Non-classical mechanical behavior of an elastic membrane with an independent Gaussian bending rigidity

Abstract

The present work considers the mechanical behavior of a non-classical elastic membrane with two independent bending rigidities. Our interest focuses on the case when the ratio of the Gaussian bending rigidity to the common flexural rigidity falls within the non-classical range, which cannot be covered by a classical elastic plate with an admissible positive Poisson ratio. Our results for a rectangular elastic membrane with two opposite free edges show that its deflection under a uniform transverse pressure could be considerably (even more than twice) larger than a classical elastic plate under otherwise identical conditions, while its lowest fundamental frequency and critical buckling force could be considerably (even more than 50%) lower than a classical elastic plate under otherwise identical conditions. These unexpected results suggest that, unlike classical elastic plates whose actual mechanical behavior are often insensitive to the value of the admissible positive Poisson ratio, actual mechanical behavior of a non-classical elastic membrane with two independent bending rigidities could be very sensitive to the exact values of the two independent bending rigidities. Therefore, the exact value of the Gaussian bending rigidity could be crucial for such non-classical elastic membranes. Only knowing the values of the flexural rigidity and Poisson ratio is insufficient for accurate prediction of mechanical modeling of such non-classical elastic membranes with two independent bending rigidities (such as some biomembranes and atom-thick monolayer membranes).