WIT Press

Constitutive Formulation Of Strain-rate Sensitive Deformation In Orthotropic Composites


Free (open access)





Page Range

397 - 408




331 kb

Paper DOI



WIT Press


K. Micallef, A. Soleiman-Fallah, P. T. Curtis, D. J. Pope & L. A. Louca


The aim of the current study is to develop a constitutive model which captures the full orthotropic behaviour of a laminated composite by employing 9 material parameters and also taking into account strain-rate sensitivity to loading. The formulation is an extension of the work by Ogihara and Reifsnider (DOI: 10.1023/A:1016069220255), whose model considers 4 parameters, and with the inclusion of strain-rate effect considerations using the method employed by Thiruppukuzhi and Sun (DOI: 10.1016/S0266-3538(00)00133-0). A plastic potential function which can describe plasticity in all directions, including fibre plasticity, is chosen and using an associated flow rule, the plastic strain-rate components are derived. The plastic compliance matrix is assembled, using a rate-dependent visco-plastic modulus. The elastic compliance matrix is combined with its plastic counterpart to give a rate-form constitutive law. It is found that the proposed model accounts for strain-rate dependence and by correct choice of model parameters, the model can also be used for various composite architectures, including woven and uni-directional architectures. Keywords: composites, orthotropic, constitutive modelling, strain-rate effects 1 Introduction The formulation of a comprehensive constitutive model is imperative for the proper understanding of a material’s behaviour under different loading conditions. This includes fibre-reinforced laminated polymeric composites. For efficient use of composite materials under extreme loading, it is necessary to


composites, orthotropic, constitutive modelling, strain-rate effects