A Study of Negative Poisson's Ratio in Randomly Oriented Quasi-Isotropic Composite Laminates

Abstract

In isotropic materials, it is known that values of Poisson's ratio larger than one half are thermodynamically inadmissible, for such values would lead to negative strain energy under certain loads. Although a negative Poisson's ratio is not forbidden by thermodynamics, it is rare in crystalline solids. With the development of modem fiber reinforced composite materials, the effective Poisson's ratio of laminated fiber reinforced composites shows a peculiar behavior as it becomes larger than one half or less than zero. In this article, a study of negative in-plane Poisson's ratio for a general class of randomly-oriented composite laminates is presented. A simple random statistical analysis has been presented. It is demonstrated that composite laminates with negative in-plane Poisson's ratio could be achieved by using the specific values of independent elastic constants E1, E2, G12, and v12 in each lamina. Also, the influence of the lamina material properties to the negative in-plane Poisson's ratio of the composite laminates is presented. The results from this statistical analysis provide a set of general guidelines for designing composite laminates with a special character-the negative in-plane Poisson's ratio.

Modelling the influence of the orientation and fibre reinforcement on the Negative Poisson's ratio in composite laminates

“…This is due to the anisotropy mentioned earlier. It is interesting to note that the only auxetic behaviour designed into glass/epoxy laminates was in [13,19]. The work performed here has shown that the glass/epoxy laminates based on a [±θ 2 ] s configuration always have a positive ν 13 and ν 23 due to the lack of anisotropy in the prepreg material.…”

An ultrasound investigation into the morphology of the human abdominal wall uncovers complex deformation patterns during contraction

“…Composite laminate structures can display negative Poisson's ratios (Tsai and Hahn 1980), the more anisotropic the plies, the more readily (Yeh et al 1999) negative Poisson's ratios are observed. The abdominal wall is composed of three sheet-like muscles and their corresponding aponeuroses overlying each other, each with what has been anecdotally described as loose connective tissue intervening (Bendavid and Howarth 2000).…”

Three Decades of Auxetics Research − Materials with Negative Poisson's Ratio: A Review

“…Ply orientations for generating maximum negative Poisson's ratio in a composite laminate are close to 70 /20 . [89] Yeh et al [90] demonstrated that by using specific values of elastic constants E 1 , E 2 , G 12 , and n 12 in each lamina; a composite laminate with negative in-plane Poisson's ratio can be generated. It is important that the ply material should be anisotropic for generating through thickness negative Poisson's ratios in composite laminates.…”