Abstract: A system for ultra-high temperature in-situ fretting fatigue experiment, includes a heat preservation cover defining a, a heating device arranged in the mounting space, a first test sample, a second test sample, and a clamping device arranged in the mounting space. The first test sample and the second test sample are arranged at an upper end of the heating device along a horizontal direction. A mortise is formed at an end of the first test sample facing towards the second test sample. A tenon mating with the mortise is formed at an end of the second test sample facing towards the first test sample. The clamping device is configured to be clamped at two ends of the mated first test sample and second test sample and to apply a periodically reciprocating loading along a length direction of the first test sample and the second test sample.

Abstract: A non-destructive testing apparatus generates an electric current in a test coupon that is adjacent to the metallic structure. The non-destructive testing apparatus measures the electric current to produce at least one electric current measurement. The non-destructive testing apparatus correlates the at least one electric current measurement with the quantity of a predetermined iron oxide in the test coupon to determine a proxy for the degree of alternating current interference corrosion in the metallic structure.

Abstract: The multiple rig stress corrosion cracking testing device is a stress corrosion cracking and sulfide stress cracking testing device for engineering material specimens. The device includes a pressure and temperature autoclave chamber and also includes four testing rigs for simultaneous stress corrosion cracking testing of a circumferential notched tensile specimen, a compact tension or a double cantilever beam specimen, a cantilever bend specimen, and a center cracked plate specimen under varying experimental conditions. The specimens may be of similar or different materials.

Abstract: A screw device is provided which can detect damage to a groove of a screw shaft, the damage being hidden by a nut, with a high probability. At least two circulation components are mounted on a nut in such a manner as to form at least two circulation circuits that circulate rolling elements. The nut is provided with a sensor that detects a displacement of a groove of a screw shaft between the adjacent circulation circuits.

Abstract: A 3D printed fiber reinforced polymer composite having a nonlinear stress-strain profile created by a central layer and a plurality of recruited successive layers.

Abstract: A transmission mechanism with monitoring function includes a shaft, a moving part, a circulating device, a plurality of rollers and a monitoring module. The shaft has a roller groove. The moving part is movably disposed on the shaft. The moving part has a roller slot corresponding to the roller groove. The roller slot has an effective thread section and an ineffective thread section. The effective thread section and the roller groove together form a load path. The circulating device is disposed on the moving part. The circulating device has a return channel communicated with the load path. The return channel and the load path together form a circulating path. The plurality of rollers are disposed in the circulating path. The monitoring module includes a gathering body and a sensor. The sensor is for detecting a metal content of the lubricant in the gathering channel.

Abstract: A method for detecting a deterioration state in an elevator suspension member including electrically conductive cords uses a multiplexing unit (MU) to apply first and second alternating voltages to proximal ends of first and second groups of the cords respectively and connect the proximal end of a third group of the cords to a voltage measurement arrangement connected to a reference potential. Distal ends of the groups are connected together. A first neutral point voltage between the third proximal end and the reference potential is determined. The MU is switched to apply the first alternating voltage to the second proximal end, apply the second alternating voltage to the third proximal end and determine a second neutral point voltage between the first proximal end and the reference potential. The deterioration state of the suspension member arrangement is determined based on the first and second neutral point voltages.

Abstract: A method and a correspondingly configured device detect damage or defects in a support, including at least one tension member, for an elevator system. A pulse generator generates at least one electrical digital input signal that represents at least one first binary number and is fed to the tension member. After the digital input signal has passed through the tension member, it is detected as a digital output signal that likewise represents at least one second binary number. The second binary number is then compared, in particular compared digit by digit or bit by bit, with a setpoint binary number and/or directly with the first binary number. Damage in the tension member is determined on the basis of an issued comparison result. If the second binary number deviates from the setpoint binary number and/or from the first binary number, a fault message is generated.

Abstract: A wire netting, in particular a safety net, includes a plurality of helices which are braided with one another and at least one of which is manufactured of at least one single wire, a wire bundle, a wire strand, a wire rope and/or another longitudinal element with at least one wire, in particular made of a high-tensile steel. The wire is bendable in a reverse bend test in opposite directions, by at least 90° respectively, about at least one bending cylinder having a diameter of maximally 2 d, at least M times without breaking, wherein M may be determined (by rounding down if applicable) to be C·R?0.5·d?0.5 and wherein a diameter d of the wire is given in mm, R is a tensile strength of the wire in N mm?2 and C is a factor of at least 400 N0.5 mm0.5.

