Interesting paper JLNJ, thank you. Solving Equation 1 with the 4000 lbs and 4 mph given in the guardrail's crash rating, as well as the approximation given in the paper for δc, gives an impact force of 2650 lbs with 0 in. of barrier deflection, 2402 lbs with 1 in. deflection, and so on. Is this...
chucklesNOLA: thanks for the link to that NCHRP report. This is the guard rail that's being used and the cross section looks comparable to the W beam in the table. It will be going into a parking garage so high speeds aren't really a design issue.
For clarification, the guard rail is rated for 4,000 lbs at 4 mph but the drawings for the project cannot be approved unless the rail is shown to withstand a 6,000 lb point load. The manufacturer's information doesn't provide the rail's rating as a static load, which is where my issue lies.
I'm looking to verify that the dynamic load for a guard rail will withstand a 6000 lb point load. The rail is 10 gauge galvanized steel and the manufacturer's crash rating is 4000 lbs at 4 mph.
I know that KE = 1/2 x m x v^2 and
F = m x a
but calculating kinetic energy doesn't seem to help...
