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.
Author(s): Ghatu Subhash, Shannon Ridgeway
Series: Synthesis Sem Lectures on Experimental Mechanics
Year: 0
Language: English
Pages: 226
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