Abstract: A wire netting, in particular a safety net, has a plurality of helices which are braided with one another and at least one of which is manufactured of at least one single wire, a wire bundle, a wire strand, a wire rope and/or another longitudinal element with at least one wire, made of a high-tensile steel, and which includes a plurality of legs, which has a plurality of bending regions respectively connecting two legs, and which has a transverse extension along a frontal direction, perpendicularly to a main extension plane of the helix, wherein, in a press test between parallel plates, including a pressing by moving the plates along a press path in parallel to the frontal direction, a test piece of the helix, taken from the helix and including at least five legs and at least four bending regions, shows a spring characteristic curve which has in a press path force diagram, starting from a start of the press path, a first partial characteristic curve extending at least approximately linearly and having a first

Abstract: An elevator installation includes a car and at least one support device supporting the car. The support device has a plurality of electrically conductive tensile carriers that are arranged parallel to one another and which are substantially enclosed by a casing. The elevator installation further includes a monitoring device that connects the tensile carriers or groups of the tensile carriers in an alternating configuration as electrical resistances in a measuring bridge so that electrical resistances of different tensile carriers can be compared with one another by sensing a bridge voltage.

Abstract: A rig for testing an aerofoil component in four-point bending, which includes first and second fixtures movable relative to each other to apply a cyclically varying load to opposing aerofoil surfaces of the component. The first fixture has two first loading formations positioned to apply the load to one surface of the component, the formations being spaced apart in the spanwise direction of the component. The second fixture has two second loading formations positioned to apply the load to the other surface of the component, which are also spaced apart in the spanwise direction of the component and positioned relative to the first loading formations to apply the load in a four-point bending arrangement. The second fixture is continuously adjustable so that its loading formations move relative to each other in the direction of application of the load to balance the load between the formations during the cyclical load variation.

Abstract: A fatigue sensor for monitoring the health state of structural members is disclosed. The sensor has multiple parallel beams, each sensitive to different levels of fatigue, that are designed to fail prematurely but progressively as the sensor goes through the same fatigue cycles as the structural member it is attached to. Whenever fatigue levels on a particular beam of the sensor exceed the engineered number of fatigue cycles, that particular beam fails and sensor electronics can detect that failure and transmit this information wirelessly when interrogated by an external interrogator. Having multiple beams that fail after different numbers of fatigue cycles enables the health state of the structural member to be monitored, in that unlike normal fracture sensor that sense failure of the structural members after the actual fracture event, the present invention is capable of sensing imminent failure of the structural member before the actual failure occurs.

Abstract: One aspect of the inventive technology may be generally described as a method for determining test object deformation response that comprises the steps of moving a deformation force deliverer 1 to deliver deformation force 24 to a test object 3; adjusting a deformation force deliverer affecting input so as to meet at least one constraint while performing the step of moving the deformation force deliverer 1; deforming the test object 3 with the deformation force 24; and determining test object response to the deformation force. Corollary apparatus, in addition to other inventive apparatus and method aspects relating variously to test object deformation response determination are part of the inventive technology. Such aspects may relate to the use of a linear actuator 15 in a test object deformation and to identity of motion of a deformation force deliverer 3 and a force deliverer drive component 75, as herein described.

Abstract: A method of determining fatigue of a pressure-resistant component for high-pressure hydrogen made of a ferritic steel and provided in a high-pressure hydrogen gas environment is provided wherein when the material of the ferritic steel in the air has an ultimate tensile strength Su in the range of 958-1,144 MPa and the hydrogen gas environment has a pressure in a range to 45 MPa, then a fatigue strength in a gaseous hydrogen SH (MPa) for the pressure-resistant component provided in the high-pressure hydrogen gas environment is obtained by using equation (1): SH (MPa)=2,577?1.8925×Su (MPa). The influence of a high-pressure hydrogen gas environment on the pressure-resistant component for high-pressure hydrogen is determined based on the fatigue strength obtained by using the equation (1).

