搭接连接系统的非线性振动分析

摘要

Nonlinear vibration characteristic of Lap-type jointed structure system is investigated through an adjusted Iwan hysteretic model. The steady dynamics response and transition response are obtained by first-order and higher harmonic balance method (HBM). The approximate solutions are compared with numerical integration solution. It shows that the approximate HBM solution matches well with numerical solution; system shows a soft stiffness nonlinear but no jumping in frequency response curve. The equivalent linear system normal frequency decreases with vibration amplitude during transition response and including high order even harmonic.%针对航空航天结构中典型的搭接连接系统，基于改进的Iwan迟滞非线性模型研究系统的非线性振动特性。采用谐波平衡法对系统稳态阶段响应求解，获得了系统的一阶谐波和三阶谐波近似解，并和数值积分解进行对比。分别研究了系统在谐波激励下的稳态解和瞬态解。结果表明，谐波平衡法获得的近似解与数值解吻合较好；谐波激励下系统的稳态响应具有软化非线性但不生跳跃的特点；瞬态响应中，等效系统固有频率随幅值降低而降低，响应信号中包含偶数倍高阶谐波分量。