Abstract: An example material testing apparatus includes: guide means; sample holding means for holding a sample; force means for applying force to the sample; a crosshead arranged to support at least a portion of one or both of the sample holding means and the force means, wherein the crosshead is moveable about the guide means; automated clamping means configured to apply a releasable clamping force between the guide means and the crosshead to secure the crosshead at a location with respect to the guide means, and a controller configured to control the automated clamping means to apply the clamping force between the guide means and the crosshead.

Abstract: An example material testing apparatus includes: guide means; sample test means for holding a sample and applying a test force to the sample; a crosshead arranged to support at least a portion the sample test means, wherein the crosshead is moveable about the guide means; crosshead drive means for moving the crosshead generally vertically about the guide means, wherein the crosshead drive means is driven by an electric machine in a driving configuration; and a controller arranged to: configure the electric machine into the driving configuration; control the crosshead drive means to move the crosshead generally vertically about the guide means; and configure the electric machine into a braking configuration, wherein in the braking configuration a winding of the electric machine is connected together with a low resistance connection.

Abstract: Safety systems and material testing systems including safety systems are disclosed. An example material testing system includes: an actuator configured to control an operator-accessible component of the material testing system; an actuator disabling circuit configured to disable the actuator; and one or more processors configured to: control the 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.

Abstract: A vibration test apparatus for vibrating a payload. The vibration test apparatus includes an inductive position sensor assembly which has a first member attached to a displaceable armature and a second member attached to a shaker frame. The inductive position sensor assembly is configured to generate at least one control signal indicative of an axial position of the armature based on a displacement dependent electromagnetic coupling between the first member and the second member.

Abstract: Once a sensor amplifier side connector of a cable unit for interconnecting a detector and a sensor amplifier is connected to the sensor amplifier, a gain resistor on the cable unit side and an instrumentation amplifier of the sensor amplifier are interconnected and the gain of the instrumentation amplifier is determined. As a result, the gain of the instrumentation amplifier is determined such that the magnitude of a signal that the sensor amplifier receives from the detector becomes a magnitude optimal for an analog circuit in the sensor amplifier.

Abstract: A method of operating a material testing apparatus comprises conducting a test by applying a fluctuating load to a material specimen at a variable test frequency, measuring the temperature of the specimen during application of the load, and varying the test frequency on the basis of the measured temperature whereby to prevent the specimen from exceeding a predetermined maximum temperature during the test. A corresponding material testing apparatus is also provided.

Abstract: Provided is a material testing system that can prevent the influence of noise to obtain an adequate test result by reducing a variation in test force in a plastic region. The material testing system is provided with: a displacement meter 15 that measures a displacement in distance between gage marks on a test piece 10; measuring means adapted to measure a displacement in rotational angle of a servo motor 31 that moves a crosshead 13; a computing part 48 that successively computes a change ratio R that is a ratio between the displacement in distance and the displacement in rotational angle; and a feedback control part 49 that, on the basis of the change ration R, performs feedback control of the servo motor 31, wherein when the change ratio R exceeds a setting value, a value of a parameter K used for the feedback control is changed to a value that makes the influence of the feedback control small.

Abstract: A compression testing assembly for compression testing of a test material includes a testing stage with a first surface and a second surface. The test material is disposed between the first and second surfaces. The assembly also includes a thickness detector that automatically detects a thickness of the test material. Moreover, the assembly includes an actuator that moves at least one of the first and second surfaces toward the other of the first and second surfaces to compress the test material to a predetermined percentage of the detected thickness of the test material. Additionally, the assembly includes a load detector that detects a compression load of the test material and that detects a change in the compression load over time.

Abstract: An apparatus and method for predicting freeze-thaw durability of a cementitious composition specimen including cycling the specimen below and above the freezing point of water contained in the specimen and identifying the contraction and/or expansion of the specimen during the cycling.

