Joint member stiffness in a bolted connection directly influences the safety of a design in regard to both static and fatigue loading, as
well as in the prevention of separation in the connection. This work provides a new simple model for computing the member stiffness in
bolted connections for both fully and partially developed stress envelope fields. The new model is built using a stress distribution polynomial of third order. Finite element analysis (FEA) is performed for some joints geometries, and the results are used to estimate the best analytical envelope angle in the proposed analytical model that gives suitable convergence between the compared results. An experimental
effort is exerted to validate the accuracy of a suggested model. When analytical results are compared with FEA results and experimental
data, the maximum absolute percentage errors are found to be 2.69 and 14.69, respectively. Also, a good agreement is obtained when
the analytical results are compared with other researchers’ results.