This text introduces and explores many core topics in the field of applied mechanics. On the basis of Lagrange's Principle, it presents a Central Equation of Dynamics that yields a unified view on existing methods in dynamics.
1. Background This textbook is an introduction to and exploration of a number of core topics in the ?eld of applied mechanics. Mechanics, in both its theoretical and applied contexts, is, like all scienti?c endeavors, a human construct. It re?ects the personalities, thoughts, errors, and successes of its creators. We therefore provide some personal information about each of these individuals when their names arise for the ?rst time in this book. This should enable the reader to piece together a cultural-historical picture of the ?eld s origins and development. This does not mean that we are writing history. Nevertheless, some remarks putting individuals and ideas in context are necessary in order to make clear what we are speaking about and what we are not speaking about. At the end of the 19th century, technical universities were established eve- where in Europe in an almost euphoric manner. But the practice of technical mechanics itself, as one of the basics of technical development, was in a desolate state, due largely to the refusal of its practitioners to recognize the in?uence of kinetics on motion. They were correct to the extend that then current mechanical systems moved with small velocities where kinetics does not play a signi?cant role. But they had failed to keep up with developments in the science underlying their craft and were unable to keep pace with the speeds of such systems as the steam engine.
Unified view on methods in dynamics
Straight-on generic procedure for rigid and elastic multibody systems
Clearly structured mathematical representation
Easy physical insight and interpretation
Simple algorithms for direct computer useInhalt
1. INTRODUCTION; 1.1 Background; 1.2 Contents; 2. AXIOMS AND PRINCIPLES; 2.1 Axioms; 2.2 Principles the 'Differential' Form; 2.3 Minimal Representation; 2.3.1 Virtual Displacements and Variations; 2.3.2 Minimal Coordinates and Minimal Velocities; 2.3.3 The Transitivity Equation; 2.4 The Central Equation of Dynamics; 2.5 Principles the 'Minimal' Form; 2.6 Rheonomic and Non-holonomic Constraints; 2.7 Conclusions; 3. KINEMATICS; 3.1 Translation and Rotation; 3.1.1 Rotation Axis and Rotation Angle; 3.1.2 Transformation Matrices; 18.104.22.168 Rotation Vector Representation; 22.214.171.124 Cardan Angle Representation; 126.96.36.199 Euler Angle Representation; 3.1.3 Comparison; 3.2 Velocities; 3.2.1 Angular Velocity; 188.8.131.52 General Properties; 184.108.40.206 Rotation Vector Representation; 220.127.116.11 Cardan Angle Representation; 18.104.22.168 Euler Angle Representation; 3.3 State Space; 3.3.1 Kinematic Differential Equations; 22.214.171.124 Rotation Vector Representation; 126.96.36.199 Cardan Angle Representation; 188.8.131.52 Euler Angle Representation; 3.3.2 Summary Rotations; 3.4 Accelerations; 3.5 Topology the Kinematic Chain; 3.6 Discussion; 4. RIGID MULTIBODY SYSTEMS; 4.1 Modeling aspects; 4.1.1 On Mass Point Dynamics; 4.1.2 The Rigidity Condition; 4.2 Multibody Systems; 4.2.1 Kinetic Energy; 4.2.2 Potentials; 184.108.40.206 Gravitation; 220.127.116.11 Springs; 4.2.3 Rayleigh's Function; 4.2.4 Transitivity Equation; 4.2.5 The Projection Equation; 4.3 The Triangle of Methods; 4.3.1 Analytical Methods; 4.3.2 Synthetic Procedure(s); 4.3.3 Analytical vs. Synthetic Method(s); 4.4 Subsystems; 4.4.1 Basic Element: The Rigid Body; 18.104.22.168 Spatial Motion; 22.214.171.124 Plane Motion; 4.4.2 Subsystem Assemblage; 126.96.36.199 Absolute Velocities; 188.8.131.52 Relative Velocities; 184.108.40.206 Prismatic Joint/Revolute Joint Spatial Motion; 4.4.3 Synthesis; 220.127.116.11 Minimal Representation; 18.104.22.168 Recursive Representation; 4.5 Constraints; 4.5.1 Inner Constraints; 4.5.2 Additional Constraints; 22.214.171.124 Jacobi Equation;126.96.36.199 Minimal Representation; 188.8.131.52 Recursive Representation; 184.108.40.206 Constraint Stabilization; 4.6 Segmentation: Elastic Body Representation; 4.6.1 Chain and Thread (Plane Motion); 4.6.2 Chain, Thread, and Beam; 4.7 Conclusion; 5. ELASTIC MULTIBODY SYSTEMS THE PARTIAL DIFFERENTIAL EQUATIONS; 5.1 Elastic Potential; 5.1.1 Linear Elasticity; 5.1.2 Inner Constraints, Classification of Elastic Bodies; 5.1.3 Disk and Plate; 5.1.4 Bea; 5.2 Kinetic Energy; 5.3 Checking Procedures; 5.3.1 HAMILTON's Principle and the Analytical Methods; 5.3.2 Projection Equation; 5.4 Single Elastic Body Small Motion Amplitudes; 5.4.1 Beams; 5.4.2 Shells and Plates; 5.5 Single Body Gross Motion; 5.5.1 The Elastic Rotor; 5.5.2 The Helicopter Blade (1); 5.6 Dynamical Stiffening; 5.6.1 The CAUCHY Stress Tensor; 5.6.2 The TREFFTZ (or 2nd Piola-Kirchhoff) Stress Tensor; 5.6.3 Second-Order Beam Displacement Fields; 5.6.4 Dynamical Stiffening Matrix; 5.6.5 The Helicopter Blade (2); 5.7 Multibody Systems Gross Motion; 5.7.1 The Kinematic Chain; 5.7.2 Minimal Velocities; 5.7.3 Motion Equations; 220.127.116.11 Dynamical Stiffening; 18.104.22.168 Equations of Motion; 5.7.4 Boundary Conditions; 5.8 Conclusion; 6. ELASTIC MULTIBODY SYSTEMS THE SUBSYSTEM ORDINARY DIFFERENTIAL EQUATIONS; 6.1 Galerkin Method; 6.1.1 Direct Galerkin Method; 6.1.2 Extended Galerkin Method; 6.2 (Direct) Ritz Method; 6.3 Rayleigh Quotient; 6.4 Single Elastic Body Small Motion Amplitudes; 6.4.1 Plate; 22.214.171.124 Equations of motion; 126.96.36.199 Basics;; 188.8.131.52 Shape Functions: Spatial Separation Approach; 184.108.40.206 Expansion in Terms of Beam Functions; 220.127.116.11 Convergence and Solution; 6.4.2 Torsional Shaft; 18.104.22.168 Eigenfunctions; 22.214.171.124 Motion Equations; 126.96.36.199 Shape Functions; 6.4.3 Change-Over Gear; 6.5 Single Elastic Body Gross Motion; 6.5.1 The Elastic Rotor; 188.8.131.52 Rheonomic Constraint; 184.108.40.206 Choice of Shape Functions Prolate Rotor ( = 0); 220.127.116.11 Choice of Shape Functions Oblate