Finite element for viscoelastic composite plate bending using efficient higher-order displacement field

Time-dependent responses of composite plate are investigated based on efficient higherorder plate theory. The constitutive equation of linear viscoelastic materials, expressed as a Boltzmann superposition integral equation, is simplified by the convolution theorem of Laplace transformation. Hence, the computational resource can be saved significantly. A triangular bending element based on an efficient higher-order plate theory is applied to the viscoelastic composite plate. To pass the shear patch tests in all configurations, a modified shape function derived by Specht has been employed. To demonstrate the element and compare with other elastic and viscoelastic theories, the static bending problem under sinusoidal loading is considered, the material properties of graphite/epoxy GY70/339 are used to describe the viscoelastic responses like creep strain and relaxation stress. The present research provides an accurate and efficient tool for time-dependent problem of laminates.