Testing and Modeling of Cellular Materials

Description

Testing and Modeling of Cellular Materials discusses the characterization of cellular lattices through quasi-static and dynamic testing for use in light-weighting or energy-absorbing applications. Covering cellular materials, specifically additively manufactured lattices, this book further progresses into dynamic testing and modeling techniques for computational simulations. It presents modeling and simulation techniques used for cellular materials and evaluates them against experimental results to illustrate the material response under various conditions. The book also includes a case study of high-velocity impact that highlights the high strain rate effects on the cellular lattices. Features: • Covers different testing techniques used in quasi-static and dynamic material characterization of cellular materials. • Discusses additive manufacturing techniques for lattice specimen fabrication. • Analyzes different finite element modeling techniques for quasi-static and dynamic loading conditions. • Presents a comparison and development of a phenomenological material model for use in computational analysis at various loading rates. • Explores impact stress wave analysis under high-velocity loading. The book will be useful for researchers and engineers working in the field of materials modeling and mechanics of materials. Cover Half Title Title Page Copyright Page Table of Contents List of Figures Preface Authors Acronyms Chapter 1 Introduction 1.1 Overview 1.2 Research Objectives 1.2.1 Research Objective 1: Characterize Quasi-Static Material Properties of Cellular Designs 1.2.2 Research Objective 2: Characterize Dynamic Material Properties of Cellular Designs 1.2.3 Research Objective 3: Develop Computational Model and Impact Simulation 1.2.4 Research Objective 4: Evaluate Inclusion of Cellular Structures on Impact Results 1.3 Background 1.3.1 Cellular Structures 1.3.1.1 Terminology 1.3.1.2 Classification 1.3.1.3 Mechanical Properties 1.3.1.4 Triply Periodic Minimal Surface (TPMS) 1.3.2 Manufacturing Methods 1.3.2.1 Additive Manufacturing Methods 1.3.3 Impact Modeling and Simulation 1.3.3.1 Discrete Element Method 1.3.3.2 Finite Element Method 1.4 Organization of Subsequent Chapters References Chapter 2 Background Theory 2.1 Finite Element Method 2.1.1 Finite Element Method Theory 2.1.2 Smoothed Particle Hydrodynamics 2.1.3 Shock Waves and Equation of State 2.1.3.1 Shock Waves 2.1.3.2 Equation of State 2.2 Damage Modeling 2.2.1 Johnson–Cook Failure Model 2.2.2 Holmquist–Johnson–Cook Failure Model 2.3 Constitutive Models 2.3.1 Constitutive Compression Response Models 2.3.1.1 Rusch Model 2.3.1.2 Gibson Modified Model References Chapter 3 Experimental Methodology 3.1 Introduction 3.2 Mechanical Testing 3.2.1 Test Specimen Fabrication 3.2.2 Compression Test 3.2.2.1 Test Equipment 3.2.2.2 Test Procedures 3.2.2.3 Data Reduction 3.2.3 Taylor Impact Test 3.2.3.1 Test Equipment 3.2.3.2 Test Procedures 3.2.3.3 Data Reduction 3.2.4 Split Hopkinson Pressure Bar Test Results 3.2.4.1 Test Equipment 3.2.4.2 Test Procedures 3.3 Computation Methods 3.3.1 Johnson–Cook Damage Model Parameters 3.3.2 Impact Model and Analysis 3.3.2.1 Projectile 3.3.2.2 Target 3.3.2.3 Model Assembly 3.4 Topology Optimization 3.4.1 Optimization Overview 3.4.2 Multiscale Model 3.4.3 Topology Optimization Methods 3.4.3.1 Bi-directional Evolutionary Structural Optimization 3.4.3.2 Solid Isotropic Material and Penalization Method References Chapter 4 Uniaxial Compression of Lattices 4.1 Uniaxial Compression of Cylinders 4.2 Uniaxial Compression of Cubes References Chapter 5 Mechanical Properties of Lattices and Design Variations 5.1 Microstructural Assessment 5.2 Mechanical Properties of As-Built Lattices 5.3 Deformation Behavior References Chapter 6 Split Hopkinson Pressure Bar Test Results 6.1 Quasi-Static Mechanical Properties of Triply Periodic Minimal Surface Lattices 6.2 Dynamic Mechanical Properties of Triply Periodic Minimal Surface Lattices 6.3 Plasticity Model Parameters References Chapter 7 Strain Rate–Sensitive Constitutive Model for Lattice Structure 7.1 Legacy Material Models 7.1.1 Quasi-Static Response Models 7.1.2 Dynamic Response Models 7.2 Proposed Flow Stress Model 7.2.1 Model Development 7.2.2 Determination of Model Parameters 7.3 Results and Discussion 7.3.1 Quasi-Static Comparison 7.3.2 Dynamics Comparison References Chapter 8 Lattice Damage Model 8.1 Damage Model Parameter Determination 8.2 Damage Model Validation References Chapter 9 Computational Modeling Techniques and Results 9.1 Computational Impact Model 9.2 Full Lagrangian Models 9.3 Mixed Smoothed Particle Hydrodynamics–Lagrangian Model 9.4 Further Comparison of Models References Chapter 10 Projectile Impact Results 10.1 Experimental Projectile Impact 10.2 Computational Projectile Impact 10.3 Comparison of Experimental and Computational Results Reference Chapter 11 Conclusions 11.1 Summary of Conclusions References Appendix A TPMS Lattice Structure Generation Code, MATLAB Index