in this paper, the behavior of free vibrations and buckling of the sandwich panel with a flexible core was investigated using a new improved ‎high-order sandwich panel theory. in this theory, equations of motion were formulated based on shear stresses in the core. first-order shear deformation theory was ‎applied for the procedures. in this theory, for the first time, incompatibility problem of...

In this paper, the transient response of a viscoelastic annular plate which has time-dependent properties is determined mathematically under dynamic transverse load. The axisymmetric conditions are considered in the problem. The viscoelastic properties obey the standard linear solid model in shear and the bulk behavior in elastic. The equations of motion are extracted using Hamilton’s principle...

When one of the dimensions of a structural member is not clearly larger than the two orthogonal ones, engineers are usually compelled to simulate it with refined meshes of shell or solid finite elements that typically impose a large computational burden. The alternative use of classical beam theories, either based on Euler-Bernoulli or Timoshenko’s assumptions, will in general not accurately ca...

In this article, a new higher order shear deformation theory based on trigonometric shear deformation theory is developed. In order to consider the size effects, the nonlocal elasticity theory is used. An analytical method is adopted to solve the governing equations for static analysis of simply supported nanoplates. In the present theory, the transverse shear stresses satisfy the traction free...

A Timoshenko beam theory for layered orthotropic beams is presented. The theory consists of a novel combination of three key components: average displacement and rotation variables that provide the kinematic description of the beam, stress and strain moments used to represent the average stress and strain state in the beam, and the use of exact axially-invariant plane stress solutions to calibr...

Current active vibration suppression systems usually consist of piezoelectric extension actuators bonded to the surface or embedded within the structure. The use of piezoelectric shear actuators/sensors has been proposed as an alternative, where the electric field is applied perpendicular to the direction of polarization to cause shear deformation of the material. We present an exact analysis a...

The recently developed drift spectrum is extended to buildings that do not deform laterally like pure shear beams. Similarly to Iwan’s drift spectrum, the proposed generalized interstory drift spectrum uses a continuous linear-elastic model to obtain estimates of interstory drift demands in buildings. However, the generalized interstory drift spectrum is based on a continuous model that consist...

The response to cyclic deformation has been studied for Cu/Cu multilayer material consisting of columns of closely spaced, parallel nanotwins. The fatigue life under stress-controlled cycling is greatly improved over that of coarse-grained Cu. Nanotwinning provides significant strengthening, which is unchanged by fatigue or severe compression. Observations by focused ion beam microscopy showed ...