Abstract: A method of determining a noise or vibration response of a vehicle subassembly may include transmitting, via a controller, an input torque control signal to a first motor of a test apparatus. The first motor is mountable on a test fixture of the test apparatus and is configured to be coupled to the vehicle subassembly. The input torque control signal causes the first motor to provide an input torque characterized as a third derivative Gaussian function. The method further includes receiving a response of the vehicle subassembly to the input torque, and executing a control action with respect to the vehicle subassembly, via the controller, based on the response.

Abstract: A system can include a torsion applicator (e.g., a torsion motor and shaft) configured to apply a torque to a test article that is additively built on and attached to a build plate. The system can include at least one twist sensor and at least one torque sensor. A method for determining quality of an additively manufactured article or batch thereof can include torsion testing at least one additively manufactured test article that is built on and attached to a build plate while the at least one test article is still attached to the build plate.

Abstract: A system can include a torsion applicator (e.g., a torsion motor and shaft) configured to apply a torque to a test article that is additively built on and attached to a build plate. The system can include at least one twist sensor and at least one torque sensor. A method for determining quality of an additively manufactured article or batch thereof can include torsion testing at least one additively manufactured test article that is built on and attached to a build plate while the at least one test article is still attached to the build plate.

Abstract: A method for testing rotors is disclosed, wherein a rotor to be tested is coupled in a torque-transmitting manner to an activating motor and is set in rotation. Vibrations of the rotor to be tested are measured, wherein the activating motor is operated such that torsional excitations are generated in the rotor.

Abstract: Embodiments of shaft torque profiling apparatuses and methods of use are generally described herein. In one embodiment, a method for determining the torsional stiffness of a least a portion of a shaft comprises: immobilizing a first portion of the shaft; immobilizing a second portion of the shaft to define a first region between the first portion and the second portion; rotating a first portion of the first region about an axis of the shaft; and measuring a rotation of the first portion of the first region. Other embodiments herein may be described and claimed.

Abstract: A test device comprises a base and a first fixture coupled to the base. The first fixture holds a first portion of an electronic device mounted in the test device. The test device includes a second fixture rotatably coupled to the base and a lever coupled to the second fixture. The second fixture holds a second portion of the electronic device mounted in the test device. The test device also includes an actuator that forcibly moves the lever to rotate the second fixture and apply a torsion stress on the electronic device mounted in the test device. The test device may be used to test the functionality of electronic devices, such as small form-factor disc drives, while under torsion stresses.

Abstract: Embodiments of shaft torque profiling apparatuses and methods of use are generally described herein. In one embodiment, a method for determining the torsional stiffness of a least a portion of a shaft comprises: immobilizing a first portion of the shaft; immobilizing a second portion of the shaft to define a first region between the first portion and the second portion; rotating a first portion of the first region about an axis of the shaft; and measuring a rotation of the first portion of the first region. Other embodiments herein may be described and claimed.

Abstract: A test device comprises a base and a first fixture coupled to the base. The first fixture holds a first portion of an electronic device mounted in the test device. The test device includes a second fixture rotatably coupled to the base and a lever coupled to the second fixture. The second fixture holds a second portion of the electronic device mounted in the test device. The test device also includes an actuator that forcibly moves the lever to rotate the second fixture and apply a torsion stress on the electronic device mounted in the test device. The test device may be used to test the functionality of electronic devices, such as small form-factor disc drives, while under torsion stresses.

Abstract: Apparatus for applying torsional vibration to a rotating machine is provided. In one exemplary embodiment the apparatus includes a permanent magnet machine (12) connected to the rotating machine (22) and configured to generate a three-phase AC output voltage. A converter (36) may be coupled to receive the three-phase AC output voltage from the permanent magnet machine to supply a DC load current. An electrical load (44) (or exciter) may be coupled to the converter to receive the load current. An oscillator (42) is connected to the converter to provide an oscillation signal for modulating the load current from the converter. Modulated load current causes variable loading of the permanent magnet machine thereby creating an oscillatory torque in the permanent magnet machine (12). The oscillatory torque causes torsional vibration in the rotating machine. Various components of the apparatus for applying torsional vibration may be part of a field-deployed power generating system.

Abstract: A multiaxial high cycle fatigue test system for testing bending, torsion, and tension of a test unit, comprises servo-hydraulic components, including a hydraulic service manifold, two small high frequency actuators along a first axis, and one large main actuator along a second axis The large main actuator is used to apply a radial centrifugal force, and the two small actuators are used to apply vibratory loading; the two small side actuators being offset independently of each other, to enable the machine to apply both bending loads and torque to the test unit. The test unit is subjected to torsion loading when the traverse actuators move in phase, that is when both actuators move either in or out at the same time. The test unit is subjected to bending loading when the actuators move out-of-phase, that is one actuator moves in when the other moves out or vice-versa.

