The invention relates to a device for carrying out bending tests on panel-shaped or beam-shaped samples (1), in which two rotary drives are arranged at a distance from one another and a flange (3) is fastened to each of the drive shafts of the rotary drives, said drive shafts being oriented parallel to one another. At least two bar-shaped bending elements (2) oriented parallel to the axis of rotation of the drive shafts and arranged at a distance from the axis of rotation and at a distance from one another are provided on each of the flanges (3). A panel-shaped or beam-shaped sample (1) can be introduced between the two bar-shaped bending elements (2) on the two flanges (3). In the event of rotation of the rotary drives in opposite directions of rotation, bending forces are exerted on the sample (1) and each of the two rotary drives can be controlled individually and connected to an electronic open-loop or closed-loop control unit.

A racquet extends along a longitudinal axis and is capable of being tested under a racquet lateral bending test and a racquet torsional stability test. The racquet lateral bending test includes mounting the racquet in a first orientation to a first test fixture at a first longitudinal location, attaching a clamp to the racquet at a second location, operably engaging a deflection indicator to the clamp, applying a first predetermined weight to the racquet at a third location, and removing the first weight to obtain a lateral deflection measurement of the racquet with respect to the longitudinal axis. The racquet torsional stability test includes mounting the racquet to second and third test fixtures at sixth and seventh locations of the racquet, respectively, placing a third predetermined weight on an arm extending from the second test fixture, removing the third predetermined weight to obtain an angular deflection about the axis. The racquet comprises a frame including head and handle portions and a throat portion positioned between the head and handle portions. The head portion forms a hoop that defines a string bed plane. When the racquet is tested under the racquet lateral bending test, the racquet has a lateral deflection of at least 6.0 mm when measured in a direction that is parallel to the plane and perpendicular to the axis. When the racquet is tested under the racquet torsional stability test, the racquet has an angular deflection of less than 5.0 degrees about the axis.

A test method for characterizing the mechanical properties including the surface adhesion energy on the basis of the experimentally derived P-A relationship,

where P means the indentation load under the penetration depth h of an indenter pressed onto a test specimen with surface adhesion, and

A means the contact area of indentation at the contact radius a under the applied load of P.

This test method enables the implementation for quantitatively as well as simultaneously characterizing the adhesion energy as well as the various mechanical properties (elastic/elastoplastic/viscoelastic properties) of soft materials.

Novel markers that can be attached physically to a tensile specimen with a center guide to allow for measuring correct strain, as well as a binder that fixes and holds a pin guide to its location on the specimen during the test.

According to one embodiment described herein, the forces of a shrink film may be measured. The method of measuring the forces may include providing a shrink film processing unit and a testing vehicle moveable within the shrink film processing unit, positioning a shrink film around the testing vehicle, processing the wrapped testing vehicle by shrinking the shrink film around the testing vehicle as the testing vehicle moves through the shrink film processing unit, and measuring the forces applied by the shrink film on the testing vehicle with one or more force sensors at multiple separate sensor positions on the exterior of the testing vehicle during processing, after processing, or both.

A tennis racquet extending along the longitudinal axis and capable of being tested under a forward/rearward bending test and a torsional stability test includes a frame having 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. At least the head portion and the throat portion of the racquet are formed at least in part of a fiber composite material. The throat portion includes a pair of throat elements. When the racquet is tested under the forward/rearward bending test, the racquet has a forward/rearward deflection with respect to the longitudinal axis of at least 9.0 mm when measured in a direction that is perpendicular to the string bed plane and perpendicular to the longitudinal axis. When the racquet is tested under the torsional stability test, the racquet has an angular deflection of less than 5.5 degrees about the longitudinal axis.

A closed-loop control method based on a testing machine for accurately controlling the loosening of a bolt transverse load is disclosed. The testing machine for accurately controlling the loosening of the transverse load comprises a load generating motor, a load transfer mechanism, a load control motor and a load control mechanism. The control method of the present invention controls the load generating motor to drive the load transfer mechanism based on control commands, displacement signals collected by the displacement sensor and force signals collected by an S-shaped column type pressure sensor. The testing machine for the looseness of the bolt transverse load is essential in the aspect of exploring a looseness law of a bolt, and can be used to simulate load bearing conditions of the bolt. However, under the condition that some bolts bear constant force load transversely, the testing machine is not used or is inaccurate. The control method of the present invention can accurately control the load transverse load to be stable, especially can ensure constant transverse load and can also simulate the transverse load bearing situation of the bolt more accurately and more comprehensively.

The present disclosure relates to bendable and/or foldable articles and uses thereof and to a method of providing bendable and/or foldable articles. The articles are of translucent and brittle material, such as glass, glass ceramic, ceramic or crystals. The articles may be used as a display cover such as a protecting cover in displays in, for example, smartphones, tablet computers, or TV devices. The articles may also be used as a substrate for electronic components, such as OLEDs or LEDs.

Apparatus and methods of evaluating brittleness by measuring force applied to an electrode specimen by simulating a wound state of a jelly-roll type electrode assembly are disclosed herein. In an embodiment, a brittleness evaluation apparatus includes a jig unit, a driving unit, and a measurement analyzing unit. The jig unit includes two jigs, a groove formed between the jigs, a pressing plate, and guides. The jigs facing each other and have top surfaces formed in a horizontal plane and configured to receive a specimen arranged on the top surfaces along a length direction extending between and along the top surfaces. The pressing plate is arranged perpendicular to the length direction and configured to cause the specimen to bend by descending into the groove. The guides are located on each of the top surfaces of the jigs and configured to prevent distortion of the specimen during descent of the pressing plate.

A system for universal testing of metal sheet formability is described. The system discloses a cylinder barrel including two pistons for testing formability of the metal sheets. The driving force is provided by the hydraulic pressure of an incompressible fluid. The present application also describes an apparatus to perform various formability tests on metal sheets such as the bulge test, Nakazima test, Marciniak test, cupping test, and the blanking test. The system can also be used in hydroforming metal sheets.