轴向运动黏弹性梁：积分一偏微分 非线性组合参数共振

通过对SEL-351A的零（负）序方向元件分别在接地方向、相间故障方向及三相短路故障方向的理论分析,结合电测试数据阐述了对SEL-351A继电器方向元件的认识。

The Understanding of direction elements of SEL-351A relays

Steady-state response of nonlinear axially beams is investigated in summation parametric res­onance. The material time derivative is used in the viscoelastic constitutive relation. The transverse mo­tion can be governed a nonlinear integro-partial-differential equation. The summation parametric reso­nance may occur when the axial speed variation frequency approaches the sum of any two natural fre­quencies. The asymptotic analysis is performed to determine steady-state responses. The differential quadrature scheme is developed to solve numerically the governing equation and verify results via as­ymptotic analysis. Numerical examples show the effects of correlative parameter on steady-state re­sponse. The numerical results validate the analytical results.