A constitutive law in large transformations of soft structures has been ela
borated, starting from a micropolar constituve law, whereby a microrotation
takes into account the microstructure effect, rn fabric one undulation def
ines the mesoscopic scale. The hyperelastic law describes in a satisfactory
manner the uniaxial traction curve of the fabric. (C) 2001 Academie des sc
iences/Editions scientifiques et medicales Elsevier SAS.