Solid Biomechanics is the first book to comprehensively review the mechanical design of organisms. With a physical approach and a minimum of mathematics, the textbook introduces readers to the world of structural mechanics and sheds light on the dazzling array of mechanical adaptations that link creatures as dissimilar as bacteria, plants, and animals. Exploring a wide range of subjects in depth, from spider silks and sharkskin to climbing plants and human food processing, this immensely accessible text demonstrates that the bodies of animals and plants are masterpieces of engineering, enabling them to survive in a hostile world. The textbook describes how organisms construct materials from limited components, arrange materials into efficient structures that withstand different types of stresses, and interact mechanically with their environment. Looking at practical and historical aspects of the subject, the book delves into how the mechanics of organisms might be applied to other engineering scenarios and considers the ways structural biomechanics could and should develop in the future if more is to be learned about the form and function of organisms.
Solid Biomechanics will be useful to all those interested in how organisms work, from biologists and engineers to physicists and students of biomechanics, bionics, and materials science. * The first comprehensive review of the structural mechanics of organisms * Introduces the subject using a physical approach involving minimal mathematics * Three complementary sections: materials, structures, and mechanical interactions of organisms * Links the dazzling array of mechanical adaptations seen in widely differing organisms * Practical and historical approach shows how mechanical adaptations have been discovered and how readers can perform their own investigations
Roland Ennos is a reader in ecology at the University of Manchester. He is the author of "Trees".
Preface xi Acknowledgments xiii PART 1 Understanding Elasticity Chapter 1: The Properties of Materials 3 Forces: Dynamics and Statics 3 Investigating the Mechanical Properties of Materials 4 Determining Material Properties 7 Loading, Unloading, and Energy Storage 8 The Effect of Direction 11 Changes in Shape during Axial Loading 11 Shear 12 Performing Material Tests 14 Failure and Breaking 17 Stress Concentrations and Notch Sensitivity 17 Energy Changes and the Work of Fracture 19 Measuring Work of Fracture 21 Comparing the Properties of Materials 24 PART 2 Biological Materials Chapter 2: Biological Rubbers 29 The Problem of Raw Materials 29 Biological Polymers 30 The Shape and Behavior of Random-Coil Chains 32 The Structure and Mechanical Properties of Rubbers 32 Biological Protein Rubbers 35 Resilin 35 Abductin 37 Elastin 38 Chapter 3: Complex Polymers 42 The Mechanics of Polymers 42 Investigating Polymer Behavior 44 A Typical Polymer: Sea Anemone Mesoglea 46 Mucus and Gels 48 Making Protein Polymers Stiffer 51 Silks 53 Chapter 4: Polymer Composites 59 Combining Materials 59 The Behavior of Soft Composites 59 Natural Soft Composites 62 Rigid Composites 66 Keratinous Structures 68 The Theory of Fillers and Discontinuous Composites 74 Insect Cuticle 75 The Plant Cell Wall 79 Wood 80 Chapter 5: Composites Incorporating Ceramics 83 The Advantages of Incorporating Minerals 83 Spicule-Reinforced Connective Tissue 83 Bone 84 Tooth Ceramics 88 Mollusk Shell 89 PART 3 Biological Structures Chapter 6: Tensile Structures 95 An Introduction to Structures 95 Ropes and Strings 95 Using Multiple Ropes 97 Membranes, Skins, and Plates 98 Resisting Out-of-Plane Forces 102 Stresses in Pipes, Cylinders, and Spheres 103 The Design of Arteries 105 The Design of Lungs 107 The Design of Swim Bladders 108 The Design of Gas Vesicles 109 Chapter 7: Hydrostatic Skeletons 111 The Advantages of Being Pressurized 111 Cartilage 111 The Hydrostatic Skeletons of Plants 112 Cylindrical Pressure Vessels 113 Pressure Vessels with Orthogonal Fibers 113 Muscular Hydrostats 115 Helically Wound Cylinders 115 Helical Fibers to Control Growth and Shape 116 Helical Fibers as Muscle Antagonists 119 Fibers as Limits to Movement 121 Chapter 8: Structures in Bending 123 The Complexity of Bending 123 Simple Beam Theory 123 The Four-Point Bending Test 125 The Three-Point Bending Test 126 The Consequences of Simple Beam Theory 128 Fracture in Bending 134 Shear in Beams 135 The Consequences of Shear 138 Biological Trusses 139 Optimal Taper and the Scaling of Cantilever Beams 143 Chapter 9: Structures in Compression 147 Material Failure in Compression 147 Structural Failure in Compression 147 The Buckling of Struts 148 Buckling within Structures 152 Cork 157 Chapter 10: Structures in Torsion 159 Torsional Stresses and Strains 159 Torsion Tests 160 The Effect of Cross Section 162 Designs That Resist Torsion 162 Designs That Facilitate Torsion 163 The Mechanics of Spiral Springs 165 The Torsional Rigidity of Plates 166 Chapter 11: Joints and Levers 170 Support and Flexibility 170 Passive Movement in Plants 170 Active Movement in Plants 171 Hinges in Animals 172 Moving Joints 175 PART 4 Mechanical Interactions Chapter 12: Attachments 183 Holding On 183 Hooking On 183 Attachments to Soft Substrates 184 Attachments to Particulate Substrates 185 Attachments to Hard, Flat Surfaces 189 Chapter 13: Interactions with the Mechanical Environment 198 Optimizing Design for Strength 198 Factors of Safety 198 How Optimization is Achieved 201 Chapter 14: Mechanical Interactions between Organisms 206 Biotic Interactions 206 The Mechanics of Climbing Plants 206 The Mechanics of Fungal Hyphae and Appressoria 209 Plant Defenses against Fungi 210 Food Processing by Animals 210 Adaptations of Potential Food 212 Other Biotic Interactions 215 PART 5 Looking Forward Chapter 15: The Future of Structural Biomechanics 219 Successes 219 Limitations and Future Developments 219 New Frontiers for Biomechanics 222 Glossary 223 References 231 Index 247