Abstract: The invention concerns a method for defining scaled stresses indicating an estimation of the product reliability with maximum accuracy. It comprises a phase which consists in inputting characteristic parameters (1), defining a sequence of stresses and simulating occurrences of failure time (2), estimating the characteristic parameters with indication of trust intervals (3), estimating proportions of faulty parts (4), a phase of testing the accuracy of the estimation (5), a feedback on phase (2) defining the cycle of stresses in case of insufficient accuracy. That set of operations (6) is only simulated, but when the estimation of proportion is determined to be sufficiently accurate, the cycle of stresses is implemented on a real test. The inventive method can also be used to test electronic products sensitive to thermal or vibratory stresses as well as mechanical products sensitive to fatigue stresses.

Abstract: The invention relates to a method for preparing natural fibre-based composite materials containing natural binders and powdery proteins, comprising the following steps; adding a powdery protein adhesive binder to natural fibres having a moisture content of 1 15%; mixing the natural fibres together with the powdery protein adhesive; adjusting the moisture content of the composition to 6 24% w/w; and submitting the mixture to a heat pressure treatment to form the natural fibre-based material.