Abstract: A fatigue sensor for monitoring the health state of structural members is disclosed. The sensor has multiple parallel beams, each sensitive to different levels of fatigue, that are designed to fail prematurely but progressively as the sensor goes through the same fatigue cycles as the structural member it is attached to. Whenever fatigue levels on a particular beam of the sensor exceed the engineered number of fatigue cycles, that particular beam fails and sensor electronics can detect that failure and transmit this information wirelessly when interrogated by an external interrogator. Having multiple beams that fail after different numbers of fatigue cycles enables the health state of the structural member to be monitored, in that unlike normal fracture sensor that sense failure of the structural members after the actual fracture event, the present invention is capable of sensing imminent failure of the structural member before the actual failure occurs.

Abstract: A method is provided for determining the extent of cyclic stress fatigue suffered by a component comprising the steps of: (i) obtaining a gauge material which undergoes a continued progressive/cumulative and quantifiable change in at least one of its physical properties in response to repeated strain cycles applied to the gauge material, the quantifiable change being indicative of both degree of strain and number of cycles incurred during the repeated strain cycles; (ii) determining a correlation between an extent of the quantifiable change in the gauge material and an effect on said component of a corresponding number and degree of strain cycles; (iii) affixing the gauge material to said component to subject the gauge material to any strain encountered by an adjacent portion of the component; (iv) at least periodically determining the extent of said quantifiable change to the gauge material to determine the extent of cyclic stress fatigue undergone by the component.

Abstract: A testing system (100) is used to test a flip-type electronic device (80). The electronic device includes a cover (802) and a main body (801). A hinge (803) connects with the cover and the main body. The testing system includes a base (10), a plummer (20), a flipping device (30) and a control device (40). The plummer is fixed on the base for locking the electronic device. The flipping device is fixed on the base for opening and closing the cover of the electronic device. The control device includes an optical fiber sensor (42) for sensing the movement of the cover of the electronic device. The control device connects with the flipping device so as to control the flipping device.

Abstract: A method is provided for determining the extent of cyclic stress fatigue suffered by a component comprising the steps of: (i) obtaining a gauge material which undergoes a continued progressive/cumulative and quantifiable change in at least one of its physical properties in response to repeated strain cycles applied to the gauge material, the quantifiable change being indicative of both degree of strain and number of cycles incurred during the repeated strain cycles; (ii) determining a correlation between an extent of the quantifiable change in the gauge material and an effect on said component of a corresponding number and degree of strain cycles; (iii) affixing the gauge material to said component to subject the gauge material to any strain encountered by an adjacent portion of the component; (iv) at least periodically determining the extent of said quantifiable change to the gauge material to determine the extent of cyclic stress fatigue undergone by the component.

Abstract: A method for evaluating thermal fatigue resistance for a welding consumable alloy can include the following steps: placing a test specimen of a welding consumable alloy in a testing device such that a tensile load and a compressive load can be introduced to the test specimen; heating the test specimen to a first temperature; applying a compressive force to the test specimen while heating the test specimen; cooling the test specimen to a second temperature; and applying a tensile force to the test specimen while cooling the test specimen.

Abstract: An elevator load bearing member (22) monitoring device (20) has a controller (30) that applies a first signal (40) and a second signal (50) to at least one tension member (24) in the belt. The first signal (40) in one example has a plurality of (42) of a selected amplitude and duration. The second signal (50) includes a series of pulses (52) having a second, shorter duration and lower amplitude. The first signal is useful for providing information regarding a wear condition of the load bearing member. The controller utilizes a response to the second signal to determine a failure condition such as a broken load bearing member.

Abstract: Systems and methods for fatigue testing one or more stents based on measured electrical resistance levels of each stent. Pairs of lead lines from an ohmmeter are connected to a respective stent. The respective stent is mounted onto an expander having an interior tapered portion into which a correspondingly tapered expansion pin is received. Cyclic loading strains are applied to the respective stent as an expansion pin is inserted into a corresponding one of the expanders. Stent fracture or failure occurs when cyclic loading exceeds the stents architectural and material capacity. Such fracture fatigue or failure is identified by increased electrical resistance levels. Resistance may be continuously monitored to more readily identify the onset of fatigue or failure. The expansion pins extend from a movable plate, and the expanders comprise a part of corresponding stations that extend from a fixed plate.

