Influence of fiber length on the tensile behavior of fiber metal laminates with discontinuous reinforcement

In this paper, the influence of fiber length on the tensile behavior of fiber metal laminate, which is fabricated with unidirectionally arrayed chopped strand plies and aluminum sheets and named as unidirectionally arrayed chopped strand/aluminum laminate, was investigated based on finite element analysis and experiment. The unidirectionally arrayed chopped strand ply is made by introducing slits into carbon fiber reinforced plastic prepreg where continuous fibers are arrayed unidirectionally. The fiber length is one of the most fundamental factors in tailoring the unidirectionally arrayed chopped strand/aluminum laminate to achieve the desired mechanic behaviors for specific applications. With longer fiber length, the mechanical behaviors of the bulk laminate should be more favorable, while the formability would be better with short fiber. Two-dimensional finite element models, with intra-laminar cohesive zone elements inserted into the slits of unidirectionally arrayed chopped strand plies and inter-laminar cohesive zone elements inserted into the all interfaces of unidirectionally arrayed chopped strand/aluminum laminate, respectively, were developed for the analysis of unidirectionally arrayed chopped strand/aluminum laminates with different fiber lengths under tension. Typical numerical results were validated by experimental results, which confirm that the tensile behaviors of the unidirectionally arrayed chopped strand/aluminum laminates with various different fiber lengths can be well predicted by present numerical modeling method.