Optimisation of a cycle fatigue or cycle and high-cycle fatigue test rig

Method for optimising a low-cycle, and/or high-cycle, fatigue test rig, said test rig being intended to reproduce a support of turbine engine parts, including a support of at least one blade root on a recess projection of a rotor disc, and comprising a support member which is fixed to a mount and defines at least two bearing surfaces, and a test piece which is connected to traction means for loading the test piece so that it bears against the or each bearing surface of the member, the method comprising the steps of:

• determining variable, geometrical, parameters of the support member and/or the test piece, and ranges of variation of said parameters;
• determining at least one objective to be achieved or optimised, a variation of the values of at least some of the above-mentioned parameters affecting the objective;
• modifying one or more of the values of the above-mentioned parameters, in the respective ranges thereof, and determining those which make it possible to achieve or optimise the objective so as to identify optimised parameters;
• and
• producing a support member and/or a test piece based on fixed parameters and parameters optimised for equipping a new rig, or modifying the support member and/or the test piece of an existing rig based on the optimised parameters, wherein:
• the support member further comprising two middle portions respectively supporting the two bearing surfaces, each middle portion being connected, on the side opposite the traction means, by a first arm to a base for fixing to the mount and, on the side of the traction means, by a pair of second arms to ends of two parallel crossbars which are at a distance from one another, the opposite ends of the bars being connected by another pair of second arms to the other middle portion;
• the method includes among the variable parameters at least one dimension of the second arms of each pair, and/or the angle of inclination of said second arms with respect to the corresponding crossbar or with respect to the bearing surface of the corresponding middle portion.