THE PRINCIPLE OF VIRTUAL WORK AND THE THIRD ORDER WAVE FOR CONTINUA WITH SECOND ORDER CONSTITUTIVE EQUATIONS

摘要

A generalized form of the principle of virtual work where the virtual work is a time integral of virtual power is obtained. The corresponding Euler-Lagrange equation includes the divergence of the Lie derivative of stress. The equation of motion on the stress rate field is one of the results of this paper. A generalization of the acoustic tensor is obtained for a third-order wave. The generalized acoustic tensor seems the most important result of this paper. It can also be found by investigating an acceleration wave