Patent ID: 8601881

Claim:
A material sample ( 1 ) for testing material properties under biaxial load under rotation about its center line ( 17 ), with the material sample ( 1 ) having a circular disk shape and having a hub ( 12 ), a ring section ( 14 ), and an edge ( 11 ), with the edge ( 11 ) and the hub ( 12 ) being axially thicker than the ring section ( 14 ) located in between, with the ring section ( 14 ) being designed with a concave fillet ( 13 ) that is concentric to the center line ( 17 ) on the two respective sides of the material sample ( 1 ) and that extends from the hub ( 12 ) to the edge ( 11 ) and is curved at least in sections over its width, a rotating stay bolt ( 15 ) integrally connected to and extending from the hub ( 12 ) concentrically to the centerline ( 17 ) of the material sample ( 1 ) whereby the stay bolt ( 15 ) rotates with the hub, wherein the material sample ( 1 ) is a solid disk without a through-going centric hub bore, completely rotationally symmetric, or at least predominantly symmetric; the material sample being configured and arranged to rotate about the center line, and wherein the stay bolt ( 15 ), hub ( 12 ), ring section ( 14 ), and edge ( 11 ) are integrally formed from the same material into a unitary member.