Skip to main content
University
of
Nebraska–Lincoln
Log In
Search
Search
Submit
Close
Midwest Roadside Safety Facility
Menu
Search
Log In
Home
Who We Are
History
Faculty/Staff
Employment
Contact Us
Services
Testing
Finite Element Analysis
Design/Consulting
Pooled Fund
About
Member States
Active Projects
Members Only
Tech Transfer
Newsletters and Featured Research
Research Hub
AFB20 (user/password required)
Pooled Fund Q&A
Q&A Home
Ask a Question
Search Questions
Q&A Reports
Login
Q&A Home
Ask Us A Question
Search Answered Questions
Q&A Reports
Login
Nebraska
MwRSF
Q&A Home
Seach Q&A
View Q&A
View Q&A
Ragged edges in the guardrail slot
Question
State
Description Text
This is a picture from our field review. You can see the spur on this brand new GR just installed. I initially thought it was a rare anomaly. However we noted other locations on new installations a significant distance from this project.
You were saying these ragged edges can cause a focus point for the stress and recommend they be filed smooth. This appears that the slot just was not punched clean. I assume this slot was produced by the manufacturer and I guess if the field crew had to correct them, the manufacturer would be hearing from his client the contractor.
System Performance Evaluation
System Types
Road Closure Gates
Thrie Beam Guardrails
Applications
System Features
Date
October 7, 2014
Previous Views (106) Favorites (0)
Attachment
guardrail slot.jpg
Response
Response
(active)
During the early development of the MGS, we fabricated field slots on site by drilling two holes spaced apart and cutting out the area between with a jig saw. At times, there would be a few rough areas or stress risers where the cuts met up with the radii. During crash testing, we observed some tearing around the slot when the bolt head pulled through the rail slot. I recall that we later required the use of a small die grinder to pass around the slot to remove any leftover burrs and smooth the slot. From this experience, we realized that the fabrication of the slot should not include rough/sharp edges or burrs in order reduce concerns for tears initiating in this region. See page 32 of the attached TRR from 2007. It is preferred that we have clean, smooth slots in the rail and near the bolts.
Date
October 8, 2014
Previous Views (106) Favorites (0)
Some parts of this site work best with JavaScript enabled.