Determination of Key Mechanical Properties for Simulating Delamination Damage in Impacted Bonded Joints of Composites

Abstract

Non-linear dynamic FE simulations of impact event and ensuing progressive delamination and disbond failure, were performed for lap joints of composites (woven fabric reinforced phenolic) having four different overlap widths. The joints were impacted transversely using a hemispherical impactor with different velocities in the low velocity impact range. These simulations were used to explain the experimentally observed dependence of damage on overlap width and impact velocity using the concept of characteristic overlap width. The experimental observations of damage mechanisms were carried out using a combination of techniques including, through transmission photography, ultrasonic c-scan and x-ray micro tomography (XMT). Progressive damage simulations like the one described in this study require significant input material properties to run and generally little details are provided in literature about the experimental procedure to determine these values. Thus in this paper, determination of key material parameters for progressive delamination modelling in single lap joints of woven glass fabric reinforced phenolic composites, has been discussed thoroughly.