Abstract: This patent describes devices and methods to evaluate and compare the effectiveness of protective equipment in providing protection to players of contact sports, and to determine if a given protective product (pad) is compliant with a specified performance standard. To simulate the impacts experienced by these players, a pad-protected specially modified and instrumented manikin is impacted with solid loads of various weights at various speeds. The impacts are designed to model the impact forces and impact times encountered in typical game collisions. For each impact, measurements are made of the force exerted onto the pad, and the parts of this force that are transmitted through the pad onto various locations on the manikin, as a function of time.

Abstract: A method and apparatus for improving the accuracy and precision of drop impact sensing data utilized for testing the impact-absorbing capacities of surfaces, especially playground surfaces used by children, for compliance with relevant standards. A head form missile is equipped with onboard sets of high-g and low-g accelerometers for timing a period of free-fall of the missile, as well as for measuring acceleration due to impact at the end of the fall. Optimized results are obtained in a preferred embodiment by exploiting at least four accelerometers. Three of the accelerometers are sized for “high-g” measurements in each axis (X-, Y-, and Z-axes). At least one “low-g” accelerometer for (measuring in the Z-axis), or three accelerometers sized for “low-g” measurements in all axis (X-, Y- and Z-axes) are employed. Accelerometer readings obtained during the “zero g” free-fall period is used to cancel bias drift on all accelerometers.

Abstract: A micro-impact testing apparatus for measuring the impact characteristics of a microelectronics specimen exposed to an impact thereon. The apparatus comprises of a specimen holder for receiving a specimen to be tested, and an impact device. The impact device comprises of an impact head, a support member, at least one connecting element and a first flexural spring. The support member is connected to the connecting element in that the first flexural spring is firmly attached with its one end to the support member and with its other end to the connecting element. A second flexural spring, being at least substantially identical to said first flexural spring, is firmly attached with its one end to the connecting element and with its other end to the impact head so that the ends of the first and second flexural springs define, in an unloaded state of the flexural springs, a rectangle.

Abstract: A system and method for non-destructively testing the strength of bonded joints, particularly a bonded joint between two composite components, is provided. The method generally includes activating a source of rapid surface pressure application against a bonded assembly containing the bonded joint to create a shock load. The resulting shock load first generates compression and then tension within the bonded joint, along with surface motions proximate the bonded assembly, and a surface motion detector measures the surface motions to determine the minimum strength of the bonded joint. Accordingly, the surface motions are correlated to the strength of the bonded joint. Further, the magnitude of the impact may be adjusted to vary the amount of tension within the bonded joint to correspond with various load conditions.

Abstract: A process and device for revealing impact(s) received by a substrate make use of a film capable of being deposited onto said substrate and consisting of a matrix in which are embedded microcapsules intended to be broken during the impact and thus to release product(s) which they enclose and which is (are) endowed with different photoluminenscence properties according to whether it is (they are) encapsulated or released into the matrix.

Abstract: A method of determining fracture mode transition behavior (FMTB) of solid materials by using stress field modified miniature specimens. The method is an improvement in the method of determining mechanical behavior information from specimens only so large as to have at least a volume or smallest dimension sufficient to satisfy continuum behavior in all directions. FMTB of the material is determined from the measurements taken during the loading of the specimen resulting in the formation of cracks and/or the further propagation of cracks in the miniature specimen and/or fracture. The specimens are provided with grooves that induce additinal stress field modifying stress components in the specimens during the test. These additional stress components result in a desired stress state in the specimen which could not be achieved otherwise. The methods are useful in determining FMTB for the material, when the specimen thickness is smaller than previously thought necessary for valid FMTB determinations.

Abstract: An impact testing apparatus and process are provided. The apparatus comprises a thickness verifier to measure the thickness of each specimen. The apparatus further comprises a notcher and a notch verifier which are operative to first cut notches in a test group of specimens and to subsequently verify the accuracy of the notches. The apparatus further comprises a robotic gripper to sequentially deliver specimens to a vise for impact testing. The impact tester of the apparatus is operative to automatically assess the impact on each specimen. Additionally, the impact tester comprises optical sensors to assess the type of break of each specimen subjected to the impact test. A control unit receives input data from the various components of the apparatus, analyzes the data and prepares test reports.