Abstract: Provided is a material testing system that can prevent the influence of noise to obtain an adequate test result by reducing a variation in test force in a plastic region. The material testing system is provided with: a displacement meter 15 that measures a displacement in distance between gage marks on a test piece 10; measuring means adapted to measure a displacement in rotational angle of a servo motor 31 that moves a crosshead 13; a computing part 48 that successively computes a change ratio R that is a ratio between the displacement in distance and the displacement in rotational angle; and a feedback control part 49 that, on the basis of the change ration R, performs feedback control of the servo motor 31, wherein when the change ratio R exceeds a setting value, a value of a parameter K used for the feedback control is changed to a value that makes the influence of the feedback control small.

Abstract: A sensor module is provided having a compact housing containing a sensor. A low temperature co-fired ceramic substrate is located on the housing. The sensor and signal processing circuitry are located on the low temperature co-fired ceramic substrate. The sensor module further includes a metal shield substantially encapsulating the sensor.

Abstract: Apparatus is disclosed for testing the mechanical properties of a material. The apparatus comprises a sample container (10) adapted to be filled with a sample of the material, and a housing (20) within which the sample container (10) is, in use, fixedly mounted. The sample container (10) has a first, open face via which a compressive load can be applied to the sample and a second face (19) disposed orthogonally to the first, open face. At least a portion of the second face (19) is resiliently displaceable, outwardly of the sample container (10), in response to deformation of the sample brought about by application of the load.

Abstract: By measuring the pressure distribution between fabricating equipment and a product formed in that equipment, and optionally the sequence in which the pressure is applied, the quality of product formation may be optimized. In an illustrated embodiment, pressure sensors are placed between a turn-up bladder and a tire apex in tire building equipment, and the pressure applied by the equipment, and the sequence of pressure application are observed and are correlated with product quality.

Abstract: In bending type or shearing type dynamic viscoelasticity measurement, a static stress adjuster adjusts static stress to zero in order to effectively eliminate static stress caused by influences such as warp caused by thermal expansion of a specimen or residual stress, for instance. Further, a static distortion adjuster adjusts a varying speed of static distortion to zero in order to suppress an increase of the static distortion and prevent the specimen from being excessively distorted even when the specimen is soft and has little restoring force. A dynamic viscoelasticity measuring system includes the static distortion adjuster for adjusting the static distortion of the specimen and the static stress adjuster for adjusting the static stress of the specimen, and measures the viscoelasticity of the specimen by selective operation or cooperation of the static distortion adjuster and the static stress adjuster depending upon quality change of the specimen being measured.

Abstract: A Schottky-barrier sensor has a semiconductor substrate having a pair of metal contacts formed thereon. The contacts form a Schottky barrier at each interface between metal and substrate, and the substrate is mounted on a surface. Strain, temperature and other physical parameters which affect the Schottky-barrier potential can be measured by voltage or current measuring equipment conductively connected to the Schottky-barrier semiconductor device.

Abstract: A system and method are provided for adaptively controlling a muscle tissue specimen in order to emulate its in vivo environment. The system includes at least one stimulator for stimulating the muscle tissue specimen based on an initial control signal, wherein the stimulation preferably includes electrical and/or mechanical stimulation. A response signal is generated based on a response of the muscle tissue specimen to the step of stimulating. The response signal preferably represents force production of the tissue specimen. A controller is provided for modifying the initial control signal based on the response signal to obtain a final control signal, wherein the final control signal is used to elicit a desired response from the muscle tissue specimen. Advantageously, the system and method of the present invention can be used to adaptively control the stimulation of a muscle tissue specimen in a tissue culture environment.

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 system and method are provided for adaptively controlling a muscle tissue specimen in order to emulate its in vivo environment. The system includes at least one stimulator for stimulating the muscle tissue specimen based on an initial control signal, wherein the stimulation preferably includes electrical and/or mechanical stimulation. A response signal is generated based on a response of the muscle tissue specimen to the step of stimulating. The response signal preferably represents force production of the tissue specimen. A controller is provided for modifying the initial control signal based on the response signal to obtain a final control signal, wherein the final control signal is used to elicit a desired response from the muscle tissue specimen. Advantageously, the system and method of the present invention can be used to adaptively control the stimulation of a muscle tissue specimen in a tissue culture environment.

