Normal, high and ultra-high modulus carbon fiber-reinforced polymer laminates for bonded and un-bonded strengthening of steel beams

摘要: Abstract This paper studies the elastic behavior of steel beams strengthened with normal, high and ultra-high modulus CFRP laminates using bonded un-bonded systems. The retrofitted provides useful information for design fatigue strengthening A total seven including one control unstrengthened beam six were tested statically until failure in a simply supported four-point bending set-up. by normal (NM), (HM) (UHM) carbon fiber-reinforced polymer (CFRP) nominal Young’s moduli, ranging from 165 to 440 GPa. Each type laminate was attached reinforcement (BR) (UR) There is no direct comparison between BR UR systems literature. main goal provide better understating about stress distribution along bottom flange when are used strengthening. All specimens failed due lateral-torsional buckling (LTB). effect different methods on capacity also studied. Experimental results have shown that UHM could increase stiffness composite section so profile has yielded prior larger efficacy then achieved.