Reliability Analysis of Carbon Fiber Reinforced Polymer (CFRP) Strengthened Steel Beams
This dissertation was conducted to investigate the behavior of bonded joints between steel and carbon fiber reinforced polymers (CFRP) with an emphasis on understanding the role of the adhesive mechanical properties and the surface preparation techniques used to produce the joints. Reliability analysis of adhesively bonded CFRP-to-steel double-lap shear (DLS) joints with thin outer adherends was performed first, to study the bond behavior when dominated by adhesive shear stresses. A comprehensive experimental database of the DLS joints was compiled to study the model uncertainty for the widely adopted Hart-Smith model. Reliability methods, namely, Monte Carlo Simulation (MCS) and First-Order Reliability Method (FORM) have been performed to calculate the resistance factors of DLS joints for different design scenarios. The sensitivity study quantifies the relative contribution of each design variable to the reliability index. Thereafter, an experimental database for CFRP strengthened steel beams that fail by debonding was compiled to determine the modeling uncertainty of the existing design approach recommended by the design guidelines. MCS has been carried out to calculate the resistance factors and the sensitivity study demonstrates the effects of each design variable on the reliability index. Implications of using the partial safety factors recommended by current design guidelines have also been studied.