The Cauchy problem for a coupled evolution equations with nonlinear weakly damping on the whole space Rnis considered.A blow up result of weak solution with arbitrarily positive initial energy is obtained.And it generalized some previous results about this system.To overcome the lack of the Poincare inequality in Rn,the finite speed of propagation property of solutions be used here to estimate some norm in relation to solution,after the solution be decomposed into linear...