Abstract: Systems and methods for fatigue testing one or more stents based on measured electrical resistance levels of each stent. Pairs of lead lines from an ohmmeter are connected to a respective stent. The respective stent is mounted onto an expander having an interior tapered portion into which a correspondingly tapered expansion pin is received. Cyclic loading strains are applied to the respective stent as an expansion pin is inserted into a corresponding one of the expanders. Stent fracture or failure occurs when cyclic loading exceeds the stents architectural and material capacity. Such fracture fatigue or failure is identified by increased electrical resistance levels. Resistance may be continuously monitored to more readily identify the onset of fatigue or failure. The expansion pins extend from a movable plate, and the expanders comprise a part of corresponding stations that extend from a fixed plate.

Abstract: An arrangement for detecting a load bearing failure includes a primary load-carrying system for bearing axially translatably a coaxial load, said primary load-carrying system having a rotor portion and an axially displaceable stator portion. A plurality of bearing balls is interposed between the rotor and axially displaceable stator portions. A detector, which may include any of a laser measuring, an ultrasonic measuring, or a linear variable transformer or electrical contact detects wear or actual or impending failure of the primary load-carrying system. A secondary load-carrying system may be provided for bearing the coaxial load upon the event of a failure of the primary load-carrying system. The primary load-carrying system is a recirculating ball screw arrangement wherein the plurality of bearing balls is disposed in part in respective helical grooves of the rotor and axially displaceable stator portions. Wear or escape of the bearing balls is detected.

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: An apparatus (10) for testing attachment features (26,28,30,32) of components (12,14) comprises a first member (16) having a first end (18), a second end (20), a first edge (22) and a second edge (24). The first edge (22) has a first firtree slot (26) to receive a first component (12) and the second edge (24) has a second firtree slot (28) to receive a second component (14). The first component (12) has a firtree attachment feature (30) to fit the first slot (26) and the second component (14) has a firtree attachment feature (32) to fit the second slot (28). The first end (18) of the first member (16) has flanges (34,36) extending laterally and the second end (20) of the first member (16) has flanges (38,40) extending laterally such that the first member (16) is substantially H-shaped in cross-section.

Abstract: A method and an apparatus for remotely and automatically monitoring for corrosion of a tank, pipe, or container with a gas or liquid environment using corrosion coupons that do not have to be removed from the environment for inspection and evaluation. The coupons are designed to fail when a specified level of corrosion occurs. A permanent magnet located on a coupon sensing system inside the corrosive environment is used to transmit the failure of the coupons outside the corrosion environment and across a wall or other boundary surface without requiring a power supply.

Abstract: A method of estimating the lifetime of a thermal barrier coating (14), which is applied to the surface of a member subjected to cyclical thermal loads, especially a vane and/or blade of a gas turbine, by means of a bond coat (12) lying in between the coating and the member, leads to more accurate results with simplified calculation by determining, in a first step, the amplitude of the normal stress (&Dgr;&sgr;n) perpendicular to the interface between the bond coat (12) and the thermal barrier coating (14) during cyclical loading, and calculating, in a second step, the number Ni of cycles to failure for every normal stress amplitude (&Dgr;&sgr;n) in accordance with the formula N i ⁢   = C ⁡ ( △σ n σ 0 ) m

Abstract: A bend-test device for wire harnesses capable of handling a plurality of samples at the same time. The bend-test device includes a fixed frame unit, a hinge unit with a fulcrum axis, and a mobile frame unit connected to the fixed frame unit via the hinge unit in a freely pivotable manner around the fulcrum axis. The fixed frame unit includes fixed-side panels respectively including holder holes, each of which holds a grommet carrying a wire harness. The fixed-side panels are arranged in a parallel relation to each other, and aligned perpendicular to the direction of the fulcrum axis, in a freely mountable and removable manner. Likewise, the mobile frame unit includes mobile-side panels respectively including holder holes, each of which holds another grommet carrying the wire harness. The mobile-side panels are arranged as mentioned above, so that each of the mobile-side panels can be opposed to a corresponding one among the fixed-side panels.

Abstract: The invention provides a method of simulating and estimating the minimum lifetime under repeated bending for a wire harness containing a plurality of electrical cables, by applying a compact and lightly equipped device. To this end, representative electrical cables, contained in the wire harness, are subjected to flexing and stretching until they fail under repeated bending, so that the number of bending cycles is obtained for each representative electrical cable. The minimum lifetime for the wire harness can then be estimated on the basis of the shortest cable lifetime that can be found among all the representative electrical cables tested.

