Abstract: The present disclosure provides a thermal-stress-pore pressure coupled electromagnetic loading triaxial Hopkinson bar system and test method, the system mainly consists of an electromagnetic pulse generation system, a servo-controlled axial pressure loading system, a servo-controlled confining pressure loading system, a thermal control system, a pore pressure loading system, a bar system, and a data monitoring and acquisition system. Based on the conventional Hopkinson bar, the present disclosure creatively introduces a real-time loading and control system for confining pressure, thermal, and pore pressure, aiming to solve the technical problem that the existing test apparatus cannot be used to study dynamic response of deep rock mass under the coupling effect of thermal-stress-pore pressure and dynamic disturbance during dynamic impact loading.

Abstract: A device for forcibly inserting a surgical implant into a receiving bone (4), by impaction, comprising an impactor (10) which exerts an impact force on the implant and is associated with at least one sensor (12). The sensor (12) measures the deformation of the impactor (10), and provides a measurement signal representing the temporal variation of the deformation during an impact. The sensor (12) is connected to a processing unit (30) configured to calculate, on the basis of the temporal variation of the deformation of the impactor (10) during the impact, an indicator representative of the level of contact between the implant and the receiving bone (4).

Abstract: A material testing apparatus includes an actuator to apply a force to a load head according to electronic control signals. The load head supplies a load to a material specimen in a first dimension. A plurality of load line displacement (LLD) reference points extend radially outward from the load head; and a plurality of LLD measuring devices correspond to the plurality of LLD reference points. Each LLD measuring device is positioned to detect a position of a corresponding LLD reference point along the first dimension and is configured to transmit position signals to a controller programmed to perform a performance test on the material specimen using feedback control based on a combination of the position signals, including an average of the position signals.

Abstract: A system for detecting forces on and measuring deformation of an anthropomorphic test device (ATD) includes a plurality of body parts and at least one optical fiber supported by and in contact with at least one of the body parts. The body parts form the ATD and simulate at least a part of a human body and the articulation of the human body. The optical fiber extends between a first end and a second end and comprises a plurality of sensors disposed between the ends. An emitter is in communication with the optical fiber for emitting a light having a predetermined band of wavelengths through the optical fiber that is reflected by the sensors and an interrogator is in communication with the optical fiber for detecting the reflected light from the sensor such that changes to the reflected light indicate a strain on the at least one body part.

Abstract: An accelerated life testing (ALT) system for the pressurization of corrosive media, such as seawater, at high pressures and at elevated temperatures (up to about 70° C.) for extended periods of time. The interior of a pressure vessel is coated in an inert ceramic/epoxy coating that provides adequate corrosion protection from the corrosive media. A fabric reinforced nitrile diaphragm separates the corrosive media from hydraulic actuating media, such as oil. The hydraulic actuating media is pressurized, which deforms the diaphragm into the corrosive media, thereby increasing the pressure. The diaphragm and supplementary flouroelastomer seals isolate the corrosive media from pressure generating, monitoring, and safety equipment. The temperature of the entire vessel and contents is maintained by complete immersion in a heated, filtered water bath. The system is particularly useful for ALT experiments on components intended for sea floor and long term deep ocean environment operations at about 6000 psi (41.4 MPa).

Abstract: The present invention provides a gaming system for playing a boxing inspired game. The gaming device includes two vests that communicate with each other and keep score via wireless technology. The game is played by two players at a time with the general objective being for a player to hit their opponent's vest as many times as possible within the designated time period. The device allows players to engage in three different modes. Score tracking is announced by audio and does not require any additional devices for viewing the score.

Abstract: Whether an internal defect is present in an inspection target is readily judged. Provided is an inspection method for an inspection target that is a layered structure including an FRP material and/or a structure made of resin, the method including the steps of: tapping, with a tapping tool, an inspection target area on a surface of the inspection target; detecting, by an accelerometer mounted to the tapping tool, an acceleration signal corresponding to acceleration of the tapping tool due to reaction force against the tapping; recording waveform data about the detected acceleration signal; creating a contour map corresponding to the inspection target area, based on the recorded waveform data; displaying the contour map on a display unit; and judging whether an internal defect is present in the inspection target, based on the contour map displayed on the display unit.

