On the sensitivity of Finite Element results in the calculation of the lateral thrust for all-steel buckling-restrained braces

•The difficulty of computing the lateral thrusts in buckling-restrained braces is discussed.•The main cause for this is identified in their sensitivity to imperfections.•A comparison is done among several FEM models for the choice of an “optimal” one.•An analysis of damage and of asymmetric tension/compression behavior for the BRB core steel is performed.•The difficulty in the accurate computation of the lateral thrust in BRB is proved numerically.