Abstract: An apparatus for determining the torsional stiffness of a shaft comprises a rigid frame having a collet for securing one end of the shaft to be measured the rigid frame. A second collet secures the opposite end of the shaft to an inertial weight, which is supported for rotation by a separate bearing so that the inertial weight introduces no axial load in the shaft being measured. The inertial weight has mounted to it a biaxial accelerometer, optical gate or other electronic means for measuring the torsional frequency of the shaft/weight combination. When the inertial weight is displaced from the initial static position and released, the inertial weight oscillates about its center of mass under the urging of the torsional stiffness of the shaft. A computer is programmed with the mass moment of inertia of the inertial weight and therefore is able to solve the differential equation of motion for the torsional spring constant of the shaft based on the frequency of oscillation.

Abstract: An accelerometer includes a bottom leg, two side legs, a beam, two support strips, a mass, a loading column, and at least one resistor mounted on the beam. The two side legs extend upwardly from the bottom leg, and a lower end of each side leg is connected to the bottom leg. The beam is fixed above the bottom leg and between the side legs, and is connected to each of the side legs. The two support strips extend from the side legs toward each other, and the mass is mounted above the beam and connected to the side legs by the support strips. The loading column connects the mass and the beam, such that an acceleration experienced by the mass causes a bending in said beam.

Abstract: According to one aspect of the disclosure, the present invention provides methods and arrangements for testing the integrity of laminate and solder adhesion strength in circuit devices. Methods include securely mounting one end of a circuit device, and affixing a rotatable shaft attached to a controllable servo motor to the other end of the circuit device. The circuit device is monitored so as to be able to detect failure, and torque is applied to the circuit device from the servo motor. When failure of the circuit device is detected, the torque is reduced.

Abstract: A heated unit for testing circuit board assemblies. An insulated enclosure receives card assemblies to be tested through a door. A heater within the enclosure heats the card assemblies at a constant regulated temperature. A motor separately applies angular displacement to the card assemblies which are held in a fixture to stress solder joints between a card substrate and components on the card substrate. The angular displacement is maintained at a predetermined amplitude during tests providing a controlled repeatable stress for the components, which may be repeated between batches of the circuit cards being tested.

Abstract: An apparatus and method provides a testing process and a machine for implementing a testing process to produce failures on a heated circuit card. The apparatus and method applies a controlled, repeatable shear stress to the joints between a circuit board and its mounted components. The circuit board is heated, and one end is twisted with respect to a second end to produce stresses within the circuit board simulating those imposed on components due to thermal cycling. The apparatus may be computer controlled, for regulating the twisting of the circuit board to produce a precise twist angle during a cyclic twisting of the heated circuit board. Electrical resistance of critical joints may be monitored during the testing, and a data base compiled identifying the cycle count at which a failure occurs and location of the failure on the circuit board.

Abstract: A mechanical deflection system (MDS) includes a torsion tester for circuit boards which imposes controlled repeatable sheer stress to a test board and components mounted thereon by cyclicly twisting the board about a center line. A self centering twisting clamp holds one edge of the board and a rotating clamp connected to a backlash free motor and servo mechanism, holds the opposite edge with a limited clamping force. A computer regulates the motor to apply either a specified maximum twist angle or maximum torque, and receives signals from an optical meter which measures the angle, and from a load cell which measures the torque. The computer is connected to detect failures by measuring the electrical resistance of critical joints during testing and it records the location and number of cycles for each failure.

Abstract: A method for non-destructive determination of a fatigue limit for a component includes two sub-methods which may be performed separately, or in any order. A direct-deformation sub-method includes measuring micro-plastic deformation corresponding to each of a plurality of different known values of stress applied to the component, and identifying a critical value of stress corresponding to a change in the relationship between stress and micro-plastic deformation. An internal-friction damping method includes initiating torsional oscillations in the component, measuring an initial angular amplitude of oscillation, A.sub.0, and a final angular amplitude of oscillation, A.sub.n at the end of the number, n, of oscillations. This process is repeated a number of times and, for each pair of measurements, a corresponding measure of damping is calculated. A critical value of initial angular amplitude corresponding to a change in the relationship between amplitude and damping is then calculated.

