Abstract: Provided is an exciter device for fatigue testing of a blade of a wind turbine, including a actuator for generating a periodic excitation force and a coupling device for coupling the actuator to a blade to be tested. The exciter device includes a pretensioning device applying a pretension such that the excitation force only acts in a pulling or pushing direction over the whole period.

Abstract: Electromagnetic transient simulation method applicable to a field programmable gate array (FPGA), which integrates topological parameters of a circuit to be simulated into two matrix parameters in an initialization stage thereof; and voltage and current information at each simulation moment can be obtained only through simple matrix multiplication operation in a main part of the simulation cycle thereof. The method avoids complex initialization operation in the field programmable logic array; meanwhile, the flow of the main part of the simulation cycle in the FPGA is maximally compressed, and the efficiency of electromagnetic transient simulation based on the FPGA is greatly improved.

Abstract: A sensor apparatus is provided. Multiple opposite and self-powered sensors are provided in another aspect of the present apparatus. A further aspect employs a sensor apparatus including a first pair of flexible piezoelectric sensors attached to opposite sides of an exterior surface of a workpiece and at least a second pair of flexible piezoelectric sensors attached to opposite sides of the exterior surface of the workpiece. Another aspect of the present apparatus uses pairs of thin film piezoelectric sensors which are configured to detect bending curvature of a workpiece in at least two dimensions by sending voltage output signals from both of the sensors of a first pair and/or both of the sensors of at least a second pair to a controller and/or electrical circuit.

Abstract: In a case where control input is performed via a low-pass filter, a control gain more appropriate for both stability and responsiveness is set according to setting of the low-pass filter. A control unit (21) performs control input for a load mechanism (40) via a low-pass filter, discriminates a stability of a control system including the load mechanism (40) and the low-pass filter when setting of the low-pass filter is changed, sets an appropriate control gain based on a maximum control gain at which an excess amount of a measured value with respect to a target value is equal to or less than a predetermined value within a range where that the control system is stable, and controls an operation of the load mechanism (40) by using the appropriate control gain.

Abstract: Described herein is a method and system for testing a force or strain sensor in a continuous fashion. The method employs a sensor, a test fixture, a load cell, a mechanical actuator and tester hardware and software to simultaneously record signal outputs from the sensor and load cell as functions of time. The method provides time synchronization events for recording data streams between, for example, a linear ramp of the force on, or displacement of, the sensor and for extracting performance characteristics from the data in post-test processing.

Abstract: Provided is a method and an arrangement of fatigue testing of a wind turbine rotor blade, the method including: operating an actuator attached to the rotor blade, thereby moving a mass connected to the actuator in a reciprocating manner. The mass may be a hanging mass, for example, hanging down from the actuator.

Abstract: A method for protecting an electric machine of a motor vehicle, In the method, a switch-on frequency for the electric machine is ascertained as a function of operating parameters of the motor vehicle stored in a control unit. The switch-on frequency is compared to a predefinable first threshold value. At least one further threshold value is preset. The electric machine is switched on in the event a control variance exceeds the at least one further threshold value. In the event the switch-on frequency exceeds the first predefinable threshold value, the at least one further threshold value is adapted in such a way that the switch-on frequency of the electric machine is limited.

Abstract: 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.

Abstract: A monitoring device and a method for determining operating health of a pressure medium operated device. The monitoring device is configured for processing input measuring data relating to operation of the pressure medium operated device. An operating condition value is determined in the monitoring device, where after the operating condition value is compared to an input reference data in order to determine current operating health. The reference data is determined by utilizing strength analysis, which is executed for a design model of the associated pressure medium operated device.

Abstract: A method for testing and extracting paleo-tectonic geostress based on rock core, including: selecting rock cores in different tectonic periods; preparing standard cylindrical samples from the rock cores in a specific orientation; subjecting the samples to an acoustic emission test to test paleo-stresses of multiple tectonic periods and obtain paleo-tectonic stress data sequence; based on a correlation analysis and an Euclidean distance of the stress data sequence, stripping and extracting multi-level Kaiser stress points of the acoustic emission of rock cores from different formations, so as to calculate and evaluate the ground stress of an evaluated formation in an evaluated paleo-tectonic period.