Abstract: An apparatus for testing the surface properties of a material is disclosed. The apparatus includes an indentor which is suspended above the surface of a sample and dropped onto the sample. Several testing methods are also disclosed. Surface toughness is measured by dropping the indentor from a variable height and inspecting the surface for failure. Thin film strength is tested by making several drops from various heights and inspecting the surface for flaking of the layer. In addition, damping capacity can be measured by comparing the kinetic energy of the resulting from the drop of the indentor to the strain energy measured by a probe on the opposing surface of the sample.

Abstract: An impact testing machine in which a striker held by a fixed mounting is struck by a striker carried by a pivoted arm. A motor, connected to the arm by a clutch, accelerates the arm at such a rate that the striker achieves useful speed within one revolution from stationary, and the clutch operates to disengage motor and arm just before the striker hits the specimen so that the momentum of strike is independent of the motor. Various constructions and arrangements of motor and arm are disclosed whereby the necessary high angular acceleration may be imparted to the arm, including a lost-motion connection using a reeled wire bearing upon a pulley.

Abstract: Aluminum alloy armor weld joints are ballistic shock tested by first sepaely determining the ballistic impact capability of the components to be joined by the weldment by firing a plate proofing projectile at 0.degree. obliquity at each of said components at different striking velocities. The welded joint designs and welding procedures are then tested by firing the same projectile at the same angle at each of the components of the weldment so that the projectile impacts each component in the vicinity of the weld at a velocity comparable to the critical velocity of the component being impacted.

Abstract: A device for determining the tightness of a wedge used to close the slot of a dynamoelectric machine and firmly restrain the conductors installed in the slot, is in the form of a tapping hammer or similar tapping tool. The heat of the hammer contains an accelerometer which outputs a pulse signal having a duration representing the time the head is in contact with the wedge. The pulse signal duration is also related to the tightness of the wedge. Associated electronic circuitry measures the time duration and displays the measured value on a digital display on the hammer unless this display is inhibited. The strength of each blow is assessed by an integrating circuit which gives an output related to the strength of the blow. If this output is not within predetermined upper and lower limits, defining a "window", the display of the measured time duration is inhibited and instead the display indicates that the blow was too hard or too weak.

Abstract: A method of determining the impact fracture toughness K.sub.id of construction materials, for example structural steels or plastic materials, without the need of performing a load measurement at the striking hammer is provided. The elastic response of the specimen to the impact process, i.e. the dynamic stress intensity factor versus time curve, K.sub.I.sup.dyn (t), is determined in pre-experiments. The shadow optical method of caustics in reflection with an appropriate high strength steel is utilized for establishing this impact response curve. The dynamic fracture toughness for a given constructional material is then determined by performing an impact experiment and measuring the time to fracture t.sub.f. K.sub.Id is obtained from the measured t.sub.f -value and the pre-established impact response curve which corresponds to the experimental test conditions. The presented measuring procedure is used for determining the dynamic fracture toughness of two different steels at different test temperatures.

Abstract: A cryogenic impact testing method of Charpy's and falling weight types which can test a test piece without substantially exposing the test piece with the atmospheric air under the same test piece cooling space, temperature controlling space and impact testing space, and a cryogenic impact testing machine of Charpy's and falling weight types which can execute suitably the above method. Thus, the stable temperature of the test piece can be obtained at the time of testing with highly reliable measured result.

Abstract: A novel loading probe for fiber-matrix testing machines is made of diamond and has a truncated cone end for push-in and push-out tests of fibers in a fiber-matrix composite. The diameter of the probe body or shaft is greater than the diameter of the fiber to be pushed and the flat surface where the cone is truncated is at least one-half the diameter of the fiber. The included angle of the truncated cone is in the range of 55.degree. to 90.degree.. A useful compromise included angle is 70.degree..