Pendulum impact testing of an impact-breakaway, windresistant base connection for multi-post ground signs.

Details

• Creators:
  Consolazio, Gary R. ; Bui, Long H. ; Walters, Robert A.
• Corporate Creators:
  University of Florida. Dept. of Civil and Coastal Engineering
• Corporate Contributors:
  Florida. Dept. of Transportation. Research Management Center
• Subject/TRT Terms:
  • Signs
  • Structural supports
  • Impact
  • Crash tests
  • Crashes
  • Breakaway supports
  • Finite element method
  • Dynamic structural analysis
  • Static structural analysis
  • Friction
  More +
• Publication/ Report Number:
  2012/92174
• Resource Type:
  Tech Report
• Geographical Coverage:
  Florida
• Edition:
  Final report; Feb. 2011-May 2012.
• Corporate Publisher:
  University of Florida. Department of Civil and Coastal Engineering
• Abstract:
  Roadside signs play an important role in traffic control systems and must be placed adjacent to roadways. If they are not designed, ; fabricated, and installed properly, ground signs may pose potential hazards to vehicle passengers in the event of a vehicular collision with a ; sign structure. Ground signs must be strong enough to resist hurricane wind loading and self-weight, and yet sufficiently frangible to avoid ; extreme vehicular deceleration on impact. Such deceleration can cause abrupt occupant deceleration or excessive vehicle compartment ; deformation, either of which can cause serious or fatal occupant injuries. Consequently, sign structures located adjacent to roadways are ; generally designed to break away or yield under vehicle impact loading. Presently, a breakaway slip-base connection system is used in ; Florida. The breakaway mechanism of this system, however, depends on specific pretension levels in the bolts of the connection. ; Therefore, the performance of this system is undesirably sensitive to the level of bolt-torque that is imposed during installation and ; maintenance. ; In this study, a new breakaway sign post base connection, the ‘shear-controlled moment collar’, was developed and subjected to ; static and dynamic testing. The new connection system is capable of resisting code-specified equivalent static hurricane wind loads, but ; also breaks away under low energy impact (vehicular) loads. Development of the connection involved several phases: conceptual ; development using nonlinear dynamic finite element analysis; structural design; validation of wind load capacity using static experimental ; testing; and validation of breakaway performance using pendulum impact testing. Experimental determination of friction coefficients for ; Teflon sheets, used in conjunction with structural steel, was also carried out. In addition, a permanent high-energy impact pendulum test ; facility was designed and constructed as part of this research and used to conduct dynamic impact tests on the newly developed breakaway ; connection.
  More +
• Format:
  PDF
• Funding:
  BDK75 977-40
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/24703/dot_24703_DS1.pdf
• File Type:
  [PDF - 26.34 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:b7d6151f711b03bb4f82e8094f912990150066a3f2ab320d1ffd82642fbdc9ad