Normal forces of magnetorheological fluids under oscillatory shear

► Normal forces under oscillatory shear mode are firstly systematically investigated. ► In linear viscoelastic region the normal forces keep a firm value while in nonlinear viscoelastic region the normal forces fluctuate clearly ► Three regions can be obtained through the plot of normal forces with strain amplitude. ► Temperature effect on the normal forces is opposite for the low and high magnetic field.