Mechanics of Materials Laboratory Course

Description

This book is designed to provide lecture notes (theory) and experimental design of major concepts typically taught in most Mechanics of Materials courses in a sophomore- or junior-level Mechanical or Civil Engineering curriculum. Several essential concepts that engineers encounter in practice, such as statistical data treatment, uncertainty analysis, and Monte Carlo simulations, are incorporated into the experiments where applicable, and will become integral to each laboratory assignment. Use of common strain (stress) measurement techniques, such as strain gages, are emphasized. Application of basic electrical circuits, such as Wheatstone bridge for strain measurement, and use of load cells, accelerometers, etc., are employed in experiments. Stress analysis under commonly applied loads such as axial loading (compression and tension), shear loading, flexural loading (cantilever and four-point bending), impact loading, adhesive strength, creep, etc., are covered. LabVIEW software with relevant data acquisition (DAQ) system is used for all experiments. Two final projects each spanning 2?3 weeks are included: (i) flexural loading with stress intensity factor determination and (ii) dynamic stress wave propagation in a slender rod and determination of the stress?strain curves at high strain rates. The book provides theoretical concepts that are pertinent to each laboratory experiment and prelab assignment that a student should complete to prepare for the laboratory. Instructions for securing off-the-shelf components to design each experiment and their assembly (with figures) are provided. Calibration procedure is emphasized whenever students assemble components or design experiments. Detailed instructions for conducting experiments and table format for data gathering are provided. Each lab assignment has a set of questions to be answered upon completion of experiment and data analysis. Lecture notes provide detailed instructions on how to use LabVIEW software for data gathering during the experiment and conduct data analysis. Preface......Page 19 Dynamic Data Acquisition and Uncertainty in Measurements......Page 23 Statistical Treatment of Data and Uncertainty in Measurements......Page 24 Statistical Data Representation of Infinite Data......Page 26 Statistical Data Representation for Finite Data......Page 29 Uncertainty Analysis......Page 33 Equipment and Resources Needed......Page 39 Why Are We Doing This?......Page 40 Connections Required......Page 41 Experimental Task for Part 1......Page 42 Required LabVIEW Program......Page 43 Issues to be Discussed in the Lab Report for Part 2......Page 44 Required LabVIEW VI......Page 45 Experimental Task for Part 3......Page 46 Issues to be Discussed in the Lab Report for Part 3......Page 49 Equipment Requirements and Sourcing......Page 50 Appendix A: Part 1 – Preparing VI......Page 52 Abstract......Page 73 Procedure......Page 74 Discussion......Page 75 General Format......Page 76 Design and Build a Transducer to Measure the Weight of an Object......Page 79 Cantilever Beam Theory......Page 80 Strain Gage Theory......Page 82 Wheatstone-Bridge......Page 84 Calibration of the Transducer......Page 90 Determine the Weight of the Bottle Using the MOM Method......Page 91 Calibration Curve Method (CCM)......Page 92 Half-bridge (1/2-Bridge)......Page 96 Full-bridge......Page 97 Micrometer......Page 98 Equipment and Supplies Needed......Page 101 Required LabVIEW Program (VI)......Page 102 Experimental Task......Page 103 Issues to be Discussed in the Lab Report......Page 106 Appendix: Monte Carlo Simulation to Estimate Uncertainty in a Linear Fit......Page 107 Stress–Strain Response of Materials......Page 109 Introduction......Page 110 Load-based Stress–Strain Curve......Page 112 Displacement-based Stress–Strain Curve......Page 115 Tensile Response of Materials......Page 116 Uncertainty in Stress......Page 121 Uncertainty in Elastic Modulus (Monte Carlo Simulations)......Page 122 Equipment and Supplies Needed......Page 123 Required LabVIEW Program (VI)......Page 124 Experimental Task......Page 125 Issues to be Discussed in the Lab Report......Page 127 Principal Equipment Requirements and Sourcing......Page 128 Equipment and Resources Needed......Page 129 Problem Statement......Page 130 Experimental Task......Page 131 Issues to be Discussed in the Lab Report......Page 132 Principal Equipment Requirements and Sourcing......Page 133 Thin-walled Pressure Vessels......Page 135 Introduction......Page 136 Theory of Strain Rosette......Page 137 Stress–Strain Relationships......Page 139 Theory of Thin-walled Pressure Vessel......Page 141 Uncertainty Calculations (From Hoop Stress)......Page 149 Experimental Task......Page 151 Required LabVIEW Program (VI)......Page 152 Experimental Task......Page 153 Principal Equipment Requirements and Sourcing......Page 154 Strength of Adhesive Joints......Page 155 Introduction......Page 156 Experimental Tasks......Page 159 Issues to be Discussed in the Lab Report......Page 161 Creep Behavior of Metals......Page 163 Mechanism of Creep......Page 164 Equipment Needed......Page 168 Experimental Task......Page 169 Principal Equipment Requirements and Sourcing......Page 172 Charpy Impact Testing......Page 173 Wind Resistance and Frictional Losses......Page 174 Monitoring of Forces During Impact......Page 176 Determination of F_impact......Page 178 Problem Statement......Page 180 Experimental Procedure......Page 182 Equipment Requirements and Sourcing......Page 184 Flexural Loading, Beam Deflections, and Stress Concentration......Page 185 Stress in a Beam......Page 186 Simply Supported Beam......Page 187 Simply Supported Beam with Two Forces Acting at Equidistant from End Supports......Page 189 Stress Concentration......Page 190 Beam Deflections......Page 191 Four-Point Bending Apparatus with Instrumented Beam......Page 197 Typical Wiring for Strain Gages and Load Cell......Page 199 Required LabVIEW Program (VI)......Page 200 Equipment Requirements and Sourcing......Page 201 Wave Propagation in Elastic Solids and Dynamic Testing of Materials......Page 203 Basic Concepts of Wave Propagation......Page 204 1D Stress Wave Propagation in a Slender Rod......Page 207 Wave Reflection at a Free-end......Page 209 Measurement of Stress Wave Duration and Amplitude......Page 210 Wave Transfer Through a Boundary Between Two Similar Rods......Page 211 Dynamic Stress–Strain Response of Materials......Page 216 Experimental Task......Page 221 Equipment Requirements and Sourcing......Page 223 Authors' Biographies......Page 225