A design method for manufacturing a prestressed shell having tuned bistability, wherein, to determine the appropriate prestress to be applied to the bistable shell, the method comprises the following operating steps: A). clamping a shell by applying a predetermined clamp having a curvature on a portion of an edge of the shell, wherein the prestress which is obtained by applying the clamp depends on a finite number of design parameters p i = { h i=1,2...; m i=1,2...; c}, wherein h i, m i are the parameters representative of the shape of the initial stress-free configuration of the shell, i.e. free from external constraints, and of the material, while c is the curvature of the clamp; B). defining a discrete shell model dependent on a small number of configuration parameters q i, wherein i<5, by projecting the non-linear shell model of Marguerre-von Kármán onto an appropriate finite dimensional space, wherein the projection does not significantly alter the elastic energy; C). drawing the stability maps in the space of the design parameters by means of the discrete representation of the elastic energy E(q i;p i) thus obtained, thereby determining the number and the shape of the stable equilibrium configurations of the clamped shell, which at each load level correspond to a particular choice of the design parameters; D). choosing the design parameters providing the necessary prestress to obtain the desired behaviour in terms of performance requirements, that are: • the shapes that the shell must assume during the loading process; • the critical transition loads F 1 and F 2 levels at which the transition between the different shapes must occur, by choosing a point whose corresponding clamped shell has only one stable configuration for F = 0, two for F 2 ≤ F ≤ F 1 and again one for F > F 1; wherein the critical transition loads are changeable also during the operation of the structure, to fulfill possible changes in the performance requirements, by providing an adjustable curvature of the clamp; thereby identifying the corresponding optimized shape of the shell when free from constraints. A). clamping a shell by applying a predetermined clamp having a curvature on a portion of an edge of the shell, wherein the prestress which is obtained by applying the clamp depends on a finite number of design parameters p i = { h i=1,2...; m i=1,2...; c}, wherein h i, m i are the parameters representative of the shape of the initial stress-free configuration of the shell, i.e. free from external constraints, and of the material, while c is the curvature of the clamp; B). defining a discrete shell model dependent on a small number of configuration parameters q i, wherein i<5, by projecting the non-linear shell model of Marguerre-von Kármán onto an appropriate finite dimensional space, wherein the projection does not significantly alter the elastic energy; C). drawing the stability maps in the space of the design parameters by means of the discrete representation of the elastic energy E(q i;p i) thus obtained, thereby determining the number and the shape of the stable equilibrium configurations of the clamped shell, which at each load level correspond to a particular choice of the design parameters; D). choosing the design parameters providing the necessary prestress to obtain the desired behaviour in terms of performance requirements, that are: • the shapes that the shell must assume during the loading process; • the critical transition loads F 1 and F 2 levels at which the transition between the different shapes must occur, by choosing a point whose corresponding clamped shell has only one stable configuration for F = 0, two for F 2 ≤ F ≤ F 1 and again one for F > F 1; wherein the critical transition loads are changeable also during the operation of the structure, to fulfill possible changes in the performance requirements, by providing an adjustable curvature of the clamp; thereby identifying the corresponding optimized shape of the shell when free from constraints. • the shapes that the shell must assume during the loading process; • the critical transition loads F 1 and F 2 levels at which the transition between the different shapes must occur, by choosing a point whose corresponding clamped shell has only one stable configuration for F = 0, two for F 2 ≤ F ≤ F 1 and again one for F > F 1; wherein the critical transition loads are changeable also during the operation of the structure, to fulfill possible changes in the performance requirements, by providing an adjustable curvature of the clamp; thereby identifying the corresponding optimized shape of the shell when free from constraints.