A racquet including a frame including a head portion, a handle portion, and a throat portion. The head portion is a tubular structure including inner and outer peripheral walls, each having inner and outer surfaces. The head portion of the racquet being formed of a fiber composite material. The fiber composite material includes a plurality of ply arrangements. Each includes a pair of plies defining first and second angles with respect to a composite axis. A section of the outer peripheral wall from the inner surface to the outer surface includes at least three ply arrangements overlaying each other, and the first and second angles of at least two of the at least three ply arrangements being at least 35 degrees. When the racquet is tested under a racquet torsional stability test, the racquet has an angular deflection of less than 5.5 degrees about a longitudinal axis.

A method is described for continuously evaluating mechanical and micro structural properties of a rolled metallic material (L) in a cold deformation process, subjected to combinations of deformation forces selected among compression forces, traction forces and bending moment applied at low deformation speed in a range comprised between 1*10.sup.−4 and 10*10.sup.−4 s.sup.−1 which corresponds to laboratory static conditions and at high deformation speed in a range comprised between 0.1 and 10 s.sup.−1 which corresponds to dynamic pp conditions, the method comprising the step of: —measuring characteristic parameters of the cold deformation process under dynamic conditions, comprising at least one value of temperature (T), deformation (ε) and deformation speed ({acute over (ε)}) of the rolled sheet (L); characterized in that it further comprises the steps of: —calculating the traction yield strength at high deformation speed (σ.sub.YD) according to equation (I), being: σ.sub.c a compression strength of the rolled sheet (L) when a compression force (Fc) is applied thereon; σ.sub.t a traction strength of the rolled sheet (L) when traction forces (Tin, Tout) are applied thereon; σ.sub.bend a strength due to the bending of the rolled sheet (L) when a bending moment is applied thereon; and m, n, p are a first, a second and a third parameter respectively being a function of continuously-measured operating conditions of the cold deformation process and being a function of the rolled sheet (L) in terms of chemical composition and of preceding operating conditions of a hot deformation process, in terms of hot-rolling start and end temperature, winding temperature and grain size; calculating the traction yield strength at low deformation speed (σ.sub.YS) according to equation (II), being: σ.sub.YD the traction yield strength at high deformation speed; f a statistical optimization factor between data measured at low deformation speed and at high deformation speed; α a first characteristic parameter of the rolled sheet (L) being a function of a chemical composition of the rolled sheet (L) and of operating conditions of a hot deformation process of the rolled sheet (L); and β a second characteristic parameter of the rolled sheet (L) being a function of the cold deformation process calculated as (III), being {acute over (ε)} the deformation speed, Q an activation energy of the deformation of the rolled sheet (L) evaluated through laboratory tests, R the Boltzmann constant of ideal gases, and T the temperature of the rolled sheet (L).

The invention relates to a method for determining the replacement state of wear of a rope made of a textile fibre material, wherein, in the course of using the rope, the elongation of the rope is monitored over its entire length and the rope is discarded if the elongation of the rope over the entire length exceeds a predetermined maximum value (%). The method according to the invention is characterized in that also the local elongation of a discrete rope section is monitored and the rope is discarded if the local elongation of the rope section exceeds a predetermined maximum value (%), with the maximum value of the local elongation of the rope section being greater than the maximum value of the elongation of the rope over the entire length.

A rigidity measurement apparatus is a rigidity measurement apparatus that measures rigidity of an object to be measured and includes a load estimator, a displacement calculator, and a rigidity calculator. The load estimator estimates a load applied to a measurement point set on the object to be measured by using a captured image of the object to be measured. The displacement calculator calculates a displacement of the measurement point by using the captured image. The rigidity calculator calculates the rigidity of the object to be measured by using the load and the displacement.

The present disclosure discloses a flexible display auxiliary device and a foldable mobile terminal. The flexible display auxiliary device includes a platform, a first stage, a second stage, a sliding mechanism and an enabling mechanism. The first stage is used for fixing the first end of the flexible display screen, the second stage is used for fixing the second end of the flexible display screen opposite to the first end. The second stage is fixedly arranged on the sliding mechanism, the sliding mechanism is arranged on the platform, the enabling mechanism is connected to the sliding mechanism to control the sliding mechanism to move on the platform so as to change the relative distance between the first stage and the second stage and change the tension on the flexible display screen. In the above manner, the present disclosure enables the flexible display to always be in a flat state.

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.

Provided is a material testing machine capable of giving an appropriate testing force to a testing piece. The material testing machine performs a three-point bending test on a testing piece and includes a support mechanism that supports the testing piece, an indenter that is connected to an ultrasonic oscillator and gives ultrasonic vibration to the testing piece by abutting against the testing piece, and a load mechanism that presses the indenter to the testing piece supported by the support mechanism. The support mechanism includes: a spherical seat that has a lower member equipped with a spherical-surface-shaped concave portion or convex portion, and an upper member equipped with a spherical-surface-shaped concave portion or convex portion having a shape corresponding to the concave portion or convex portion in the lower member; a holding portion; and a first movable member.

A loading device, a monitoring system, and a method thereof can measure stiffness of a structural member (SM) and monitor progress or property thereof over time. The loading device includes two types of displacement sensors, one type being an antenna. As the SM, which is in a magnetic or electromagnetic field and electromagnetically coupled to the antenna without contact, undergoes displacement under known loads, characteristics of the electromagnetic field coupling between the antenna and the SM change over time due to the displacement of the SM. The shift in the characteristics of the electromagnetic field coupling between the antenna and the SM can be used to determine the displacement of the SM. Based on the changes in the displacement over time, diagnosis of the SM being monitored over an evaluation period can be made. The loading device includes at least one movable frame to apply a preload to the SM.

A test apparatus used for simulating debonding between a carbon fiber reinforced polymer (CFRP) and concrete in a CFRP-strengthened structure consists of a primary structural block, a secondary structural block, an adjustable hanger, a receiving slot, an attachment mechanism, a pull-off disk, a connecting plate having a plurality of rods. The adjustable hanger and the secondary structural block are slidably positioned into the receiving slot that traverses into a structural body of the primary structural block. The adjustable hanger is mainly used during double-shearing tests and mixed-mode tests, wherein both shearing and peeling is analyzed in mixed-mode tests. The secondary structural block is used in double-shear tests, mixed-mode tests, single-shear tests, tension pull-off tests, and beam-bend tests. The attachment mechanism, which holds the primary structural block, the secondary structural block, and the adjustable hanger together, is also used during single-shear tests and beam-bend tests.

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.