Abstract: A cable assembly having a critical conductor and a sacrificial conductor and a critical conductor which has a fatigue life of a predetermined first length and the sacrificial conductor has a fatigue life of a predetermined second length shorter than the predetermined first length such that exposure of the cable assembly to repeated flexure or deteriorating substance causes the sacrificial conductor to fail before the critical conductor fails. Additionally, sacrificial conductors to be insulated with an insulation material less suited for the application so that the sacrificial conductors insulation will fail prior to the failure of the critical conductors. Positioning of sacrificial conductors around the circumference so failure from abrasion and chaffing will occur prior to critical conductors. A cable condition monitoring system for generating an alarm signal in response to the detection of a fault in the sacrificial conductors and a method for monitoring the condition of a cable assembly are also provided.

Abstract: A dovetail of a rotor blade is mounted in a complementary slot in a rotor disk. Life of the dovetail is simulated by providing a specimen dovetail mounted in a complementary slot in a fixture. Relative stiffness of the specimen dovetail and fixture are tailored to simulate the loading profile between the blade dovetail and rotor disk. Load is cycled between the specimen dovetail and fixture for determining life of the dovetail.

Abstract: A method, technique, and apparatus proof test an optical fiber interconnect by applying an ends off-set stress on the optical fiber until the optical fiber fails or breaks, either immediately (short-term strength), or as a result of the delayed-fracture/"static-fatigue" phenomenon for the given off-set, and, hence, for the given stress (long-term strength), imposed for the measured period of time. If, for instance, the short-term strength is addressed, the off-set is measured at the time of the failure, and the corresponding critical strain of the optical fiber is then predicted. In predicting the critical strain, the method and apparatus iteratively determine the total strain, including non-linear components thereof, for an optical fiber interconnect experiencing the measured ends off-set. The analytical model/method includes the steps of iteratively processing characteristic parameters associated with the optical fiber, and determining the non-linear strain associated with the optical fiber.

Abstract: A method of evaluating endurance of a vehicle wheel by computer simulation of a dynamic radial fatigue test. The modeling of the system is simplified by modeling the tire portion made of a nonlinear material by linear elements, and modeling each of the air pressure, the press-contact effect of the tire bead portion and the load applied through the contact between the tire and the drum is modeled as the direct load. With such a modeling, the stress applied to the vehicle wheel can be calculated by the linear analysis instead of the nonlinear analysis, and as a results thereof, the memory capacity and the calculation time are reduced.

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: Flux-focusing electromagnetic sensor using a ferromagnetic flux-focusing lens simplifies inspections and increases detectability of fatigue cracks and material loss in high conductivity material. A ferrous shield isolates a high-turn pick-up coil from an excitation coil. Use of the magnetic shield produces a null voltage output across the receiving coil in presence of an unflawed sample. Redistribution of the current flow in the sample caused by the presence of flaws, eliminates the shielding condition and a large output voltage is produced, yielding a clear unambiguous flaw signal.Maximum sensor output is obtained when positioned symmetrically above the crack. By obtaining position of maximum sensor output, it is possible to track the fault and locate the area surrounding its tip.

Abstract: A mechanical impact test is performed using an incremental mechanical loading apparatus having a loading head movable in a first direction and in a second direction opposite to the first direction, and a stationary cross piece. A starter specimen is mounted between the loading head and the stationary cross piece, such that the starter specimen extends in the first direction from the loading head and the movement of the loading head in the second direction applies a tensile load to the starter specimen. A test specimen is mounted to the loading head such that a mechanical reaction force generated by the breaking of the starter specimen is imparted from the starter specimen to the test specimen. To perform the test, the loading head of the incremental mechanical loading apparatus is moved in the second direction such that the starter specimen is loaded to failure, with the result that the failure of the starter specimen causes the application of an impact force to the test specimen.

Abstract: The integrity of structures may be determined by either one of two methods. In a first method, an impulse of energy is introduced into the structure, such as by striking the structure, and the induced vibration is measured and the modal damping factor is calculated, the modal damping factor being directly related to the integrity of the structure. In a second method, a continuous energy input is provided to the structure for inducing a continuous vibration in the structure. This continuous vibration is measured with a transducer and a modal damping factor is calculated with a computer. The computer uses an algorithm to estimate the modal damping factor of the structure by calculating a theoretical response of an idealized system from several assumed parameters and varying those parameters until the difference between the measured response of the structure and a theoretical response of the idealized system is within an acceptable margin of error.

