Abstract: Methods for real-time coiled tubing fatigue monitoring can establish a remaining operational life of a coiled tubing strand. Standard or low-cycle plastic fatigue in bending is measured each time the coiled tubing strand is deployed through a guide arch. Also, smaller, but higher frequency loads, e.g., high cycle loads imparted to the coiled tubing strand due to interaction with an oceanic environment, are also measured. A plurality of weight detectors may be coupled to a support frame below the guide for monitoring the high-cycle loads. The remaining operational life of the coiled tubing strand may be calculated based on both the plastic strains using a low-cycle fatigue analysis and the elastic strains using a high-cycle fatigue analysis. An operator may retire a coiled tubing strand prior to failure based on the calculated remaining operational life.

Abstract: An apparatus for fatigue and/or crack growth testing, including a cyclic loading device and a preferred sample mounted at one end. An embodiment of the device has at least two concentric and coaxial load frames, with guiding interfaces between adjacent load frames to maintain alignment. Solid state actuation systems, which deform in response to the application of energy, are mounted at the end opposite the sample between adjacent load frames to provide up to two modes of actuation, including tension, compression, or torsion. The preferred sample includes a cylindrical gage section with a concentric hole running from a first end, and terminating within the gage section, with one mode of loading introduced at the terminus of the hole, and reacted at the end where the hole originates. A second mode of loading is optionally introduced at a second end of the specimen. Mount hardware for conventional specimens is also presented.

Abstract: A control system is disclosed for controlling a mechanical test comprising a flow control valve that controls a fluidic mechanical muscle having a sheath and a bladder disposed within the sheath, and a servo-controller that controls the operation of the flow control valve based on an output signal from a master controller based on an input signal corresponding to a desired test profile. A method of controlling a component test is disclosed comprising the steps of programming a test profile in a logic controller, supplying a signal to a master controller, supplying a signal from the master controller to a servo-controller, and controlling the flow of a fluid into a fluidic mechanical muscle having a sheath and a bladder disposed within the sheath for applying and reducing mechanical loads on a test specimen.

Abstract: The invention is a device for dynamically load testing a sample that comprises a bearing, to which the sample can be directly or indirectly connected in a detachable manner, as well as a counter-bearing that can be effectively connected to the sample by means of at least one actuator element. The at least one actuator element introduces dynamic mechanical loads into the sample which Act along a load path that is directed between the bearing and the counter-bearing and extends through the sample. The at least one actuator element features a multifunctional solid body conversion material system that undergoes deformations due to the supply of energy, and wherein the deformations are at least one cause for the mechanical loads occurring within the sample. The device according to the invention uses at least one actuator element that may be configured in two alternative forms.

Abstract: A control system is disclosed for controlling a mechanical test comprising a flow control valve that controls a fluidic mechanical muscle having a sheath and a bladder disposed within the sheath, and a servo-controller that controls the operation of the flow control valve based on an output signal from a master controller based on an input signal corresponding to a desired test profile. A method of controlling a component test is disclosed comprising the steps of programming a test profile in a logic controller, supplying a signal to a master controller, supplying a signal from the master controller to a servo-controller, and controlling the flow of a fluid into a fluidic mechanical muscle having a sheath and a bladder disposed within the sheath for applying and reducing mechanical loads on a test specimen.

Abstract: A coupon fabrication with defined distortion in the form of marceled fibers and test protocol is employed to determine the shape of the failure probability density curve to improve the analyses of the risk of fiber distortion anomalies in composite structures. This protocol provides a method to determine the probability of and the severity of the various distorted fiber conditions that might exist on composite structure in fabrication and in service. A distortion characterization matrix is established for determining test shapes and providing defect characterization based on the results of tests on the selected shapes. Coupons for test are created using resin pool.

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 method of simulating life of a rotor blade mounting feature mounted in a complementary rotor disc mounting feature comprises the steps of providing two specimen mounting features (37) each having portions defining pressure faces matching in profile respective faces of the rotor blade mounting feature; providing a fixture (38) having two opposed mounting features (39) each having portions defining pressure faces (78) matching in profile respective faces of the rotor disc mounting feature; mounting the specimen mounting features (37) in the fixture mounting features (39); applying a first load to the specimen mounting features (37); measuring a strain in a region (86) of the fixture (38) between the fixture mounting features (39); applying a second load to the fixture (38), the second load being substantially perpendicular to the first load; and controlling the second load in response to the measured strain. A high cycle load may simultaneously be applied to the specimen mounting features (37).

Abstract: A thread wear gauge for coil threads. Coil threads have a nominal new thread profile that offers a substantial load bearing area. The thread wear gauge has a gauging thread with a silhouette that permits it to threadably engage with a coil thread that has been worn so that the shear load bearing area of the thread has been worn away from the coil thread to the point where the coil thread is unsafe for further use. The gauging thread will not threadably engage with the coil thread if the load bearing area has been worn to the point where it is unsafe. The thread wear gauge is a simple, reliable, hand held tool that is capable of being used under field conditions. In use, the thread wear gauge is grasped and manipulated with one hand. An attempt is made to threadably engage the gauging thread on the thread wear gauge with the coil thread that is to be tested. The operator observes whether the gauging thread threadably engages with the coil thread. If it does engage, use of the coil thread is discontinued.

