Calculate the gain in bending efficiency, \(\psi_{B}^{e}\), when a solid is formed into small, thin-walled tubes of radius \(r\) and wall thickness \(t\) that are then assembled and bonded into a large array. Let the solid of which the tubes are made have modulus \(E_{s}\) and density \(ho_{s}\). Express the result in terms of \(r\) and \(t\).