中文摘要：

跳跃非线性是制约多稳态特性（包括稳态个数、位置、阈值和行程）设计的难点。针对多稳态机构存在的关键稳态特征不可控问题，提出一种基于磁-机耦合效应的新型大行程多稳态机构及其设计方法，即引入空间变化磁场来调整系统局部能量极值点的分布状态，实现多稳态特性的精确设计。基于磁荷理论和伪刚体模型法，考虑结构几何大变形对空间磁场分布的影响，建立考虑位移补偿的多稳态非线性跳跃特性分析模型，分析磁结构参数、磁体数量与布置方式对多稳态特性的影响。基于能量变分原理提出多稳态特性设计的能量判据，揭示稳态与伪稳态之间的关系，得到稳态特征存在的条件。研制一种新型大行程7稳态机构样件，理论与试验结果基本一致，验证所提出的多稳态机构设计方法的可行性和有效性。

英文摘要：

Due to the strong nonlinearity of the snap-through phenomenon of the multistable mechanism, it is difficult to design and control the multistable characteristics including stable state number, stable positions, snapping threshold and travelling stroke. To solve the design problems caused by the uncontrollable state features of the multistable mechanisms, a novel magnetic-mechanical based multistable mechanism with large travelling stroke is proposed by introducing the spatial arranged magnets to assist the energy storage and release procedure of the mechanical system, with which the local minimal energy positions can be designed by properly incorporating the compliant mechanisms and multi-magnets. Considering the influence of the nonlinear mechanical deformation on the magnetic field distribution, the accurate mathematical model for analyzing the nonlinear snap-through characteristic is established based on the magnetic charged model and the pseudo rigid body model method. Additionally, the influence of the magnetic pole direction, the magnet number and their arrangement on the multistable characteristic is theoretically analyzed, which is validated by the FEM simulation. Accordingly, the energy criterion for the magnetic-mechanical coupled multistability is obtained, thus resulting in the relationship between the real stable state and pseudo stable state. With the prerequisites for multistable features, a novel heptastable mechanism is manufactured. The good consistency between the simulation and experimental results adequately validate the correctness of the proposed model.