Abstract: A test method for testing the thermal mechanical fatigue performance of a test material includes preparing a test specimen of the test material, wherein the test specimen has a base, and a rib extending outwardly from the base. The test specimen is thermally cycled through at least one test cycle. In each test cycle the rib is heated to a higher rib temperature and thereafter cooled to a lower rib temperature. The test specimen is evaluated for thermal mechanical fatigue damage.

Abstract: A thread wear gauge for coil threads. Coil threads have a nominal new thread profile that offers a substantial load bearing area. The thread wear gauge has a gauging thread with a silhouette that permits it to threadably engage with a coil thread that has been worn so that the shear load bearing area of the thread has been worn away from the coil thread to the point where the coil thread is unsafe for further use. The gauging thread will not threadably engage with the coil thread if the load bearing area has been worn to the point where it is unsafe. The thread wear gauge is a simple, reliable, hand held tool that is capable of being used under field conditions. In use, the thread wear gauge is grasped and manipulated with one hand. An attempt is made to threadably engage the gauging thread on the thread wear gauge with the coil thread that is to be tested. The operator observes whether the gauging thread threadably engages with the coil thread. If it does engage, use of the coil thread is discontinued.

Abstract: The present invention, in certain embodiments, discloses an apparatus for determining characteristics of coiled tubing that is run in and out of a bore, e.g. a wellbore, for calculating fatigue life of the coiled tubing, the apparatus having a reel structure for said coiled tubing including a reel on which said coiled tubing is wound and a frame supporting the reel for rotation, an injector structure for running the coiled tubing from the reel structure into said bore and for withdrawing said coiled tubing from the bore, sensor apparatus for continuously monitoring sensing and recording rotation of said coiled tubing and for measuring amount of said rotation, said sensor apparatus including apparatus for receiving and transmitting data relating to said characteristics of the coiled tubing, and a computer apparatus for receiving data from said sensor apparatus and processing said data to determine fatigue life of said coiled tubing.

Abstract: The present invention is a novel electronic technique that detects stress/strain in any conductive or semiconductive material. The technique is based on passing a current through the material of interest and analyzing the low frequency voltage fluctuation. The voltage fluctuation is very sensitive to the amount of stress present in the sample. The voltage fluctuation is a result of interactions between the imposed current and material itself. The technique is many orders of magnitude more sensitive than any present method. The technique is suitable for sensitive measurements without a strain gauge. The technique is not limited by sample size, and provides a simple, fast, nondestructive and on-site evaluation of stress/strain in a material.

Abstract: A monitoring system for detecting failures, or impending failures, in subsystems of a fly-by-wire primary flight control system of an aircraft. The system monitor a critical variable of at least two controllers acting in concert, in real time. Differences between the critical variables are calculated and, after filtering to remove insignificant variations, structural fatigue damage is estimated based on significant detected variations. Depending upon the relative severity of the estimated fatigue damage, the aircraft's primary flight control computer is programmed to shut down the malfunctioning subsystem, display a message indicating need for repair, or take other appropriate action.

Abstract: A process is provided for the adaptive actual-value correction during fatigue strength tests in which a deviation of the actual value from the desired value is determined and by means of a change of the desired-value indication to a desired correction value, the actual value can be controlled in the direction of the real desired value.

Abstract: A mechanical test system is provided comprising a primary actuator arranged so as to create mechanical movement of a first specimen holder along an axis of actuation and an oppositely oriented secondary actuator arranged so as to create mechanical movement of a second specimen holder along the axis of actuation. The magnetostrictive actuator comprises a magnetostrictive assembly including a magnetostrictive element and a flexible disk mechanically coupled to the magnetostrictive element. The magnetostrictive element comprises either a magnetostrictive material portion with a plurality of cooling fluid bores formed within the magnetostrictive material portion or an epoxy matrix with a plurality of cooling fluid bores and a plurality of magnetostrictive rods formed within the epoxy matrix.

Abstract: A test assembly suitable for life testing a computer pointing stick includes a rigid shaft that is rotated by a motor and a mounting mechanism for holding and positioning the pointing stick under test in a coaxial relationship with the rigid shaft. A cantilever spring arm is rigidly connected at one end to the rigid shaft so that it rotates with the rigid shaft and is mechanically coupled under lateral spring tension at its other end to the pointing stick. The spring rotates with the rigid shaft and applies lateral force to the pointing stick via a collar attached to the pointing stick, the direction of the applied force rotating with the rigid shaft and cantilever spring. A counter records the cumulative number of flexure cycles required to make the pointing stick functionally fail.

