دانلود رایگان مقاله تحلیل حالات شکست انفجار نهایی در ورقه های فلزی فیبر

Abstract

Finite element modelling has been applied to simulate various failure modes in fibre metal laminate (FML) panels under localized high intensity blast loading. A relatively simple material model, based on continuum damage mechanics, has been proposed to describe the constitutive response of the composite material in the FMLs. Simulations of the blast response of FMLs with various stacking configurations has been carried out, capturing both perforation and non-perforation failure modes. Blast loading was modelled by a pressure function applied on the front face of the FML panel. The definition of the pressure function accounts for both the temporal as well as the spatial distribution of the blast. The capability of the models has been assessed by comparing the predictions associated with both low and high intensity blast cases with published experimental data. Good qualitative and quantitative agreement has been observed for lay-ups with similar proportions of aluminium and composite. It is believed that the models can be employed for use in parametric studies that would facilitate the adoption of FMLs in wider engineering design.

5. Conclusions

A numerical study on the blast response of FML panels has been presented. Finite element modelling of panels based on various stacking configurations has been carried out using the commercial software package Abaqus/Explicit. Here, a relatively simple continuum mechanics-based material model for the composite has been proposed and implemented into the main program through a user-defined subroutine. The model incorporates 3D constitutive behaviour, a damage evolution law and rate-dependency of the composite material. Comparisons of the numerical predictions with published experimental data has shown that the model is capable of capturing the observed deformation and damage modes with a good degree of accuracy. A systematic assessment of the predicted modes of deformation and damage for a variety of the loading cases has been carried out. It has shown that the predictive capability of the models reduces for panels with a larger number of constituent layers. One of the reasons behind this is the conservative criterion for element deletion in composite, resulting in over-estimation of the failure of composite layers, which in turn affects the deformation and damage in the adjacent aluminium and cohesive layers. In simpler loading cases, however, the predictions from the models are entirely reasonable and accurate. For such cases, the models can be used in their current form to undertake parametric studies that consider varieties of FMLs made with various constituent materials, provided that the choice of the material properties, specifically, the damage-related parameters, is reasonable, so that the blast resistance would not be over-estimated.