This document discusses finite element analysis for 2D problems. It describes common 2D elements like linear triangles, quadratic triangles, linear quadrilaterals, and quadratic quadrilaterals. It explains how shape functions are used to derive element stiffness matrices and calculate displacements, strains, and stresses within each element from the nodal values. Key elements covered include the constant strain triangle (CST), linear strain triangle (LST), linear quadrilateral (Q4), and quadratic quadrilateral (Q8). The document also discusses calculating von Mises stresses and using contour plots to visualize stress results.