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原文传递 Pendulum Impact Testing of an Impact-Breakaway, Wind-Resistant Base Connection for Multi-Post Ground Signs.

题名：	Pendulum Impact Testing of an Impact-Breakaway, Wind-Resistant Base Connection for Multi-Post Ground Signs.
关键词：	connection；pendulum；resistant；testin；impact；sting；post；multi；round；away
摘要：	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.
报告类型：	科技报告