An object is displaced alternately in opposite directions, using a hydraulic power unit having a rotatable body which includes the shaft of a hydraulic machine having electronically commutated valves. A motor drives the rotatable body. The hydraulic machine drives an actuator to displace the object in use. Energy is transformed from rotational kinetic energy of the rotatable body to elastic strain energy or elastic strain and gravitational potential energy of the object during a pumping phase and rotation of the rotatable body slows, but does not change direction. The potential energy then drives the hydraulic machine to motor and the rotatable shaft speeds up again, storing rotational kinetic energy. The displacement of the hydraulic machine is controlled throughout to match a time varying demand taking into account the varying speed of rotation of the rotatable shaft. The motor provides energy to compensate for losses and the process can repeat cyclically.

Disclosed example grip assemblies, such as for holding a sample for testing in a material testing machine, include: a core member extending along a central axis from a first end portion, configured to releasably mount the grip assembly to a crosshead, to a second end portion, wherein the core member comprises a body portion having a pneumatic cylinder enclosing a pneumatic volume; a pneumatic piston head arranged to be slidably received in the pneumatic cylinder and to be moveable along the pneumatic cylinder in a first direction to expand the pneumatic volume, and in a second, opposing, direction to contract the pneumatic volume; a housing, including a sleeve member coaxially mounted around the body potion; a sample holder disposed at the second end portion, configured to selectively apply a holding force to a sample for testing; and a driving member configured to contactingly engaging the sample holder.

A computer-implemented method for the probabilistic assessment of fatigue of component parts in the presence of manufacturing defects comprises the following steps: importing predefined input data concerning at least one part of a component to be assessed; distinguishing a surface region of the part from an internal region; determining the volume and stress/deformation applied to the surface region and to the internal region; assigning the distribution of defects to a group of elements defined by the user; determining the maximum dimension of the defect in each surface or internal region considered; determining the critical dimension of the defect in each surface region or internal region by considering the fatigue strength of the material at the number of cycles under consideration, the stress/deformation applied and the position of each surface or internal region; calculating the reliability of at least one of the surface or internal regions considered.

A test device of universal nail/screw holding power is provided. The device is capable of penetrating a nail/screw into a test piece at any angle and positioning the test piece on which a nail/screw is penetrated at any angle to test the nail/screw holding power. The device includes a base, two opposite supporting plates, two coaxial disks, an upper bearing plate, a lower bearing plate, a side bearing plate, a through groove, a trapezoid slot, and a plurality of trapezoid bolts on the same circumference. When the disk is turned, at least one trapezoid bolt is inserted into the trapezoid slot; when the at least one trapezoid bolt engages with the trapezoid slot and then is tightened up, the at least one trapezoid bolt and the trapezoid slot cooperatively limit the turn of the disk.

A method of controlling a mechanical testing instrument includes estimating a young's modulus, and applying force during a first time interval then comparing distance measured to expected distance; predicting a distance based on a first slope applying displacement distance and recalculating the slope; providing a corrected force applied for the proper displacement based on measured modulus and correction factor and adjusting into time and distance coherence; applying a force versus time regime interval and predict deformation at the end of the second interval measuring true deformation distance after the next interval; calculating the true slope based on the extrapolated actual slope; calculating a slope to apply for desired distance; and repeating measurement and correction steps, using the actual slope as the prediction basis. A system for carrying out the method is also disclosed using a data acquisition board.

A method and apparatus for geotechnical soil sampling in conjunction with the Cone Penetration Test (CPT) is provided. The apparatus involves a tubular whipstock cell affixed between push rods and the lower elements of a cone penetrometer. The whipstock cell includes a whipstock having a beveled face. The whipstock face is oriented towards a sampling window pre-formed in the whipstock cell. The apparatus also includes at least one push rod connected to the proximal end of the whipstock cell, and an elongated sampling rod dimensioned to be slidably moved through the at least one push rod en route to the whipstock cell. The apparatus additionally comprises a soil sampler residing at a distal end of the push rod. A method of taking soil samples is also provided herein.

A test device of universal nail/screw holding power is provided. The device is capable of penetrating a nail/screw into a test piece at any angle and positioning the test piece on which a nail/screw is penetrated at any angle to test the nail/screw holding power. The device includes a base, two opposite supporting plates, two coaxial disks, an upper bearing plate, a lower bearing plate, a side bearing plate, a through groove, a trapezoid slot, and a plurality of trapezoid bolts on the same circumference. When the disk is turned, at least one trapezoid bolt is stretch into the trapezoid slot; when the at least one trapezoid bolt engages with the trapezoid slot and then is tightened up, the at least one trapezoid bolt and the trapezoid slot cooperatively limit the turn of the disk.

Safety systems and material testing systems including safety systems are disclosed. An example material testing system includes: at least one actuator configured to control one or more operator-accessible components of the material testing system; an actuator disabling circuit configured to disable the at least one actuator; and one or more processors configured to: control the at least one actuator based on a material testing process; monitor a plurality of inputs associated with operation of the material testing system; determine, based on the plurality of inputs and the material testing process, a state of the material testing system from a plurality of predetermined states, the predetermined states comprising one or more unrestricted states and one or more restricted states; and control the actuator disabling circuit based on the determined state.

A method for creating a composite cable having at least one high-performance termination on at least one end. A high-performance termination is added to an end of a short synthetic tensile strength member. The strength of the tensile strength member and termination is then tested. Once tested satisfactorily, the short cable is spiced onto a long cable of the same type using prior art splicing techniques. The union of the short cable and the long cable creates a composite cable having a high-performance termination on at least one end. In most applications preferable to set the length of the short cable so that the interwoven splice will exist at a desired location.

A bottom cylinder for a high-temperature and high-pressure environment simulator of a high-fidelity corer is provided. The bottom cylinder includes a cylinder barrel. The bottom of the cylinder barrel is provided with a cylinder base. The piston is provided inside the cylinder barrel and divides an inner cavity of the cylinder barrel into a rodless cavity and a rod cavity. The piston is provided with a piston rod. The outer wall of the cylinder barrel is provided with an oil inlet hole communicated with the rodless cavity, an oil outlet hole communicated with the rod cavity, and a reserved hole. The lower end surface of the piston is provided with a first buffer ring, and the upper surface of the cylinder base is provided with a second buffer ring mated with the first buffer ring. The bottom cylinder is applied to the simulator for oil and gas resource exploitation.