bending load bending stresses biological biomechanical bone fractures bracing branch junction branch-shedding collar buckling buttress root CAO method cause component compression fork compressive stresses contact area crack Dagmar Gräbe decay deflection design area diameter direction ecodesign edge example failure femur force flow formation fracture framework geotropism hazard beam high low FEM horizontal root initial Karlsruhe Research Centre kinking later light-weight longitudinal material Matthias Teschner Fig maximum stress mechanical Mises stress high nature non-optimized optimized notch stresses optimum phototropism plate prosthesis reaction wood reduced sawn section shape shape-optimized shear stress shell shows side branch SKO method stem stress along contour stress distribution stress high low stress reduction structure surface tensile stresses thermal thickness trabecula trabecular bone transverse tree's trunk tube uniform stress upper vertebral arch vertical weld wind loading wood fibres wound healing wound spindle zones
Popular passages
Page vii - No engineer in the world has, as yet, been able to copy this structural member, which is excellently optimized in its external shape and its internal architecture as regards minimum weight and maximum strength.
Page vii - In the course of its biomechanical self-optimization it will heal up the notch you cut as speedily as possible, in order to repair even the smallest weak point, which might otherwise cost it its life in the next storm.