Figure 51. The breakaway region calculated with perpendicular erosion in this bogie impact simulation looks more realistic than that calculated without perpendicular erosion. Diagrams A and B.

1. With perpendicular erosion. This first diagram shows a rectangular column. The column is sheeted on either side by what would be neoprene, approximately fifteen rows up from the bottom of the structure. The structure is broken down into rows and columns of small squares. The top half of the structure is colored a dull aqua with the exception of a small strip, seven rows wide, which is, colored a dull blue. A dark blue section exists near the bottom of the structure, six rows of it resting above the neoprene barrier and six rows resting below. At the mouth of the neoprene barrier, a good chunk of squares is missing. Nine squares total are missing from three columns, two columns in while the first five squares are missing in the row that rests on the neoprene line.

2. Damage fringes without perpendicular erosion. This diagram shows a rectangular column. The column is void of color to accentuate the areas of damage. The column is sheeted on either side by what would be neoprene, approximately fifteen rows up from the bottom of the structure. The top half of the structure is tilted to the right, a five squares of a row missing where the neoprene line ends. A column of eight squares, three columns in is colored a dark red, the ninth square colored a pale green. The column next to the latter has its first square colored a dark red and the next colored a pale green. These columns exist below the gap formed by the tilt of the upper half. In the row of squares above the gap, four of the eight squares is colored a dark red, where the next row up has three of the eight colored a dark blue.

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FHWA-HRT-05-096