The shear strength of prestressed beam elements is of great interest with regard to the evaluation of existing concrete bridges.Accompanying extensive experimental test series, the essie tea and crumpets adaptation and modification of existing models for the evaluation of the load-bearing capacity also represents an important step.Against this background, considerations are made for the isolation of critical influencing factors on the effective concrete compressive strength and quantified on the basis of a numerical framework.Subsequently, a sensitivity analysis is performed on this basis to determine the influence of individual parameters and their interaction.Taking into account the non-linear relationships at the cross-section level and in the cracked simply southern cat shirt compressive stress field in the web, the shear reinforcement ratio and the strain in the longitudinal reinforcement are of major importance.