A NEW MODEL FOR HIGH-STRAIN RATE IMPACT IN BONDED/CO-CURED COMPOSITES

Sandeep Chellapilla, Matthew Streby, Som R. Soni, Ronald L. Hinrichsen, Phillip Geubelle

ABSTRACT

We report on theoretical and experimental modeling of high strain-rate effects of bonded/co-cured composites. Experimental testing of DCB specimens under Mode I failure conditions at various strain rates, is also reported. Plots of load vs. stroke at various rates are used to compute the mode I energy release rate GI. A proprietary computer program has been developed to aid in the analysis of interlaminar failure in composites, and to predict fracture parameters, thus providing a useful reduction module. An evaluation of Dyna3D2000 joint modeling options, and simulation of Mode I failure is presented. A Cohesive/Volumetric Finite Element (CVFE) is being investigated as a modeling innovation for use with Dyna3D2000. A 2D-CVFE code specially designed for the simulation of double cantilever beam (DCB) experiments has been developed and implemented wherein cohesive elements are placed along the plane of the initial notch are used to model the initiation, dynamic propagation, and possible arrest of the interlaminar crack.