Abstract: The present invention belongs to the technical field of mechanical test devices, and provides a multi-bolt loosening test machine for flange with tension and bending compound loading, which is a test machine researching the anti-looseness properties of bolts by applying tension, bending and torsion compound loading to multi-bolt connection flanges. The multi-bolt loosening test machine for flange with tension and bending compound loading uses a transverse load generated by a three-phase asynchronous motor as a bending load applied to a flange, uses a tension force generated by a hydraulic puller as an axial tension load, is different from the current device that can apply two compound loads to a single bolt, and can apply two compound loads to the multi-bolt connection flanges. The present invention can isolate two compound loads from each other without interference, and display the applied loads in real time.

Abstract: The present invention provides a multi-bolt loosening test machine for flange with tension, bending and torsion compound loading. The multi-bolt loosening test machine for flange with tension, bending and torsion compound loading uses a transverse load generated by a three-phase asynchronous motor as a bending load applied to a flange, uses a tension force generated by a hydraulic puller as an axial tension load, and uses a torque generated by a servo motor as a torque load applied to the flange. The test machine is different from the current device that can apply two compound loads to a single bolt, and can apply three compound loads to the multi-bolt connection flanges. The present invention can isolate three compound loads from each other without interference, and display the applied loads in real time.

Abstract: The present invention relates to a holder having an actuation unit, particularly as a part of a material testing machine for testing specimens, for example metal test-specimens, which are held at high forces that are particularly due to the type of testing. The actuation unit operates with pressure from a pressure source. A bi-stable fluid control valve is temporarily in a first or in a second state, in particular depending on pressures at actuation sides of the valve. Besides a first actuator, which is responsible for the regular clamping force of the clamping face, to a second actuator is provided. The second actuator may also be referred to as motion unit due to its motion force to the clamping piston. The actuators arrange for a certain de-coupling of the different forces when holding and clamping specimens. Such a circuit offers the desired safety degree.

Abstract: An apparatus and method of testing are provided to test the durability and resilience of crib mattresses and other child development surfaces. The testing apparatus is configured to provide a movable fixture for imparting repeated force to a mattress. The fixture can include a pair of feet formed thereon to mimic the pressure profile provided by a toddler standing or jumping on a crib mattress. The method provides for the cycling of the apparatus over a predetermined time period and the determination of the deflection of the surface after the time period.

Abstract: A fixture facilitates using a linear force of a uni-axial test machine to subject a test sample to bending forces. The test machine includes a frame and a crosshead. To generate the linear force, the crosshead translates with reference to the frame in a plane of motion. The fixture includes an upper connecting link, a lower connecting link, and two transverse arms. The upper connecting link is configured to attach to the crosshead for receiving the linear force, and the lower connecting link is configured to attach to the frame. The two transverse arms are pivotably carried between the upper and lower links. Each transverse arm has an inner end configured to attach to the test sample, the test sample being suspended between the arms. The transverse arms pivot in opposite directions in response to the linear force applied to the upper connecting link, exposing the sample to bending forces.

Abstract: A system (1100) for fatigue testing wind turbine blades (1102) through forced or resonant excitation of the base (1104) of a blade (1102). The system (1100) includes a test stand (1112) and a restoring spring assembly (1120) mounted on the test stand (1112). The restoring spring assembly (1120) includes a primary spring element (1124) that extends outward from the test stand (1112) to a blade mounting plate (1130) configured to receive a base (1104) of blade (1102). During fatigue testing, a supported base (1104) of a blade (1102) may be pivotally mounted to the test stand (1112) via the restoring spring assembly (1120). The system (1100) may include an excitation input assembly (1140) that is interconnected with the blade mounting plate (1130) to selectively apply flapwise, edgewise, and/or pitch excitation forces.

