The solution of structural analysis problems, especially of shell structures, demands an efficient numerical solution strategy. Since unilateral contact problems are investigated, the shell model is formulated with respect to one of the outer surfaces, i.e., the shell formulation is surface-related. In particular, the investigation of textile reinforced strengthening layers will be carried out by this approach. The presented shell formulation assumes linear shell kinematics with six displacement parameters. This low-order shell kinematics produces parasitical strains and stresses, leading to poor approximations of the solution or even useless results. Therewith, extensions and/or adjustments of well-known techniques to prevent or reduce locking like the assumed natural strain (ANS) method, proposed in [14], and the enhanced assumed strain (EAS) method, suggested in [13], have to be performed. The effectiveness of the surface-related solid-shell element is finally demonstrated by a numerical example.