Design And Analysis Of Recoverable Buffer Connector Structures

Bolt fasteners are usually used to ensure that the structures can be closely connected under normal working conditions.However,for equipment under severe shock and vibration working conditions for a long time,strong impact force will be directly transmitted to all parts of the structure through these connectors.Light impact will affect the accuracy of the equipment,and heavy impact will directly cause damage to the equipment.In addition,impact may have multiple effects in a short time In terms of structure,the connector must also have recoverable performance to resist secondary impact.In this paper,the static load high stiffness buffer connection with recoverable performance used in matching bolt connection is studied,and the simplified calculation of bolt connection is discussed in detail,and a simplified method of bolt connection which can greatly improve the efficiency and accuracy of large equipment analysis for static and dynamic characteristics is given.Specific research contents and achievements include:(1)A design scheme of buffer structure with resettable and high static load stiffness characteristics.Based on the theoretical analysis of the basic linear impact dynamic model,the stiffness characteristic curve of the recoverable buffer structure is designed.According to the stiffness characteristic curve,the structural principle buckling which can meet the design requirements of the buffer structure in this paper is found.In this paper,the plumpness,bi-stability and unidirectional buffering of curved beam stiffness are studied in detail.According to the actual buffering requirements,a kind of buffering structure with recoverable and high static load stiffness characteristics is designed.In order to make the buffer structure be able to quantitatively aim at the impact load of different magnitude,a set of design flow suitable for the buffer structure is formed.The results of transient dynamic analysis show that the proposed buffer structure can meet the requirements of recoverable buffer.(2)The calculation method of equivalent stiffness of bolted connection system under pretension.In this paper,the difference of equivalent stiffness calculation results of bolts and connected parts under preload in different bolt connection calculation systems is studied.The distribution law of strain in the local part of the connected part is given by using the finite element technology,and the calculation formula of the local stiffness of the connected part is obtained according to the distribution law.After that,the influence of local deformation of screw thread on the stiffness calculation of bolted connection system is considered,and the calculation formula of bolt stiffness in the original manual is modified.(3)A simplified method of bolt connection for dynamic analysis of large assembly body is presented.In order to solve the problems of complicated modeling,high calculation difficulty and hard to guarantee the accuracy in the dynamic analysis of large-scale assembly,this paper first compares and analyzes the conventional bolt connection simplification strategies,and then according to the characteristics of the dynamic analysis of large-scale assembly,presents several bolt connection simplification strategies suitable for such analysis problems: single beam model,beam + connection element model,Entity + connection element model,and a comparative analysis of these schemes.The results show that for the bolt connection modeling method without considering the preload,the simplified model of solid + connection element is better in terms of accuracy and complexity of preprocessing.