Design Of Negative Stiffness Shock Absorber Based On Two-bar Tensegrity Structure

The research and development of vibration reduction equipment is an important part of China’s high-quality development.With the industrialization development of our country reaching a certain height,the development of the vibration equipment industry involves multiple fields and disciplines,which limits the production and manufacturing of high-quality cutting-edge equipment parts.For large-scale ultra precision machining and manufacturing technology,what is needed is the support of precision vibration isolation technology.The traditional linear shock absorber has a simple structure,and due to its theoretical basis and structural limitations,it is difficult to ensure that the shock absorber mechanism has high bearing capacity and low dynamic stiffness for precise vibration isolation applications.Therefore,this article studies and implements a two bar tension integrated vibration reduction platform mechanism with negative stiffness characteristics,which is a nonlinear negative stiffness damper with high static stiffness and low dynamic stiffness characteristics.Firstly,conduct integrated design of negative stiffness components and tensioned overall structures.By analyzing the stiffness of negative stiffness units and addressing the low stiffness characteristics and stability issues of negative stiffness structures,a nonlinear negative stiffness shock absorber is constructed by combining the two bar tension integral structure with negative stiffness.The tension integral mechanism has high deformation and strong self-adaptability,allowing the designed shock absorber to have a wider damping bandwidth and ensure its structural stability.Secondly,establish the mechanical model of the negative stiffness tensegrity structure shock absorber,study the statics characteristics of the negative stiffness tensegrity structure shock absorber,analyze and calculate the compression of the shock absorber,input MATLAB for parametric model calculation and analysis,obtain the three-dimensional curved surface graphics of load force and relative displacement,and obtain the realization of the negative stiffness characteristics of the negative stiffness tensegrity shock absorber.Import the parameterized model of the overall three-dimensional structure of the vibration damping platform into Adams,simulate the vibration of the shock absorber under simple harmonic excitation force,and obtain that the shock absorber structure designed in the article can alleviate 60% of the impact vibration amplitude.The analysis shows that the negative stiffness structure of the compression spring is an elastic structure that captures energy during the transmission of vibration energy by the shock absorber.Finally,design and complete the manufacturing and assembly of physical experimental prototypes,and conduct pressure loading testing experiments and harmonic excitation vibration reduction experiments.The experimental results show that the shock absorber has high isolation performance within the negative stiffness range of the system,especially in the low frequency range,and also has high bearing capacity within the effective range of isolation.By adjusting the deformation of the elastic components of the negative stiffness mechanism,the natural frequency of the shock absorber can be reduced and the effective isolation frequency of the shock absorber can be increased.Among them,excellent vibration reduction performance is achieved by combining the vibration reduction of negative stiffness structures with the vibration reduction of tensioning mechanisms.Through complementary advantages,the isolation bandwidth of the shock absorber is widened,and the isolation performance is significantly enhanced.Demonstrate the effectiveness of vibration reduction through experiments.