Abstract: The fatigue integrity of metallic materials may be determined by either one of two methods. In a first method, an impulse of energy is introduced into the metallic material, such as by striking the metallic material, and the induced vibration is sensed and analyzed in order to compute the damping factor thereof, the damping factor being directly related to the fatigue thereof. With this method, a transducer is coupled to the metallic material and its output is amplified by an amplifier before input to a computer which determines the damping factor. In a second method, a continuous energy input is provided to the metallic material, such as by utilizing a frequency generator coupled to a power amplifier whose output drives a transducer such as a speaker or the like for inducing a continuous vibration in the metallic material. This continuous vibration is measured with a transducer, an amplifier, and a damping factor calculated with a computer as in the first method.

Abstract: The magnetoelectric coefficient in iron-based alloys has a stress value of about 0.6 of that of the elastic limit. A reversal in sign is caused by structural phase slip which is the basis for the onset of metal fatigue. Based on this phenomenon, a method is provided for determining the onset of metal fatigue. The method includes applying a periodic mechanical stimulus at a given frequency to a test structure, and using a magnetometer, sensing the magnetic field of said structural element during the application of stimulus, and then determining whether or not there is a 180 degree difference between the phase of the stimulus and that of the magnetic response for various regions of the test structure.

Abstract: An apparatus and method for force-controlled fatigue testing of a specimen or material. A driver is used to generate a load force which is applied to the test specimen. Physical property changes of the test specimen are measured over time and a feedback signal is generated as a function of the measured physical property changes. A motion command signal is computed as a function of the feedback signal. A computer processes the feedback signal and emits the motion command signal to an actuator. The driver responds to the motion command signal and maintains the load force at an approximately constant magnitude during the physical property changes of the test specimen.

Abstract: Apparatus for applying an optimal tension exceeding alternating forces to a specimen being measured by automatically detecting saturation of a relaxation phenomenon that has occurred in the specimen when the dynamic viscoelasticity of the specimen is measured by a tension method. The apparatus includes a strain detector for detecting changes in length of the specimen, an electromagnetic force generator for applying a force to the specimen, a moving mechanism for moving the electromagnetic force generator, a movement control unit for controlling the amount of movement of the drive mechanism, a strain differentiation circuit for differentiating the output of the strain detector, and a comparator for comparing the output of the strain differentiation circuit with a target differential value and producing a tension control timing signal.

Abstract: A tension type dynamic viscoelasticity measuring apparatus composed of a strain detector for detecting changes in length of a specimen, an electromagnetic force generator for applying a force to the specimen, a moving mechanism for moving the electromagnetic force generator, a movement control unit for controlling the amount of movement of the moving mechanism, and a monotone function calculation unit for outputting a movement control timing to the movement control unit. The monotone function calculation unit performs a monotone function operation on the data of distance by which the moving mechanism has been moved and uses the calculation result as a movement control timing for the next movement control of the moving mechanism. As a result, this viscoelasticity measuring apparatus has a movement control loop that considers relaxation phenomena in connection with a change in length of the specimen due to stress relaxation and creep that occur in the specimen while driving the moving mechanism.

Abstract: A cyclic fatigue testing apparatus intended for testing the cyclic fatigue of samples such as ceramic or the like, in which it comprises a vibration plate assembly comprising a flex plate provided with piezoelectric element layer(s) on at least one surface thereof, a sample supporting member disposed on the vibration plate for supporting the sample and a loading member for forcing the samnple onto the supporting member. The apparatus can operate over a wide frequency range by adjusting the position of the sample supporting member with respect to the flex plate and selecting the frequency of an alternating voltage to be applied to each piezoelectric element layer.

Abstract: A non-destructive testing device and method is provided wherein a test piece is held in a test stand located in a test enclosure. The test enclosure is evacuated. The test stand and test piece held therein is then vibrated, immediately after which the test piece is irradiated by at least one beam of collimated radiant energy, preferably ultraviolet light, which is scanned over the test piece in a systematic pattern. Measurements of exo-electrons given off by the test piece responsive to the irradiation of the test piece are recorded for correlation with other exo-electron measurements made of the test piece throughout the life of the test piece. For metal test pieces not sensitive to this technique, a selected gas or gases (mixed or in sequence) may be introduced into the evacuated chamber for forming a surface compound of gas and metal on the surfaces of the test piece. The test enclosure is then evacuated and the test piece is vibrated and scanned by radiant energy and measurements taken.

Abstract: The invention provides a method of stress grading timber, and a timber stress grading machine. The method and machine involve continuously moving a length of timber and stressing the moving length by applying a transverse load thereto. The length is supported by two supports between which the load is applied and the load causes a deflection of the timber length. The load and/or deflection are measured and the moving length is stressed differently by thereafter applying a different load to the timber length at the same position while supported in the same fashion to obtain a different deflection. The different load and/or deflection are measured and the original load and original deflection are related to the different load and different deflection according to predetermined criteria, thereby to grade the timber length. The machine provides means for carrying out the method.