Non-scalar approach to simulate the mechanical degradation process in fibre-reinforced-polymers (FRPs)

A non-scalar formulation of the mechanical degradation process in FRPs is proposed. The approach bases on understanding the complex degradation process of a dynamically loaded FRP as a curve in a K-dimensional space. Each dimension of this space represents one type of observable physical damage (e.g., transverse crack formation and delamination) or one empiric damage parameter (e.g., damage according to Miner's rule). All points on the curve - or all stages of the damage process - are described unambiguously by a K-dimensional array D. Each component of D ascends monotonically with the applied load. By choosing summable parameters for the components of D and by breaking down the load into incremental load changes DeltaL this non-scalar approach enables the damage growth with an applied load to be described in terms of numerical methods for evaluation and simulation. Furthermore, the proposed description allows to utilise a physically based damage accumulation hypothesis for dynamically loaded FRPs and to account for the interactions between different types of damage.