Photoelasticity presents the development of photoelasticity. This book discusses the principle of optical equivalence of stressed isotropic bodies. Organized into 29 chapters, this book begins with an overview of the progress in three-dimensional photoelasticity. This text then summarizes the approximate theoretical analysis by the strain-energy technique and derives the basic equations for the evaluation of P and Q by graphical integration. Other chapters consider the importance of stress concentrations in the domain of strength of materials, particularly where fatigue is present. This book discusses a well the various instructive fractures and indicates that the strength of bakelite is determined by the maximum tensile stresses as computed by advanced methods of stress analysis. The final chapter deals with the two fundamental problems in three-dimensional photoplasticity and explains the general stress-optic law under plastic flow without unloading. This book is a valuable resource for designers as well as mechanical and civil engineers.