A system can include a torsion applicator (e.g., a torsion motor and shaft) configured to apply a torque to a test article that is additively built on and attached to a build plate. The system can include at least one twist sensor and at least one torque sensor. A method for determining quality of an additively manufactured article or batch thereof can include torsion testing at least one additively manufactured test article that is built on and attached to a build plate while the at least one test article is still attached to the build plate.

A sports racquet capable of being tested under a racquet vibration test, and including a frame extending along a longitudinal axis. The frame includes a head portion, a handle portion, and a throat portion positioned between the head portion and the handle portion. The head portion forms a hoop that defines a string bed plane. The throat portion includes a pair of throat elements. At least the head portion and the throat portion of the racquet are formed at least in part of a fiber composite material. The head portion including a forward hoop surface and a rearward hoop surface. The distance between the forward and rearward hoop surfaces defines a beam height distance. The head portion has a maximum beam height distance of at least 19 mm. When the racquet is tested under the racquet vibration test, the racquet has a vibration of no greater than 130 Hz.

A racquet includes a frame extending along a longitudinal axis. The frame includes head and handle portions, and a throat portion positioned between the head and handle portions. The head and throat portions are formed at least in part of a fiber composite material. The material includes a plurality of ply arrangements. Each of the arrangements includes one ply having a first plurality of fibers defining a first angle with respect to a composite axis, and another ply having a second plurality of fibers defining a second angle with respect to the composite axis. The first and second angles are substantially the same except the angles have opposite polarities with respect to the composite axis. The head portion includes at least three arrangements overlaying each other, and the first and second angles of at least two of the at least three arrangements are at least 35 degrees.

A system can include a torsion applicator (e.g., a torsion motor and shaft) configured to apply a torque to a test article that is additively built on and attached to a build plate. The system can include at least one twist sensor and at least one torque sensor. A method for determining quality of an additively manufactured article or batch thereof can include torsion testing at least one additively manufactured test article that is built on and attached to a build plate while the at least one test article is still attached to the build plate.

A system can include a torsion applicator (e.g., a torsion motor and shaft) configured to apply a torque to a test article that is additively built on and attached to a build plate. The system can include at least one twist sensor and at least one torque sensor. A method for determining quality of an additively manufactured article or batch thereof can include torsion testing at least one additively manufactured test article that is built on and attached to a build plate while the at least one test article is still attached to the build plate.

A system can include a torsion applicator (e.g., a torsion motor and shaft) configured to apply a torque to a test article that is additively built on and attached to a build plate. The system can include at least one twist sensor and at least one torque sensor. A method for determining quality of an additively manufactured article or batch thereof can include torsion testing at least one additively manufactured test article that is built on and attached to a build plate while the at least one test article is still attached to the build plate.

A system can include a torsion applicator (e.g., a torsion motor and shaft) configured to apply a torque to a test article that is additively built on and attached to a build plate. The system can include at least one twist sensor and at least one torque sensor. A method for determining quality of an additively manufactured article or batch thereof can include torsion testing at least one additively manufactured test article that is built on and attached to a build plate while the at least one test article is still attached to the build plate.

Methods and systems are provided for a torsional material testing system, which includes a rotatable actuator, such as a motor, configured to perform a torsional material testing operation. During a torsional material testing operation, a virtual interlock is configured to engage or disengage with the actuator to prevent or allow rotational movement of the actuator (e.g., during a setup state or during a torsional material testing operation, respectively). A control circuitry is employed to control the virtual interlock as well as the torsional testing system based on one or more operational states before, during, or after a material testing process.

A system for sampling aerosols, for purpose of predictive analyses, from fractured test specimens is provided. The system includes a test enclosure, a load apparatus, and an aerosol sampling pack in fluid communication with the test enclosure. The test enclosure is sized to partially or completely receive the test specimen therein, and the load apparatus is configured to impart a mechanical load (e.g., tension, bending, torsion, shear forces, or compression) on the test specimen. The aerosol sampling pack receives solid aerosols that are generated upon fracture of the test specimen.

The present application relates generally to moving die rheometers, and more particularly to moving die rheometers that employ a variable eccentric cam. In one aspect, the eccentricity produced by the cam may be adjusted using shims of different thickness to alter the position of the post on the cam.