An experiment-based method for parameter identification of a reduced multiscale parametric viscoelastic model of a laminated composite beam

Abstract

Usual CAE tools simulate the behavior of composite parts from models considering the structures as being homogenized. Such approach reveals itself not to be effective when the engineer aims at determining the number of plies and the material characteristics of each ply to aim a specific dynamic behavior. To reply to this problem, we developed a multi-scale model that explicitly integrates the different design parameters of the composite structure being considered at different scales: the number of plies, the orthotropic law of each ply and the characteristics of each interface between the plies made by the matrix. This paper is detailing the method that we developed to lead to our multi-scale and parametric model. This method is coupled to an experimental approach that allows specific variables named fractional variables to be identified. These variables add to the detailed representation of the dynamic capacities of the laminated composite beams that led our study. In the case of our composite beams, the effect of damping due to the ply-interface behavior is significant, and consequently we dealt with the viscoelastic response of the laminated composite beam under dynamic load. As a result, the strategy of simulation based on our reduced, viscoelastic and multi-scale beam model is presented: solutions with low computational resources may be obtained. Keywords

Support for Decision Making in Design of Composite Laminated Structures. Part 1: Parametric Knowledge Model

“…On the other hand, the interfaces between plies are considered isotropic, so the stiffness is given by eqs. ( 9) and (10). 13…”

“…We use a separated approach that leads us to consider the density ρ m only at the level of the interfaces and the density ρ f at the level of the plies; we do not use a mixture law, some experiments have demonstrated that this is sufficient to represent the dynamic behavior as shown in Fig. 7 Distribution of density [10]. Parameters holding the constitutive law of the plies p 5…”

“…In previous work, a dynamic experiment showed that the behavior of the laminated structure is viscoelastic because the response is lagging the force excitation, this effect is shown in Fig. 10 Justification of viscoelastic response [10]. Therefore, we decided to model this behavior although it is not commonly represented in usual simulation models, so we proposed after analyzing the displacement field to consider both the phenomena of creeping and stress relaxation of the laminated structure.…”

“…This process is described in the paper published by Fontecha Dulcey and al. [10] in the journal of Applied Composite Materials..…”

“…Additionally, the reduced model is parametric within predefined intervals; the displacement field is a function of critical design parameters: the number of layers, the number of plies, the fiber angle, the fiber volume fraction and the viscoelastic nature of the interfaces. In our paper titled Support for Decision Making in Design of Composite Laminated Structures; Part 2: Reduced Parametric Model-Based Optimization [10], published by the journal of Applied Composite Materials, we present a way to support decision making during laminated composite structure design using our Parametric Knowledge Model (PKM). Two simple cases are presented to illustrate the flexibility of the approach when representing the behavior of composite structures: one involving a static load and the other using a force oscillating over time.…”