An example material testing machine includes: a first crosshead; a first drive shaft configured to move the first crosshead when actuated; a housing comprising an air inlet and an air outlet; a drive motor within the housing and configured to actuate the first drive shaft; a motor drive circuit configured to provide electrical power to the drive motor; and a motor drive cooling system configured to cool the motor drive circuit, the motor drive cooling system comprising: a cooling fan configured to generate an airflow from the air inlet of the housing to the air outlet of the housing, wherein a total surface area of the air outlet is greater than a total surface area of the air inlet such that an air pressure of the airflow decreases from the air inlet towards the air outlet; a duct configured to direct a path of the airflow between the air inlet and the air outlet; and a heat sink thermally coupled to the motor drive circuit and positioned within the airflow in the duct.

A method for predicting a multiaxial fatigue life. The method includes: obtaining a first temperature rise value of a to-be-tested material in a first cycle; determining first inherent dissipation energy of the to-be-tested material in the first cycle according to the first temperature rise value and a time constant; and determining the multiaxial fatigue life of the to-be-tested material according to a first proportional value, the first inherent dissipated energy, axial fatigue test parameters and torsional fatigue test parameters; the first proportional value is a ratio of an axial strain amplitude to a torsional strain amplitude of a multiaxial fatigue test, the axial fatigue test parameters are configured to represent an axial fatigue resistance of the to-be-tested material, and the torsional fatigue test parameters are configured to represent a torsional fatigue resistance of the to-be-tested material.

The present invention concerns a device and method for selectively or simultaneously measuring shear strength and pore water pressure of a soil in the field. The device includes a rod adapted to be at least partially inserted into the soil and rotated. The rod has a soil engaging portion and an opposed coupling portion configured to be coupled to a torque applying machine or device. The device further includes at least one vane blade extending at least partially along and from the soil engaging portion of the rod for shearing the soil when rotated together with the rod. At plurality of pore water pressure sensors are operatively associated with at least one of the soil engaging portion and the at least one vane blade. The sensors are configured to sense pressure indicative of the pore water pressure of the soil while the at least one vane blade shears the soil.

A device is for detecting compaction and shear strength characteristics of an asphalt mixture during construction compaction. The device includes a fixed frame and a detection system. The detection system includes a display, a control panel, a test claw, an electric motor, a lift switch, a torque sensor and a temperature sensor. The control panel includes a power switch for controlling the electric motor and a speed regulator for controlling a rotation speed of the test claw. An output end of the electric motor is connected to an input end of the torque sensor, and an output end of the torque sensor is connected to an input end of the test claw. An output end of the test claw is provided with a claw-shaped blade. The claw-shaped blade is provided therein with the temperature sensor.

For improving the signal quality while simultaneously improving the function of test objects, a load measuring arrangement includes a test object and a load measuring device for measuring a load applied between a first and a second region of the test object. The test object has a transmission region receiving a major part of the load between the first and the second region. A secondary transmission element is connected to the first and second regions of the test object so as to receive a smaller portion of the load between the first and second regions in parallel with the transmission region. The load measuring device includes a magnetic field generating device for generating a magnetic field at the secondary transmission element, and a magnetic field detection device for detecting a magnetic field parameter changing due to the load at the secondary transmission element.

Provided is a repetitive moment generating device that can be used for a fatigue testing machine and allows for a change in an amplitude of a repetitive moment to be imparted on a test piece even during rotation of an eccentric weight. A repetitive moment generating device includes: eccentric weight members provided at shaft bodies in a state where the eccentric weight members intersect the rotatably held shaft bodies and in a state where the eccentric weight members are slidable in a direction that intersects the shaft bodies; sliders that are attached to the shaft bodies in a state where the sliders are slidable in a direction of shaft centers of the shaft bodies and in a state where the shaft bodies are able to idle; link mechanisms that convert sliding motion of the sliders in the directions of the shaft centers into sliding motion in a direction that intersects the shaft bodies and transmit the sliding motion to the eccentric weight members; handle that are operation means for causing the sliders to slide in the directions of the shaft centers of the shaft bodies; and the like.

Systems and methods for testing cable bending fatigue include a hollow body for at least one cable to pass through, a pair of primary gears, respectively located at both ends of the body, and connected by a transmission shaft and can be driven to rotate by a first motor via the transmission shaft, and at least one pair of secondary gears, each pair of secondary gears being respectively meshed with the pair of primary gears, and drivable to rotate by the meshed primary gears, wherein, both ends of the cable are respectively fixed to gear centers of a respective pair of secondary gears, and the body causes the cable in a bended state when both ends of the cable are fixed to the gear centers of the pair of secondary gears.

An electromagnetic multiaxial fatigue testing machine includes a test piece fixing platform and an electromagnet loading mechanism arranged on a frame, wherein the electromagnet loading mechanism includes a first loading device for bend loading, and a second loading device for axial and torsional loading. The first loading device includes a first permanent magnet and a first electromagnet with a direction of a magnetic force generated therebetween is orthogonal to an axial direction of a test piece; the second loading device includes a second permanent magnet and a second electromagnet mounted on a swinging pair with a direction of a magnetic force generated therebetween is parallel to the axial direction of the test piece.

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.

A torsional fatigue testing apparatus comprises: a cable holding device, a motion guiding device and a driving device. The cable holding device is provided for holding a cable to be tested to extend between a rotatable holder and a slidable holder. The motion guiding device is provided for converting the rotational motion of the driving device into a reciprocating linear sliding motion by means of linkage so as to alternately rotate the rotatable holder forwardly and reversely, and therefore to repeatedly twist, by the rotatable holder, the cable to be tested.