Abstract: Apparatus for fatigue or mechanical friction damping measurement testing a specimen the apparatus including a body having opposing arms defining between them a space for receiving the specimen, one of the opposing arms having a fixture for securing the specimen, another of the opposing arms having a further fixture for securing the specimen, the fixture and the further fixture being adjustable to increase or decrease the relative distance therebetween, wherein the body includes an assigned vibration location to which excitation signals are applied during testing.

Abstract: A monitoring system is provided, which may include a structural component configured to undergo mechanical loading and a wireless node attached to the structural component. The node may include a strain sensing device configured to measure strain experienced by the structural component at the location of the node. The node may also include a processor configured to predict, based on the strain measurements, fatigue life of the structural component.

Abstract: A method of evaluating the condition of a rolling burnishing element includes moving a burnishing element having an unknown condition against a surface in a preselected test pattern; while moving the burnishing element, recording at least one test force profile representative of a force acting on the burnishing element in at least one dimension; and comparing the at least one test force profile to at least one baseline force profile to determine a deviation of the condition of the second burnishing element from a baseline condition.

Abstract: A method of evaluating the condition of a rolling burnishing element includes moving a burnishing element having an unknown condition against a surface in a preselected test pattern; while moving the burnishing element, recording at least one test force profile representative of a force acting on the burnishing element in at least one dimension; and comparing the at least one test force profile to at least one baseline force profile to determine a deviation of the condition of the second burnishing element from a baseline condition.

Abstract: A method and method of estimating fatigue life of a structure is disclosed. In one embodiment, the method may include determining strain on the structure using a plurality of gauges positioned on the structure. The method may also include detecting a parameter of the structure with a plurality of sensors positioned on the structure. Further, the method includes converting the detected parameter and the determined strain to proportional loads acting on the structure and transforming the proportional loads to coordinate system data associated with the structure. Based on the coordinate system data, the fatigue life of the structure may be estimated.

Abstract: An apparatus and method for measuring the fatigue strength and fatigue damage of structures and predicting the service life remaining in the structure being tested. The apparatus is a specially designed fatigue gauge that contains breakable ligaments of either variable length to measure fatigue strength or fatigue damage of metallic, polymeric and composite materials or the same length but different composition to measure the fatigue strength and fatigue damage of certain composite materials.

Abstract: The invention involves an apparatus and method for calculating characteristics of materials, such as equivalent strain, using an indenter where the method used is independent of indenter geometry. The method includes performing a scratch test to calculate the strain for each of a plurality of indenter shapes, such as a theoretical sphere and cone, using known equations. The strain of a composite indenter, such as a cone with a rounded tip, can then be determined taking into account contributions from each of the plurality of theoretical shapes.

Abstract: The invention includes an apparatus and method for determining the pass through flux of magnetic materials. The apparatus comprises one or more magnetic field sensors arranged in such a way as to collect field strength data in any or all the x, y, z directions. The apparatus also comprises a magnet field source or arrangement of magnet field sources which are placed beneath the material being characterized and includes a mechanism whereby the magnetic material can be mapped by the movement of any one or combination of: magnetic field source or sources, sensors and magnetic material. The invented method comprises the use of various configurations of magnetic sources in order to generate a magnetic field that emulates the open-loop condition found in magnetron sputtering.

Abstract: A simulation apparatus is provided comprising a fixed main body; a carriage associated with the main body for movement relative to the main body; a first device coupled to the fixed main body for engaging a workpiece; a second device coupled to the carriage for movement with the carriage and for engaging the workpiece; at least one motor apparatus coupled to the fixed main body and the carriage for effecting movement of the carriage and the second device relative to the main body such that a tensile load is applied to the workpiece; sensor apparatus comprising at least one force sensor for sensing the tensile load applied to the workpiece during the movement of the second device; and a drive controller.

