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 seat belt test apparatus for testing a safety restraint system for a vehicle comprises a first, a second, and a third test stand, an impactor apparatus, and a resistor apparatus. The first, a second, and a third test stand are selectively fixed to a test bench. The first, second and third test stands each comprises a pulley disposed proximate a top end of each of the first, second, and third test stand. The first test stand further comprises a first pretensioner mount. The third test stand further comprises a second pretensioner mount.

An apparatus for measuring a deformation stiffness of an article includes a force measuring means configured to measure a force generated in a thickness direction of the article; a thickness measuring means configured to measure a thickness of the article; and a data processor configured to differentiate force with respect to thickness to calculate the deformation stiffness of the article, wherein each of the force and the thickness are a result of a volume change of the article.

The invention provides a drop hammer height adjusting device for high strain detection of a pile foundation, the device comprises: a cross beam support frame, an avoiding hole is opened in the middle of the surface of the cross beam support; a track extending through the avoiding hole, a tooth group is arranged on each of two surfaces of the track bar, and abutting sliding blocks are further arranged at two sides of the track bar. The abutting sliding block is cooperated with the tooth group to limit the position of the track bar. The invention overcomes the significant disadvantages of the existing detection devices, the efficiency of obtaining qualified test signals is improved by the rapid and accurate height adjustment and test, and the precision and efficiency of high strain detection of a foundation pile are greatly improved.

According to the embodiments disclosed herein, in a press-fitting test for measuring physical properties of a test object by pressing an indenter against the test object and measuring the load and displacement, the measured displacement value is corrected in real time in consideration of the amount of deformation according to the load of the load cell, and thus an accurate load-displacement curve can be derived, even when the amount of deformation of the load cell is included in a measured value of a displacement sensor.

A system for simultaneously measuring the indentation hardness properties, span properties, and resilience properties of a mattress includes a first indentation means and a second indentation means, and means for urging the first indentation means and the second indentation means into the mattress with a predetermined force, and also includes laser means for projecting a laser line configured to map, preferably by photographic triangulation, the amplitude, shape, and time-dependency of the resultant deflection of the mattress surface between the first indentation means and the second indentation means. A method for simultaneously measuring the indentation hardness properties, span properties, and resilience properties of a mattress is also provided.

A mechanical testing apparatus for a specimen is presented. The mechanical testing apparatus comprises a drop table system and a Hopkinson bar. The drop table system has a drop carriage. The Hopkinson bar is positioned parallel to a motion of the drop carriage and connected to the drop table system by the specimen.

An apparatus for testing paving samples includes a base that includes a paving sample tray about the cabinet and configured for translation relative to the cabinet. A roller is configured for imparting compressive forces to a sample carried by the sample tray. An arm is configured for moving the roller from a stowed position to an in-use position where the roller contacts the sample. A cylinder assembly having a piston therein supplies pressure forces to the arm to move the arm from the stowed position to the in-use position, wherein a depth of travel of the arm is limited by the sample. As the sample is compressed, the depth of travel increases. A measurement device is in communication with the cylinder for determining an amount of travel of the arm to thus determine an amount of compression of the sample.

A glass stress test method includes breaking a glass, analyzing a shape of a crack of a broken portion of the glass in a plan view, finding a breakage origin of the glass based on the shape of the crack in the plan view, analyzing a cross-section of the breakage origin, and calculating a stress of the glass based on a cross-sectional analysis result of the breakage origin. The stress of the glass is calculated as a value proportional to a floor constant defined by a condition of a floor surface disposed when the glass is broken.