Abstract: A mechanical deflection system (MDS) includes a torsion tester for circuit boards which imposes controlled repeatable sheer stress to a test board and components mounted thereon by cyclicly twisting the board about a center line. A self centering twisting clamp holds one edge of the board and a rotating clamp connected to a backlash free motor and servo mechanism, holds the opposite edge with a limited clamping force. A computer regulates the motor to apply either a specified maximum twist angle or maximum torque, and receives signals from an optical meter which measures the angle, and from a load cell which measures the torque. The computer is connected to detect failures by measuring the electrical resistance of critical joints during testing and it records the location and number of cycles for each failure.

Abstract: A method for measuring the torsional rigidity distribution of a shaft comprises the steps of; disposing a shaft to be measured in a vertical position in which the upper end thereof is immovably held and the lower end of the shaft is rotatable about the axis of the shaft, demarcating the shaft along its length so as to establish a number of discrete sections of the shaft, performing measurements of the torsional frequency of an inertial mass held at designated discrete positions shaft, and calculating the torsional rigidity of each discrete section based on the measured torsional frequencies.

Abstract: A torsion tester for circuit board assemblies (boards) clamps opposite edges of the board and cyclicly twists the board to provide substantially pure sheer stress in interconnection joints to SMT components for replicating failure modes due to thermal cycling. The boards are automatically centered in the clamps, the distance between the clamps is automatically measured, and the machine rotates one of the clamps to produce out-of-plane deflection which repeat within 0.01 degree per inch of the distance to provide repeatable results. During testing the maximum deflection and torque of each cycle and the location and cycle count at each failure is automatically recorded until a large population of failures is obtained. The population of failures is automatically compared to a statistical database of previous populations to identify any unusual deviations and for determining the reliability of the production process.

Abstract: A device for measuring a force, a pressure or a torque transmitted in a force path between first and second apparatus components, includes at least three mutually spaced piezo-resistive resistor elements disposed in the force path between the first and second apparatus components such that the apparatus components orthogonally stress the resistor elements.

Abstract: A method for tightening a screw utilizes a power-impact or pulse driver. The prestressing force in the screw to be tightened is increased step-by-step during the tightening operation and evaluated. By detecting the prestressing force in the screw on a step-by-step basis, the step heights pertaining to the increase in the prestressing force and the change in the step heights are used as criteria for the screw-coupling quality and for controlling the screw-coupling operation. In the same way, the number of impacts or pulses is also used as a criterion for the screw-coupling quality and for controlling the screw-coupling operation.

Abstract: An apparatus and method for measuring interface properties of a composite test specimen includes a first jaw for gripping the specimen. The specimen has a fiber extending through a matrix forming a fiber-matrix interface with a portion of the fiber extending from the matrix. A second jaw grips the fiber extending from the matrix. A motor drive coupled to the first jaw rotates the fiber relative to the matrix. The torque transmitted through the fiber-matrix interface to the fiber is measured with a stationary torque transducer coupled to the second jaw with respect to the angular rotation of the fiber relative to the matrix. From the resulting torque-twist angle plot, composite interface properties such as interfacial fracture energy and frictional traction can be obtained.

Abstract: A process and an apparatus for testing stabilizers (10) which are supported on stationary bearings (16, 17) upon a bench (32) and which are strained via a drive assembly by movement of one stabilizer leg (12) against the other stabilizer leg (13) includes mass elements (18, 19) attached to stabilizer legs (12, 13), the mass elements (18, 19) being movable via the oscillator exciter (27) attached to one side of the mass element (18) in a manner such that the mass-spring system formed by the stabilizer (10) and mass elements (18, 19) oscillates at its resonant frequency.

Abstract: An apparatus for producing predetermined torsional vibrations in a mechanical transmission is disclosed. The apparatus includes a summing gear arrangement including a non-revolving gear member such as of a planetary or differential gear assembly. The summing gear arrangement includes at least three shafts or three gears wherein the non-revolving gear member is rotatably mounted and is connected to a control capable of transmitting impulses corresponding to the torsional vibrations. The summing gear arrangement combines the torsional vibrations with a mechanical input thereto to produce an altered output.

Abstract: An exciter is disclosed for applying a dynamic torsional force to a rotating structure, such as to the shaft of a turbine generator, the axle of a vehicle, or the like, during mechanical testing to determine the mechanical response characteristics, natural modes of vibration, fatigue life, etc., of the structure. The exciter includes a rotary hydraulic actuator having a housing secured to the structure to be tested and a driveshaft which is rotatable relative to the housing as well as an inertial mass mounted on the driveshaft.