Abstract: A pole support for ground poles, such as telephone poles and power poles, is disclosed. The support can be driven into the ground next to the pole. It has a pair of spaced apart longitudinal end plates which are interconnected intermediate their ends by an intermediate plate. The end plates are spaced apart to allow the ground pole to pass at least partially between the end plates. Each end plate has a front longitudinal edge which, in use, is adjacent to the pole and a rear longitudinal edge which, in use, is directed away from the pole. The pole support has means to reduce sharp edges on the rear longitudinal edges. Also disclosed is a method for testing pole strength which comprises applying a load to the pole and either measuring its displacement or observing if it withstands the load. The amount of load applied to the pole and the degree of displacement is undergoes can be used to calculate the residual strength of the pole.

Abstract: The present invention relates to a method of calculating the pressure drops created by a given fluid in a circuit having a determined thermal profile. The method includes making up a database (BD) giving the rheology of various fluids at least according to the temperature; segmenting a thermal profile (2, 3) into sections (4, 5, 6, 7) and determining a representative temperature value (T1, T2, T3, T4) for the fluid in each section; using the database for determining the rheology of the fluid in each section at the representative temperature; and calculating and adding up the pressure drops in each section considering the rheology determined.

Abstract: A strain testing apparatus which places tensile forces on a sheet, a film, or the like samples in at least two axes and generally in a radial direction. The multi-axial strain testing apparatus comprises a clamping assembly having at least two clamping members, and a sample securing portion arranged in a substantially radial manner about a point. The multi-axial strain testing apparatus can advantageously be employed to test crack growth propagation and flex fatigue in rubber polymer and elastomer samples.

Abstract: There is disclosed a method and apparatus for testing the static load-bearing capacity of a pile, wherein a test load is applied to the top of the pile (2) by way of a jack (1) braced against a reaction member (3) and the magnitude of the test load and the resulting displacement of the pile are measured and communicated to an electronic computer (7). The electronic computer (7) issues control signals to the jack (1) in response to the measured magnitude of the test load so as to apply a predetermined regime of test loads to the top of the pile (2). By automatically monitoring the applied test load, it is possible to maintain a desired load with a high level of accuracy for an extended period of time without the need for operator intervention.

Abstract: A material testing machine includes a control system for feedback-controlling the operation of a servo system, including an actuator for applying a load to a test piece, during material testing. Prior to the material testing, the stiffness of the test piece is estimated on the basis of the actual load and displacement which are detected after the displacement of the test piece is stabilized while maintaining the load observed when a minute displacement is generated in the test piece as the control gain is increased from its minimum value. In accordance with the estimated stiffness, the initial value of the control gain for the control system is set. During the material testing, the control gain is corrected in accordance with the stiffness of the test piece estimated based on the actual load and displacement of the test piece.

Abstract: A method for measuring permanent length deformations in materials includes determining a change of an initial distance between two measuring points on the material surface. A first pair of impressions is formed on a portable impression body that corresponds to these two measuring points prior to the expected deformation and a second pair of impressions is formed after a critical loading of the material. The distances between the first and the second pairs of impressions are then compared. A device for carrying out the method uses a fixed portion arranged on the material being measured and a portable impression body. The fixed portion of the device is provided with a pair of measuring elements which correspond to the measuring points disposed at a mutual distance from each other, and the portable impression body of the device has an impression face adapted for receiving the impressions that are created by the measuring elements.

Abstract: The invention is a machine for the cyclic load testing in tension, compression, torsion, shear, or any combination thereof of any one of a number of different sizes, types and configurations of test specimens at a fixed or adjustable predetermined load and cycle rate and comprising a machine frame in which is mounted a drive shaft, any number of intermediate shafts as required, and a camshaft or crankshaft. At the workstation of the machine, appropriate fixtures and tooling are either fixed, rotating, or in motion, as required to conduct the particular test to be performed. When the test specimen is to be in motion, the motion may be derived from a driving source separate from the primary mover or camshaft, for instance but not limited to an independent motor or cylinder. This source of motion may also be taken through a drive train or any suitable means from the same driving source as the camshaft or from the camshaft itself or from any other moving member in the system.