Abstract: A test apparatus is formed of an error area computing device, an upper limit value computing portion and a delay time computing portion. The error area computing device computes an error area corresponding to a difference between waves of a request signal and an output signal to thereby correct control constants for a PID controller based on the error area. The upper limit value computing portion prevents the control constants from being corrected at values higher than upper limit values, and the delay time computing portion computes a phase delay time between the request signal and the output signal. In case the request signal has a higher frequency, the error area is computed as a value from which an error area due to the phase delay time is deducted. Thus, in the test apparatus, the control constants of the PID controller can be optimized for every cycle of an input signal, i.e. the request signal, and in the process of optimizing of the control constants, a bad influence is not exerted to a specimen.

Abstract: A method and device for determining the green tack of rubber blends. To obtain reliable and reproducible measurement results it is proposed to use two specimens (40') of rubber blends, the green tack of which is to be determined. Each of the specimens (40') comprises a measurement surface area (42) having a convex curvature, with which the specimens (40') are placed one on the other. During a predetermined time the specimens (40') are compressed at a predetermined pressure and subsequently parted from each other at a constant rate to determine the maximum parting force. The curved measurement surface areas (42) are generated by a specimen (40) being placed on the specimen platform (34) of a specimen mount (26, 28). Subsequently an orifice disk (36) is placed on the specimen (40) and locked in place in the compressed condition, for instance, by being firmly bolted in place.

Abstract: Foundry sand testing apparatus, method and system are provided for testing foundry sand. A computer foundry sand testing system includes at least one sensor for sensing predetermined characteristics of the foundry sand and for generating a signal. A processor coupled to the sensor processes the generated signal. A display is operatively controlled by the processor for displaying predetermined test information responsive to the generated signal. Predefined displays for receiving user selections and for displaying of test information are automatically generated. The generated displays of test information include real-time stress-strain curves and multiple calculated values utilizing the stress-strain curves.

Abstract: Method of finding the distribution of stresses on and in an elastic body from data about the pattern of a temperature variation pattern on the surface of the elastic body caused by the thermoelastic effect and also from data obtained by numerical analysis of the stresses. First, stress variations are adiabatically given to the actual elastic body. The pattern of temperature variations on the surface of the object caused by the thermoelastic effect is detected. Then, the sums of principal stresses inside the surface of the object are found from the temperature variation pattern. A plurality of free nodal points are established at the boundary of a model of a structure having the same shape as the actual object. A unit external force is applied to certain one of the free nodes. The sums of the resulting stresses at the internal points are found by numerical analysis.

Abstract: An apparatus for monitoring the growth of surface cracks in materials includes a means for applying a load to a specimen to simulate actual use of the specimen, means for illuminating the specimen, means for capturing images of the specimen, and means for processing the images to monitor crack growth in the specimen. Optionally, the means for processing can be used to control the other means.

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: For tying a compressed bale tending to expand primarily along a major axis, a bale tie made preferably from steel wire or alternatively from steel strap is bent to form two marcelled portions, which are characterized by sinusoidal undulations, which are oriented so as to be generally parallel to the major axis, and along which the tie can straighten to absorb tensile forces. A joint is formed at the opposite ends of the tie. Where bent to form the marcelled portions, the tie has an ultimate strength less than the ultimate strength of an undeformed portion of the tie but more than the ultimate strength of the joint. An apparatus for forming a wire with a marcelled portion comprises upper rolls and lower rolls, which are rotatably mounted and respectively on an upper block and a lower block. The upper block is pivotally mounted upon to the lower block.

Abstract: Mechanical testing apparatus and methods are disclosed for providing closed-loop dynamic mechanical testing under small loads. The testing machine includes an electrically-driven actuator and light weight load transducer. The load transducer converts the applied load into a voltage feedback signal, which is then fed into a closed-loop control means for regulating the applied load in response, in part, to the voltage feedback signal. The testing machine is extremely sensitive and is capable of testing samples with an applied load force of less than about 20 grams.

Abstract: A tensile test controller has both load and stroke control circuits that are coupled together to permit tensile testing a specimen while controlling the load on the specimen, and when the specimen yields, for safely and smoothly switching to stroke control to complete the test and break the specimen. The controller has circuits which provide control over the velocity of the actuator as the specimen yields, and to prevent the specimen from being placed into compression, and also to sense the plastic specimen deformation a desired amount after it has yielded, but before the stroke control function is activated. Simplified supervisory gates are used to insure that the appropriate signal is controlling the test.

