AN ENERGETIC FORMULATION FOR THE LINEAR VISCOELASTIC PROBLEM .1. THEORETICAL RESULTS AND FIRST CALCULATIONS

An extremal principle is formulated for the linear viscoelastic proble m with general viscous kernel. This is an extension of the classical t otal potential energy principle of the linear elasticity. Then a discr etized formulation in space and time is shown for frame structures, us ing finite element technique. Several numerical examples, for two diff erent kinds of viscoelastic materials, testify the accuracy and reliab ility of the proposed method. The matrix conditioning indexes obtained are compared with those achieved by applying the least square method.