Apparatus and method for fatigue testing

A method of simulating life of a rotor blade mounting feature mounted in a complementary rotor disc mounting feature comprises the steps of providing two specimen mounting features ( 37 ) each having portions defining pressure faces matching in profile respective faces of the rotor blade mounting feature; providing a fixture ( 38 ) having two opposed mounting features ( 39 ) each having portions defining pressure faces ( 78 ) matching in profile respective faces of the rotor disc mounting feature; mounting the specimen mounting features ( 37 ) in the fixture mounting features ( 39 ); applying a first load to the specimen mounting features ( 37 ); measuring a strain in a region ( 86 ) of the fixture ( 38 ) between the fixture mounting features ( 39 ); applying a second load to the fixture ( 38 ), the second load being substantially perpendicular to the first load; and controlling the second load in response to the measured strain. A high cycle load may simultaneously be applied to the specimen mounting features ( 37 ). Claims are also included for an apparatus ( 10 ) for carrying out the method.