Two-Dimensional Stress State

This lecture covers the concept of two-dimensional stress states, including the principle of superposition, sensor membranes, and the relative variation of volume. It delves into energy density, constraints, and the stiffness matrix. The instructor explains the analysis of stress states for reference axes coinciding with principal axes, as well as for axes different from the main axes. Practical examples, such as a square plate under linear load, are used to illustrate the theoretical concepts. The lecture concludes with the construction of Mohr circles and the calculation of normal and tangential stresses in oblique sections.