Accurate contour plotting using 6-node triangular elements in 2D

We present an accurate contour plotting algorithm using 6-node triangular elements. The algorithm traces contours as accurately as the analysis results obtained in FEA. The quadratic nature of the interpolation is analyzed in details and fast algorithms are developed to accurately interpolate the function representing the various conic sections in 2D. Data structures and algorithm for joining the contour segments derived on individual elements are presented. Numerical results are presented and comparisons are made with contours using 3-node triangular elements.