关键词: 双曲型方程, 能量估计法, 下界估计

Abstract: We considered the lower bound for the lifespan of the solutions to a class of fourthorder nonlinear coupled hyperbolic systems. 
By constructing the appropriate control function, using the energy estimate method and Sobolev embedding theorem, we  gave the firstorder differential inequality satisfied by the control function, and gave the estimate of the lower bound for the lifespan of the solution of the problem by analyzing  the properties of differential inequalities.

Key words:  , hyperbolic equation, energy estimate method, estimate of lower bound