Figure 119. Bogie impact at 29.5 miles per second for a Grade 1 wood post modeled without rate effects (Grade 1 default saturated pine properties).

5 milliseconds.

This figure shows a computer-generated illustration of a post embedded in a concrete brace using the double flap method. The sleeves can be seen on either side of the post, folded over at the entry point. The majority of the post is colored yellow with only a small section near the top colored red and representing the impact point and another small section colored red representing the breaking area. This latter area is the area in which the post is embedded into the concrete brace. The post has begun to split in the red “breaking area” as the post leans a slight degree to the right. The gap forming runs only a quarter the width of the post.

10 milliseconds.

This figure shows the top half of the post leaning to the right hand side as a gap forms in the red section of the post from the resulting impact. The top half leans at a rough twenty-five degree angle from its original position. The gap itself runs nearly the width of the post, and a fracture has occurred at the impact area.

15 milliseconds.

This figure shows the post leaning to the right at a rough twenty-five degree angle. The gap in the red “breaking area” has widened the top half of the post now appearing severed from the lower half of the post. The break appears to be clean and even.

36 milliseconds.

This figure shows the top half of the post leaning at a rough fifty-degree angle, now completely severed from the lower half and existing well outside the original entry point.

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FHWA-HRT-05-096