The method comprises performing the following steps by means of processing representative data of the flexible porous structure:a) generating a first function (Fs) defining how the flexible porous structure changes shape when it is subjected to deformation；b) generating a second function (Fp) defining how a covered surface of the flexible porous structure changes when it is subjected to changes in shape；c) obtaining, by means of said function (Fs), reference porosity values of a reference region (CU-R) of the flexible porous structure in a reference configuration； andd) calculating the porosity of at least one deformed region (CU-D) of the flexible porous structure, from said reference porosity values and from said second function (Fp).
