Design in Nature : Learning from Trees

Introduction 1(2) The Minimum on Mechanics 3(22) External Loads and Internal Stresses 3(8) Thermal Expansion and Thermal Stresses 11(1) The Finite Element Method (FEM) 12(2) The Component Killers: Notches and Notch Stresses 14(6) Crack Propagation 20(1) Overview of the Mechanics 21(4) What Is a Good Mechanical Design? 25(4) The Axiom of Uniform Stress and How Computer Methods Derive from It 29(14) Notches Without Notch Stresses? 29(3) Computer-Aided Optimization -- Growth in the Computer 32(3) Soft Kill Option: Away with the Ballast! 35(2) Stress-Controlled E-Modulus Distribution 37(2) The Stress-Increment-Controlled SKO Method 39(2) Presentation of the Methods at a Glance 41(2) The Mechanics of Trees and the Self-Optimization of Tree Shape 43(10) The Controlling Mechanisms and Their Effect on the Tree 43(10) Apical Dominance: The Top Rules 44(1) Geotropism: Stand Up Straight! 44(5) Phototropism: The Quest for Light 49(4) The Right Load Distribution: The Axiom of Uniform Stress and Tree Shape 53(62) The Height-Diameter Ratio of the Trunk 53(5) Branch Junctions: From the High-Tech Connection to the Point of Potential Breakage 58(3) Tree Forks: Risk Only with Incorrect Loading 61(6) The Tension Fork 62(2) The Compression Fork 64(3) Roots: Ingenious Anchors with a Penchant for Social Contacts 67(14) Wound Healing: Points of Potential Breakage are Speedily Repaired 81(15) Tree-Stone Friendships: Mechanical Companionship with Inanimate Objects 96(4) Tree-Tree Contacts: Species Difference as a Mechanical Handicap 100(4) Tree Welds (Grafts): From First Kiss to Life-Long Marriage 104(10) The Axial Weld 104(2) The Cross Weld 106(6) The Strangler Fig: Merciless Welding Artist 112(2) Advantages of the Social Behaviour of Trees for the Species 114(1) Annual Rings: The Internal Diary as a Consequence of the External Situation 115(14) Reaction Wood and Helical Grain in the Sawn Section 116(1) The Sawn Section Through Healed Wounds 117(1) Frost Ribs: The Sick Report of the Annual Rings 118(5) Contact Reports: A Dead Branch Is Treated Like a Steel Tube 123(2) Welds: The Tree's Marriage in the Sawn Section 125(2) Summary of the Rules for Annual Ring Design 127(2) Wood Fibres and Force Flow: The Fear of Shear Stress 129(12) How Does a Tree Break? 141(22) Transverse Fracture of a Solid Cylinder 141(1) Failure of Thick-Walled Wooden Tubes by Cross-Sectional Flattening 142(2) Shell Buckling: The Tree as a Thin-Walled Tube 144(2) The Open Cross-Section -- The Load-Dependent Chameleon 146(1) The Devil's Ear 147(1) The Hazard Beam: Fatal Failure or Last Resort? 148(9) The Wind Breakage of Shallow-Rooters 157(2) Windthrow 159(1) Fibre Kinking: The Beginning of the End 160(3) Can Trees Really Not Shrink? 163(2) Bones: Ultra-Light and Very Strong by Continuous Optimization of Shape 165(2) Bone Design: Selected Examples 167(16) The Femur: Heavily Loaded and Successful 167(8) Healing of a Femur Fracture 170(2) The Consequences of Hip Prostheses for the Femur 172(3) The Vertebral Arch -- A Weak Point? 175(2) Trabecular Bone: Micro-Frameworks as Pressure Distributor, Dash Pot and Light-Weight Internal Architecture 177(6) Trabecula Axis and Force Flow: The Fear of Bending Load 177(1) Drifting and Rotating: The Wanderings of the Trabeculae in the Search for Pure Axial Loading 178(5) Bony Frameworks and Tree Frameworks Compared 183(2) Trabeculae and Air-Rooters 183(1) The Reasons Why Bones Are Better at Adapting Their Shape 184(1) Claws and Thorns: Shape-Optimized by Success in the Lottery of Heredity 185(6) The Tiger's Claw 185(2) Thorn Shape and Load Direction 187(4) Biological Shells 191(8) What Are Shell Structures? 191(1) Why a Shell Theory Is Inadequate for Shape Optimization 192(3) Tortoises and Nuts 195(4) Bracing: Ultra-Light but Highly Specialized 199(10) The Advantages of Bracing and Its Sensitivity to Loading Inappropriate to the Design 199(2) Bracing at the Hip-Joint and in Trees on Eroding Sites: A Functional Identity 201(1) Buttress Roots from the Standpoint of Bracing 202(7) Shape Optimization by Growth in Engineering Design 209(12) Plane or Rotationally Symmetrical Models 209(5) The Orthopaedic Screw 209(4) Beam Shoulders 213(1) Shape Optimization of Three-Dimensional Components 214(3) Shaft with Rectangular Aperture 214(3) Frameworks 217(4) Unity in Diversity: Design Target and Realization 221(2) Critique on Optimum Shape: Sensitization by Specialization 223(2) Outlook: Ecodesign and Close-to-Nature Computer Empiricism 225(2) New Examples of Application in Self-Explanatory Illustrations 227(44) References 271(2) Subject Index 273