Patent ID: 6023980
Filing Date: 2000-02-15
Classification: G01N

Abstract:
A test machine for applying static and dynamic stress loading to a test specimen, comprising:an inner frame being generally in the shape of a hollow tube and having opposing end plates along a horizontal axis;two sets of bellows, each of said bellows having an axis of motion parallel to said horizontal axis, and each of said bellows having an inner end and an outer end, said inner ends of one set of bellows attached to one of said end plates and said inner ends of the other set of bellows attached to the other of said end plates;a pair of bearing plates, each of said bearing plates attached to said outer ends of each said set of bellows, such that each said set of bellows is located between an end plate and a bearing plate;two stress rods, each one of said stress rods attached to one of said bearing plates and extending inwardly through an associated end plate;a pair of dynamic actuators, each one of said actuators being attached to one of said stress rods; anda pair of cylindrical couplers, each of said cylindrical couplers having an inner face with means for attaching one end of said test specimen, and each of said cylindrical couplers being attached to a stress rod and an actuator such that force applied to said stress rod by said bellows is transferred to said specimen and such that force provided by said actuators on said stress rods is transferred to said specimen;wherein said stress rods, said cylindrical couplers, and said actuators provide a predetermined natural resonance when said test machine is in operation with said test specimen.