SEM Road Barrier & Seat Shock Tests & Test Dummy Waving

A series of crash test were run on the SEM (Solid Ejection Material) shock isolator technology in 11/04 and 11/05 at the Texas Transportation Institute. The purpose of the test effort was to see if the crash performance of stock railcar seats could be improved with SEM shock modifications. The SEM technology was also employed in the impact barrier to deliver a spec crash pulse to the Bogie test vehicle. In both energy absorption applications the SEM technology performed very well. The seats were allowed to have a controlled displacement and the SEM impact barrier just about aced the desired triangular crash pulse.

While better crash performance could be had by adding some form of padding to the seat back, the SEM seat shocks did reduce some of the loading after the initial load spike. If SEM seat shocks were employed in a horizontal impact event, then the ideal design would be a stiffer seat structure, with back padding and the SEM shocks would be designed to deliver an ideal restraint load performance with the desired displacement. Some current seat designs have some of these design parameters, such as aircraft seats, but current aircraft seat designs have no controlled travel, or in other words, no form of horizontal shock isolation. Another ideal application for SEM seat shocks would be vertical load seat shocks, to reduce the impact and blast injuries that military personnel experience in emergency helicopter landings and in ground vehicles that hit mines or IEDs.

One last thought that we try to touch on in the video, and that is, SEM shocks can literally stop a train. If you look at the current barrier design, in this video clip, the I-beam that supports the SEM shock housings is much like a steel rail. So why not install such systems right into the rails, at track termination points, in the form of bumping posts; or put SEM shocks into the rails to act as "runaway" tracks, to stop trains that loose their brakes? The restraint load performance for this particular barrier design, which was used in this High Speed Rail-IDEA study, topped out at 35,600 lbsf but that could be easily be scaled up to 350,000 lbsf for a rail braking system.

Again the SEM technology is very diverse and we are currently pursuing interested parties to get select application markets launched.

Category:

Autos & Vehicles

Tags:

• Road
• Barrier
• Vehicle
• Impact
• Absorber
• Crash
• Dummies
• Seat
• Shocks
• New
• Technology

[SEMShocks]

I know what you mean. But sometime I believe management thinks we Engineers are the test dummies. I still like that clip of the 2nd test run where the dummy (not Engineer) looks like he's waving goodbye.

[stopglobalswarming]

I understand the science being tested here, but for some reason dummy tests are just funny.