Signal Mast Arm Failure Investigation
Matching Research Agency
|Missouri Department of Transportation (MoDOT)|
|L.R. Dharani, Professor|
University of Missouri- Rolla
Mechanical & Aerospace & Engineering Mechanics
Rolla, MO 65409
|One (1) graduate student|
|The Missouri Department of Transportation (MoDOT) has discovered and documented failures in several cantilever signal mast arms on the Missouri highway system. The objective of this project is to identify the exact cause of failure and to recommend remedial actions for preventing future failures in the existing masts and future designs. In particular the following three distinct tasks are involved: Failure analysis of cracked and uncracked mast assemblies, (2) determination of truck and wind induced loads on the mast arm, and (3) Stress analysis and life prediction.|
|Using a commercial finite element code called ABAQUS stress and the stress intensity factors will be computed assuming a preexisting flaw the size of which would be extrapolated from the failure analysis task. For the existing structures we will establish a range of crack propagation life knowing the minimum size of the flaw that fabricator can detect. This information will be used in determining if retrofit on the existing assemblies is going to be cost effective. A computer code will be written for predicting the initiation life using the strain-life approach. A separate program will be developed for integrating the crack growth rate model.|
- Failure analysis of failed mast arms.
- Dynamic load analysis.
- Fatigue analysis.
|Safety of highway structures|
|Project Start Date:||06/30/2000|
|Project End Date:||06/30/2002|
Relationship to other Research/Projects
|NDT of infrastructure materials|
Technology Transfer Activities
|MoDOT will explore fatigue resistant safe life design for signal mast arms.|
Transportation Research Board Keywords
|Welded structures, fatigue, wind loads and signal mast arms|