|
Abstract The existence of multiple periodic solutions for a class of delayed Duffing-type equations was studied by using generalized Poincaré-Birkhoff fixed point theorem. Firstly, a series of constraints were added to a class of delayed Duffing-type equations f, and a Poincaré mapping was defined. By proving that the mapping was “torsional”, it was concluded that the mapping had at least two fixed points in the region. At last, the conclusion that the delayed Duffing equation f had an infinite number of periodic solutions under the constraints was proved.
|
|
Received: 01 April 2021
|
|
|
|
2021, Vol. 34 
