STRUCTURALMODELING

ANDEXPERIMENTAL

TECHNIQUESSECOND EDITION

Harry G. Harris. Drexel University

Philadelphia, Pennsylvania

and

Gajanan M. SabnisHoward UniversityWashington, D.C.

CRC PressBoca Raton London New York Washington, D.C.

Table of Contents

Chapter 1 Introduction to Physical Modeling in Structural Engineering1.1 Introduction 11.2 Structural Models Definitions and Classifications 21.3 A Brief Historical Perspective on Modeling 61.4 Structural Models and Codes of Practice 71.5 Physical Modeling and the New Engineering Curriculum 81.6 Choice of Geometric Scale 91.7 The Modeling Process 101.8 Advantages and Limitations of Model Analysis 111.9 Accuracy of Structural Models 121.10 Model Laboratories 131.11 Modeling Case Studies 131.12 Summary 34Problems 36References 37

Chapter 2 The Theory of Structural Models2.1 Introduction 422.2 Dimensions and Dimensional Homogeneity 422.3 Dimensional Analysis 452.4 Structural Models 562.5 Similitude Requirements 622.6 Summary 76Problems 77References . 81

Chapter 3 Elastic Models - Materials and Techniques3.1 Introduction 863.2 Materials for Elastic Models 873.3 Plastics 883.4 Time Effects in Plastics Evaluation and Compensation 963.5 Effects of Loading Rate, Temperature, and the Environment 1003.6 Special Problems Related to Plastic Models 1033.7 Wood and Paper Products 1043.8 Elastic Models Design and Research Applications 1213.9 Determination of Influence Lines and Influence Surfaces Using Indirect

Models Miiller-Breslau Principle 1213.10 Summary 123Problems 124References 127

Chapter 4 Inelastic Models: Materials for Concrete and ConcreteMasonry Structures4.1 General 1304.2 Prototype and Model Concretes 1304.3 Engineering Properties of Concrete 1314.4 Unconfined Compressive Strength and Stress-Strain Relationship 1334.5 Tensile Strength of Concrete 1424.6 Flexural Behavior of Prototype and Model Concrete 1464.7 Behavior in Indirect Tension and Shear 1484.8 Design Mixes for Model Concrete 1534.9 Summary of Model Concrete Mixes Used by Various Investigators 1594.10 Gypsum Mortars 1654.11 Modeling of Concrete Masonry Structures 1704.12 Strength of Model Block Masonry Assemblages 1884.13 Summary 202Problems 202References 205

Chapter 5 Inelastic Models: Structural Steel and Reinforcing Bars5.1 Introduction 2105.2 Steel 2105.3 Structural Steel Models 2145.4 Reinforcement for Small-Scale Concrete Models 2305.5 Model Prestressing Reinforcement and Techniques 2525.6 FRP Reinforcement for Concrete Models 2555.7 Bond Characteristics of Model Steel 2595.8 Bond Similitude 2665.9 Cracking Similitude and General Deformation Similitude in Reinforced

Concrete Elements 2675.10 Summary 272Problems 272References 274

Chapter 6 Model Fabrication Techniques6.1 Introduction 2806.2 Basic Cutting, Shaping, and Machining Operations 2816.3 Basic Fastening and Gluing Techniques 2836.4 Construction of Structural Steel Models 2876.5 Construction of Plastic Models 2886.6 Construction of Wood and Paper Models 2966.7 Fabrication of Concrete Models 2996.8 Fabrication of Concrete Masonry Models 3096.9 Summary 312Problems 312References 315

Chapter 7 Instrumentation Principles and Applications7.1 General 3207.2 Quantities to be Measured 3207.3 Strain Measurements.: 3227.4 Displacement Measurements 3487.5 Full-Field Strain Measurements and Crack Detection Methods 3517.6 Stress and Force Measurement 3537.7 Temperature Measurements 3617.8 Creep and Shrinkage Characteristics and Moisture Measurements 3627.9 Data Acquisition and Reduction 3647.10 Fiber Optics and Smart Structures 3677.11 Summary 377Problems 377References 381

Chapter 8 Loading Systems and Laboratory Techniques8.1 Introduction 3838.2 Types of Loads and Loading Systems 3848.3 Discrete vs. Distributed Loads 3898.4 Loadings for Shell and Other Models 3908.5 Loading Techniques for Buckling Studies and For Structures Subject to Sway 4008.6 Miscellaneous Loading Devices 4048.7 Summary 407Problems 407References 409

Chapter 9 Size Effects, Accuracy, and Reliability in Materials Systems and Models9.1 General 4129.2 What Is a Size Effect? 4149.3 Factors Influencing Size Effects 4149.4 Theoretical Studies of Size Effects 4159.5 Size Effects in Plain ConcreteExperimental Work 4209.6 Size Effects in Reinforced and Prestressed Concrete 4319.7 Size Effects in Metals and Reinforcements 4339.8 Size Effects in Masonry Mortars 4349.9 Size Effects and Design Codes 4359.10 Errors in Structural Model Studies 4379.11 Types of Errors 4399.12 Statistics of Measurements 4419.13 Propagation of Random Errors 4449.14 Accuracy in (Concrete) Models 4509.15 Overall Reliability of Model Results 4579.16 Influence of Cost and Time on Accuracy of Models 4589.17 Summary 458Problems 459References 460

Chapter 10 Model Applications and Case Studies10.1 Introduction 46610.2 Modeling Applications 46610.3 Case Studies 52910.4 Summary 572Problems 573References 579

Chapter 11 Structural Models for Dynamic Loads11.1 Introduction 58611.2 Similitude Requirements 58711.3 Materials for Dynamic Models 58811.4 Loading Systems for Dynamic Model Testing 59311.5 Examples of Dynamic Models 60411.6 Case Studies 64911.7 Summary 673Problems 673References 675

Chapter 12 Educational Models for Civil and Architectural Engineering12.1 Introduction 68012.2 Historical Perspective 68112.3 Linearly Elastic Structural Behavior 68112.4 Nonlinear and Inelastic Structural Behavior 69412.5 Structural Dynamics Concepts 71212.6 Experimentation and the New Engineering Curriculum 72512.7 Case Studies and Student Projects 72912.8 Summary 751Problems 752References 753

Appendix A Dimensional Dependence and IndependenceA.I The Form of Dimensions 757A.2 Method I: The Numeric Method 759A.3 Method II: The Functional Method 761A.4 Illustrative Examples 763References 766

Appendix B A Note on the Use of SI Units in Structural EngineeringB.I Geometry 768B.2 Densities, Gravity Loads, Weights 768B.3 Force, Moment, Stress, and Other Stress Resultants 768B.4 Miscellaneous (Angles, Temperature, Energy, Power) 768B.5 SI System Standard Practice 769

Index 771