Abstract: A method and apparatus for precisely controlling plastic strain rate during plastic deformation testing of a solid material such as a metal or plastic are described in which the effects of elastic strain rates associated with the specimens and machines used for such testing are eliminated by applying corrections proportional to the load on the specimen. Thus strain rate sensitivity, unaffected by the machine or specimen modulus can be measured. Strain rate sensitivity can be used to measure the activation volume of the specimen which may be used for quality control of material processing and/or manufactured articles.

Abstract: To impart prevailing torque to a nut, it is squeezed between two jaws. The moment that the nut contacts both jaws is determined by monitoring the relative acceleration of the jaws. The displacement of the jaws at this time gives the dimension across the flats of the nut. From this is subtracted the desired degree of deformation giving a target displacement. When this has been reached and sensed, the jaws are stopped and then opened.

Abstract: The signal output of a pressure transducer, measuring the increasing tensile load above a minimum level on a test specimen, is differentiated to produce an analog slope signal compared with an adjusted sensitivity voltage to generate a reset signal when the elastic limit of the specimen is exceeded. Through digital gate logic enabled above a minimum tensile load, the reset signal terminates loading of the specimen to prevent destruction thereof.

Abstract: A specimen testing apparatus is disclosed, including a sensing device for engaging a specimen mounted on a support, an electrical measuring system associated with the sensing device for producing an electrical signal that is a function of a variation in a physical characteristic of the specimen as determined by the sensing device, and an electromagnetic compensation system for applying a compensating force to the sensing device. In one operating condition (as, for example, when the thermal expansion properties of the specimen are being tested), the compensation system is operable to apply to the sensing device a force compensating for the weight of the sensing device, thereby to cause the sensing device to rest upon the specimen in a weightless force-free manner. Alternately, the compensation system may be operable to apply to the sensing device a supplemental force in the compressive stressing condition, as might be desired when penetration tests are to be conducted on the specimen.

Abstract: An analog digital control device having both analog and digital memory with multiple, readily accessible, selectable access ports to allow the control device to be quickly programmed by unskilled personnel and thus render the device particularly useful for the laboratory environment. The device includes a multiplexer switch for receiving both digital and analog input and for generating an output to a comparator to run an external component. An accessing and switching circuit is repeatedly used to access each of the multiple channels of digital memory in sequence.

Abstract: A testing device for applying a force to a material test sample includes a test fixture for engaging the test sample and a solenoid, operatively coupled to the test fixture, for applying a predetermined force to the test sample in response to a solenoid control signal. A strain gauge is mounted on the test fixture and provides an electrical output indicative of the force applied to the test sample. A force setting circuit provides an electrical output indicative of the predetermined force which is to be applied to the test sample. A solenoid control circuit is responsive to the output from the strain gauge element and to the output of the force setting element and provides a control signal to the solenoid such that the predetermined force may be applied to the test sample. The force setting circuit provides an electrical output having an adjustable rate of increase and an adjustable maximum level. A sample circuit monitors the output of the strain gauge to store the peak force applied to the test sample.

Abstract: A method of detecting very small structural flaws at loads below those which cause the flaws to propagate is disclosed. Certain phenomena and relationships of fracture mechanics are utilized in conjunction with the generation, detection and interpretation of thermal emission signals indicative of plastic deformation of the tested material.

Abstract: The apparatus of the invention measures and evaluates deformation characteristics of mechanically deformed test pieces, which characteristics depend upon the structural and mechanical properties of the test piece. The apparatus includes a loading device for supporting and placing a mechanical load on the test piece and a TV camera mounted for visually scanning the test piece as it is being deformed. The TV camera has an output for producing signals representative of the scanned picture. A control unit is connected to the output of the TV camera and produces control pulses responsive to the output of the TV camera and to a feedback signal from an evaluating unit. A first output of the control unit is connected to the loading device for controlling a program of mechanical load applied to the test piece. The evaluating unit has a first input connected to the output of the TV camera and second input which is connected to a second output of the control unit.