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 slip test device includes a test member, a slip sensor, a pressing machine, a pressing force meter, a holding part, and a displacement meter. The pressing machine whose movement in a loading direction of the test member is constrained is configured to press a sample against a side of the test member that is an end portion of the test member in a direction perpendicular to the loading direction and with the sample sandwiched between the pressing machine and the test member. The holding part holds the sample between the test member and a pressing part. The pressing force meter measures a force with which the sample is pressed against the test member. The displacement meter measures the movement of the test member in the loading direction. The slip sensor measures a sliding motion of the sample in the loading direction relative to the pressing part or the test member.

An apparatus for measuring a degree of cure and a specific volume of a packaging material is provided, including: an upper load module configured for driving the rotation of an upper ball screw via an upper servo motor such that a force plate coupled to the upper ball screw moves downward and is thus positioned; a lower load module having a lower ball screw operating and moving via a lower servo motor such that a load joint group connected to the lower ball screw generates a corresponding displacement; an upper film cavity module connected to the upper load module; and a lower film cavity module disposed on the lower load module. The displacement of the load joint group enables a push rod to move upward. A heating pipe keeps constant the temperature of a subject to be measured in a cavity of the lower film cavity module.

A method of determining a minimum wall thickness for a pipe joint for use in a subsea pipeline comprises the steps of: i) determining an internal diameter of the pipe joint; ii) determining a minimum allowable hydrostatic pressure at the depth at which the pipe joint is to be used; iii) determining a target wall thickness for the pipe joint, the target wall thickness corresponding to the internal diameter and the minimum allowable hydrostatic pressure; iv) manufacturing a plurality of preliminary pipe joints having the internal diameter and the target wall thickness; v) carrying out external pressure collapse tests resulting in data representative of the hydrostatic collapse pressures at which the plurality of preliminary pipe joints collapse; vi) determining a probability distribution corresponding to the data based on a statistical tail model derived from Extreme Value Theory; vii) determining from the probability distribution a hydrostatic collapse pressure occurring with a probability of 10.sup.5 or lower; and, viii) determining a wall thickness of the pipe joint corresponding to the internal diameter and the hydrostatic collapse pressure.

A portable flexure fixture including a fixture housing, a translatable plug, a load ring, and a support ring. The fixture housing includes a first end opposite a second end, a plug receiving opening extending into the first end and a test opening extending into the second end. The support ring is disposed in the fixture housing. The translatable plug is insertable into the plug receiving opening of the fixture housing and is translatable in both a sample engaging direction and a sample releasing direction. Further, the load ring is coupled to the translatable plug and is positioned at a sample facing end of the translatable plug such that translation of the translatable plug in the sample engaging direction translates the load ring in the sample engaging direction and translation of the translatable plug in the sample releasing direction translates the load ring in the sample releasing direction.

A method for testing for hydrogen embrittlement, including mounting a container around a steel alloy test specimen, the container having a closed bottom below a notched area on the test specimen and an open upper end above the notched area; applying a tensile load to the test specimen and sustaining the load for a selected duration to incubate potential hydrogen embrittlement cracks with a sub-critical flaw size if sufficient hydrogen in dangerous levels is present in the test specimen; then, while sustaining the load, dispensing a cryogenic fluid into the container, immersing and chilling the notched area, reducing the sub-critical flaw size for any hydrogen embrittlement cracks incubated; and with the sustained load, fracturing the notched area if the sub-critical flaw size of any hydrogen embrittlement cracks incubated reaches a critical flaw size.

Methods of testing a monument that is attached to a floor of the aircraft. The testing uses a compliance matrix based on attachment points where the monument is attached to the floor of the aircraft. The testing uses a test monument that is equipped with extension members and load cells positioned at the corresponding attachment points. A test load is applied to the test monument and reaction loads are determined at each attachment point. During the test period, the compliance matrix and reaction loads are used to calculate displacements at each attachment point. Each of the extension members are then adjusted by the corresponding displacement. At the end of the test period, determination is made as to whether the test monument is capable of sustaining the predetermined load and adjusted displacements at the attachment points.

A system for in-situ testing of mechanical properties of materials in static and dynamic load spectra, that includes: an Arcan biaxial clamping subsystem, a press-in test subsystem, a biaxial fatigue test subsystem, a biaxial pre-tension loading subsystem, a signal detection subsystem, and a support and adjustment subsystem. A combined guide mechanism in the Arcan biaxial clamping subsystem is rigidly connected to a guide mechanism support block, an x-direction force sensor base and a y-direction force sensor base in the support and adjustment subsystem by threaded connections, respectively. A laser transmitter, a voice coil motor and a laser receiver in the press-in test subsystem are rigidly connected to a two-degree-of-freedom electric moving platform for the laser transmitter, a two-degree-of-freedom electric moving platform for the voice coil motor and a two-degree-of-freedom electric moving platform for the laser receiver in the support and adjustment subsystem by threaded connections, respectively.

A test apparatus comprises a probe movably mounted relative to a carrier. The probe comprises an end portion with a surface area of about 5 mm.sup.2 or less. The test apparatus can be used in methods of determining a crush strength of an edge of a substrate. Methods can comprise aligning the probe with a test location of the substrate at a predetermined angle relative to a probe axis. Methods can further comprise applying a mechanical force to the test location with the probe in the direction of the probe axis. Also, methods can comprise increasing the mechanical force applied by the probe until the substrate cracks or a predefined force applied by the probe is reached. Based on the mechanical force applied by the probe, a crush strength of an edge can be determined.