Durability Assessment of Combined Environmental Exposure and Bending

Abstract

Synopsis: Although fiber reinforced polymer (FRP) composites are increasingly being used in civil infrastructure applications, there is still a lack of well documented data and understanding regarding their long-term performance especially under combined exposure to environmental conditions and sustained load. This paper presents the results of an investigation into synergistic effects of hygrothermal exposure and sustained strain on pultruded E-glass/vinylester composites. It is seen that effects of increasing strain levels can be significant and can lead to changes in damage mechanisms, especially in conjunction with moisture uptake. High strains in combination with moderate to elevated temperatures resulted in substantially more catastrophic failure than elevated temperatures in combination with lower strains. These effects were noted in tension and short-beam-shear modes, and overall deterioration was corroborated by moisture uptake, Dynamic Mechanical Thermal Analysis (DMTA) and Fourier Transform Infrared Spectroscopy (FTIR) investigations.