Rehabilitation of Cracked Aluminum Connections with GFRP Composites for Fatigue Stresses

The original design of existing aluminum overhead sign structures (OSS) did not consider fatigue as a limit state. Cracks propagate in the welds of the connection between the main chord and branches of OSS due to fatigue stresses caused by wind-induced vibration, which occasionally lead to complete fracture of the welds. In this paper, a rehabilitation method for cracked aluminum welded connections using glass fiber-reinforced Polymer (GFRP) composites is investigated for its effectiveness under fatigue stresses. Results of constant amplitude fatigue tests for 3 types of aluminum connections from actual OSS are given: 1) connections with no known cracks; 2) cracked connections rehabilitated with GFRP composites; and 3) connections with 90% of the weld removed and subsequently repaired with GFRP composites. The fatigue limits of the 3 connection types are established for 4 stress ranges including the constant amplitude fatigue limit threshold. The rehabilitated connections from OSS exceeded the fatigue limit of the aluminum welded connections with no known cracks. The repaired connections with 90% of the weld removed satisfied the constant amplitude fatigue limit threshold. A cumulative damage index is established leading to a fatigue reduction factor for rehabilitation design of cracked aluminum connections using the GFRP composites.

  • Availability:
  • Supplemental Notes:
    • Abstract reprinted with permission from ASCE
  • Authors:
    • Nadauld, Justin D
    • Pantelides, Chris P
  • Publication Date: 2007-5

Language

  • English

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 01051338
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jun 10 2007 1:13PM