A new computational method for threaded connection stiffness

Abstract

For designing bolted connections in machinery applications, it is necessary to estimate the stiffness of the threaded connection. This work provides a new method for computing the stiffness of engaged screw in bolted connections according to the load distribution in screw thread. Finite element analysis is performed by building the three-dimensional model of threaded connection. A set of tensile tests are exerted to validate the accuracy of the suggested model of threaded connection. A good agreement is obtained when the analytical results are compared with finite element analysis results, experimental data, and Yamamoto method. Results reveal that the ultimate strength of thread connections is obviously lower than that of thread material. In addition, the results of calculation and finite element analysis indicated that increasing Young’s modulus of material and the engaged length or decreasing thread pitch could increase the stiffness of the thread portion of a bolt and nut.