Abstract: For purpose of assessing the performance of load relief on launch vehicle, an assessment method based on steady state analysis is proposed. In addition to the criterion of load angle on of sideslip, the criteria of attitude deviation, engine deflection angle and trajectory deviation are also adopted. The bias effect of structural disturbances and the counteract effect to wind of translational motion are taken into consideration in this method. The influence mechanism of attitude dynamics parameters changes by wind shear is derived. Case study results indicate that, under the effect of typical wind field of steady wind & shear wind, load relief achieves acceptable performance in all the four assessment criteria, and greatly mitigates the problem of attitude parameters excessive change by wind shear.

Key words: Launch vehicle, Load relief, Wind shear, Structural disturbance, Performance assessment