Performance of W-Beam Splices

Structural failure of post-and-beam W-beam guardrails during impact sometimes is due to the rupture of the W-beam rail where two sections are spliced together with bolts. Summarized is a study of the mechanics of failure of the splice connection. The causes of rupture are identified, and a design alternative is formulated that will reduce the likelihood of rupture of the splice connection. The tensile forces in the W-beam rail and the mode of deformation of the splice connection during impact were critical factors considered in the study. The results of full-scale crash tests, laboratory tests, and finite element analysis indicate that relocating splices to midspan locations would greatly reduce the chance of observing a rupture of the guardrail in full-scale crash tests and in real-world collisions.