Abstract: Method and apparatus for simulating operating conditions on a motor operated valve. The present invention provides a means for simulating actual operating load conditions, such as a simulated accident condition, for valves. An axial force is placed on the valve stem by a hydraulically operating loading system to simulate loading conditions associated with a postulated accident, and the valve operator is actuated. The response of the valve during the simulated loading condition is monitored to ensure that the valve is capable of operating, such as to close or open, in the event of an unusual condition.

Abstract: In the field of large construction and mining equipment, significant frame stresses considerably shorten the expected operating life of a machine. This invention provides indications of significant frame stresses on machines having a ground engaging portion, a frame connected to the ground engaging portion, and a plurality of pressure sensing devices. Each of the pressure sensing devices are adapted to produce pressure signals indicative of loads imparted on the frame. The pressure signals are processed to produce frame stress data.

Abstract: A structure testing machine for carrying out tests on a test structure (25) for an assessment of the response of the structure to test loads applied to the structure in the direction of a predetermined axis of the structure under the control of a monitored control system (21) which forms part of the machine and which has a forward path which includes an actuator (24) which is supported by a machine frame and which upon actuation applies to the test structure a test load in the direction of the predetermined axis, and a controller (22) responsive to a controller input signal and to controller parameters to apply to the actuator an actuating signal to cause the actuator to subject the test structure to a test load which produces dimensional changes in the test structure in the direction of the predetermined axis. The machine is provided with an adaptive control loop which comprises a stiffness estimator (27) which generates from the dimensional changes in the test structure adaptive control signals (E.sub.

Abstract: A flywheel tensile testing apparatus for viscoelastic materials is used for high-rate tensile testing to determine the mechanical properties such as the initial modulus, the stress-strain characteristics, energy at break, and void formation of energetic materials such as solid propellants and plastic bonded explosives under deformation rates in excess of 20,000 inches per minute. The tensile tester is comprised of a plurality of support trestles which are mounted on a common base. A flywheel and a light weight engagement wheel are mounted for rotation on the support trestles. A clutch and rotor assembly is located between the flywheel and the light weight engagement wheel so that when the clutch is engaged, the stored energy of the flywheel is transferred to a rotor assembly which in turn drives the light weight engagement wheel. The flywheel is driven by a variable speed motor. The activation of the clutch and rotor assembly are preferably performed in response to an electronic signal.

Abstract: Stress in a substance is measured by utilizing the transfer characteristics of elastic waves, such that elastic waves input to a substance are displaced by the stress load within the substance. Waves input to the substance and output therefrom by transmission or reflection are compared by fast fourier transform analysis, obtaining a wave attenuation factor quantifying the magnitude of stress in the substance.

Abstract: Disclosed is a testing machine for testing specimens such as lumber which may have varying overall lengths. The testing machine includes the frame having an elongated longitudinal member which can be pivotally mounted with respect to stands. Two sets of transverse arms are connected to the longitudinal member at appropriate points. One set of transverse arms is pivotable. The transverse arms extend outwardly from the longitudinal member and have an extendible and contractible force member for increasing and decreasing the distance between the arms along one side of the frame. Jaw sets are pivotally mounted to the transverse arms opposite from the force member for engaging a specimen being tested. The jaw sets are preferably hydraulically closed, using the same hydraulic supply as used to extend the force member, thus automatically proportioning the gripping force of the jaws with relationship to the applied load to the specimen.

Abstract: A railroad side frame test machine for loading side frames used on the trucks or carriages for railway cars to simulate the in-use loads utilizing a compact linkage that provides for direct loading of the specimen in the various load directions. The forces are applied to the specimen to insure that certain reactions are grounded, while other applied forces are basically ungrounded to effectively eliminate "cross talk" between the various input loads or forces.

Abstract: A system for measuring or testing the firmness of a resilient object such as a mattress. A pressure applying platen or the like is driven by a motor into the object, and the pressure applied is measured through the utilization of a pressure sensitive transducer or the like. This generates electrical power proportional to the pressure, and a recorder displays information to provide a reading of the power generated. The generating means is also connected to control means for the motor, and a threshold circuit or the like is adapted to shut off and reverse the motor when the power generated reaches a predetermined level.