The HYGROPOLYM project will open up an innovative field of activity in the field of sustainability under conditions of use of organic matrix polymers and composites. The project is based on two existing equipment (traction-tortorion on laboratory test specimens and tensile-tortion-pressure on structure) and will open the field of experiments in humidity and temperature at the scale of the structure. HYGROPOLYM has the following objectives: — Test laboratory test pieces in multiaxial loading (hygrometry and temperature). — Understand the physical mechanisms. — Propose models for calculating lifetime. — Test real components under fatigue loading (strong loads).