Design Of Snap-through Characteristic Of Multistable Structures Based On Cross-section Configuration Optimization

The multi-stable structures were widely used in sophisticated systems such as sensors or switches actuators and other fields. These structures have advantages in less energy consuming, rapid response and high accuracy. However, many studies show that the cross-section configuration and shape of structures decide the bistable characteristics, so more and more researches concentrated on changing the size of structures to adjust the characteristics of bistable structures, which brought in difficulties on designing bistable structures by not changing bistable structures’ geometric size. On dealing with this problem, a method of designing of snap-through characteristic of multistable structures according to cross-section configuration optimization was come up, the following researches were carried out.1) In order to deal with the snapping threshold inequality of the forward and backward strokes of bistable structures, a method of designing of snap-through characteristic of multistable structures according to cross-section configuration optimization was come up. By introducing snapping force, stable position maintaining force and their ratio to represent the bistable characteristic parameter, the optimization model for specific characteristic was established, which contained a) a symmetrical optimization model was established to control snap thresholds. A series of new configuration bistable structures with different bistable characteristics were obtained and the thresholds were adjusted. b) An asymmetrical optimization model was established to control snap thresholds. By designating the minimum snapping force and specific bistable characteristic parameter as the goal, and taking the local elements’geometrical size number and their positions as the variables, the numerical simulation shows that the snap threshold force can be decreased by 47.8% with the bistable characteristic parameter varies within 1%.2) The obtained bistable cosine-shaped beam’s frequency response was analyzed. The curve of Impact response and harmonic excitation response were obtained. The result shows that bistable structures can used in shock absorber for their amplitude-frequency particular characteristics.3) Two methods of designing multi-stable structures were come up. a) A design method of Multistable truss structure, by designing the truss’ angle of connection, length and the form of reinforced rib, a tristable truss. The numerical simulation shows that by bring in reinforced rib, the method of multistable truss’ designation without changing macro size was effective, b) A method of designing multi-stable shells based on multi- swell. By designing single swell’s cross-section configuration multi-swell shell’s multistable characteristics was changed, the numerical simulation verify the effectiveness of the proposed method.Give special thanks to National Nature Science Foundation of China (51105059, 11372063) and Enterprises, Universities and Research Project of AVIC (CXY2011DG34) which greatly supported this paper.