Abstract
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. © 2011 WIT Press.