Abstract: Results of nonequilibrium Brownian dynamics simulations of the steady state and transient rheological behavior of nonlinear elastic dumbbell models in elongational flow is reported. The simulations include exa min ation of the effects of configuration dependent friction coefficients and spring parameter. The nonlinear random dynamical theory is used to analyze phase diagrams and an interpretation of no S shaped curves for the elongational viscosity or for the mean square end to end distance is gi...