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 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: There is provided an apparatus for predicting a tool life which reports a tool life ratio to an operator or a control device, when a remarkable change of work load values is detected. In a predicted life setting section 122, there is set a percentage of a quantity worked until the detection of the noticeable change of the work load values based on the workable quantity until the breakage of the tool which is regarded as 100%. A predicted residual work quantity calculating section 123 calculates a residual tool life value converted into a parameter at a point of time when an alarm is input from a work load monitoring section 121, on the basis of data of a work quantity accumulating section 120 and the predicted life setting section 122. A predicted residual work quantity outputting section 124 reports the residual tool life value to an operator or a control device.

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: To determine the optimum load a laminate member or element is capable of bearing, a three-dimensional progressive analysis is proposed in which the stress and strain states of each ply of the laminate are subjected to failure criteria. If there is failure, new ply stiffness parameters are calculated. Thereafter, the ply is tested with the new parameter until the optimal load is determined. If no failure is detected for a given stress and strain for the ply then the load may be incremented and again applied to the ply, for further testing. Alternatively, the same load may be applied to the ply for a further period of time, until the optimal load is determined and/or the analysis is deemed to be finished.

Abstract: An apparatus and method for inducing and measuring crack growth in a solid by using a double cantilever beam assembly which includes a fracture specimen with a notch that defines a pair of spaced outwardly extending beams terminating at an end where growth of a crack occurs, and a spring assembly for continuously urging the spaced beams apart with a substantially constant pressure that creates a spreading pressure at the end where crack growth occurs to stress the fracture specimen at the end. An electromagnet assembly is used to cyclically apply and remove the spreading pressure caused by the spring assembly.

Abstract: An apparatus and method for fatigue stress testing a vehicle wheel or the like includes a plate to which the wheel is mounted, and a clamping system for maintaining the wheel stationary. The clamping system fixes the vertical and lateral position of both the upper and lower lips of the wheel, to replicate operating conditions. A nonrotatable shaft is connected to the plate through a bushing. The shaft is connected at a point spaced from the plate to a rotating lateral loading assembly, which rotates relative to the shaft. The lateral loading assembly exerts a lateral force on the shaft simultaneous with rotation of the assembly, so as to cause wobbling of the shaft, which is transferred through the stress plate to the wheel.

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 and method for fatigue stress testing a vehicle wheel or the like includes a plate to which the wheel is mounted, and a clamping system for maintaining the wheel stationary. A nonrotatable shaft is connected to the plate through a bushing. The shaft is connected at a point spaced from the plate to a rotating lateral loading assembly, which rotates relative to the shaft. The lateral loading assembly exerts a lateral force on the shaft simultaneous with rotation of the assembly, so as to cause wobbling of the shaft, which is transferred through the stress plate to the wheel.

Abstract: A method and apparatus for determining crack growth in an elastomer. A horizontally elongate elastomeric test specimen is cyclically stretched crosswise by upper and lower rigid plates contiguously attached to the long edges on both sides. The lengthwise growth of a crack induced by a small cut at one vertical edge of the specimen is determined by measuring the stretching force at each end. The lower plate is reciprocated by a hydraulic actuator relative to the upper plate. Two load cells measure the forces at each end of the specimen. With the use of a computer program and the relative forces measured by the load cells, the crack growth can be calculated.

Abstract: A piezoelectric load cycle counter is provided for a multi-stationed strain-life tester. A plurality of test specimens are interposed between a fixed upper bracket and a lower reciprocating bracket and are cyclically flexed therebetween. Piezoelectric crystals maintained in association with the upper bracket with each of the test stations present an output signal on each flexure of the test specimen. These output signals enable a counter which counts the number of cycles of the lower bracket. When a specimen breaks, the output signal of the associated station terminates and the count for that station similarly terminates.

Abstract: A material specimen 12 containing a central hole is bolted (bolt 27) between two bearing guide plates 28 and 29. An applied load control 11 applies an applied load, either tension or compression, to one end of specimen 12 and a bypass load control 13 applies a bypass load to the other end of specimen 12. Both load controls have their control inputs supplied by a single input signal generator 24. The difference between the applied load and the bypass load is transmitted through bolt 27 and plates 28 and 29 to bearing load cells 30 and 31.