Abstract: Systems and methods may display an indication of an impact force from a driving device. A method may include displaying the indication of the impact force with a light. The light may be located on the driving device, a component attached to the driving device, a user interface, or the like. Different colors may be used to indicate different impact forces. For example, a first light color may correspond to an impact force below a first threshold, a second light color may correspond to an impact force above a second threshold, and a third light color may correspond to an impact force between the thresholds. The impact force may be detected using a sensor, which may output a voltage to cause the illumination.

Abstract: Embodiments provide systems, apparatuses, and method for determining the Modulus of Elasticity (MOE) of a wood workpiece based on the travel time and/or velocity of an impact-induced acoustic stress wave. A housing may be configured to reduce extraneous acoustic waves and/or contaminants near an acoustic transducer to thereby reduce errors in the detection/identification of the acoustic stress wave. A computer system may be programmed to determine the MOE of the workpiece based on the travel time and/or velocity of multiple acoustic stress waves induced by corresponding impacts at respective locations along the end of the workpiece as the workpiece travels in a first direction. Corresponding methods and an induction system for rapidly and repeatedly striking the end of the workpiece are also described herein.

Abstract: An inspection apparatus comprises a chassis position/attitude estimator to estimate position/attitude information of a moving body and generate a chassis position/attitude estimation signal, a hammering tester hammer part error signal generator to generate a hammering tester hammer part error signal, a hammering tester hammer part position/attitude signal generator to generate a hammering tester hammer part position/attitude signal, a first sensor data frequency characteristic interpolator to generate a first sensor data frequency characteristic interpolation signal from the received chassis position/attitude estimation signal, a second sensor data frequency characteristic interpolator to generate a second sensor data frequency characteristic interpolation signal from the received hammering tester hammer part error signal and the received hammering tester hammer part position/attitude signal, and a hammering tester hammer part position/attitude estimator to generate a hammering tester hammer part position/att

Abstract: An apparatus for monitoring the movement of a foundation may include an elevation sensor to detect changes in elevation of the foundation and positioned on the foundation to broadcast a signal responsive to the movement of the foundation; and a receiver to receive the signal responsive to the movement of the foundation and positioned off the foundation to provide a absolute measurement of the movement of the foundation.

Abstract: The present invention relates to a boxing fitness device and a detection method thereof, the boxing fitness device of the present invention includes a frame, punching zones, prompting devices, sensing devices, a first wearable device, a second wearable device and a computation unit. The punching zones are disposed in the frame and the prompting devices are disposed on the punching zones, respectively. When a left hand or a right hand of a user touches one of the punching zones, the sensing devices can sense a first to-be-sensed part of a first wearable device or a second to-be-sensed part of a second wearable device worn on the hands of the user. As a result, the boxing fitness device and the detection method thereof of the present invention can sense the first to-be-sensed part and the second to-be-sensed part to detect the user's correct punching action.

Abstract: A material testing apparatus includes an actuator to apply a force to a load head according to electronic control signals. The load head supplies a load to a material specimen in a first dimension. A plurality of load line displacement (LLD) reference points extend radially outward from the load head; and a plurality of LLD measuring devices correspond to the plurality of LLD reference points. Each LLD measuring device is positioned to detect a position of a corresponding LLD reference point along the first dimension and is configured to transmit position signals to a controller programmed to perform a performance test on the material specimen using feedback control based on a combination of the position signals, including an average of the position signals.

Abstract: An inspection operator can perform a hammering inspection without operation to move an inspection device to a location to be inspected, and the hammering inspection can also be performed to the location to be inspected where a vehicle has difficulty in entering. An inspection system includes a flying device including a hammering inspection unit that performs an inspection and a flying unit that flies with the hammering inspection unit, a ground-side device that is fixedly installed at a position relative to a location to be inspected and detects a position of the flying device, and a flight instruction unit that controls the flying device in such a way that a forwarding direction of the flying device is a direction from the ground-side device to the location to be inspected based on the position of the flying device.

Abstract: A measuring device and method for horizontal dynamic impedance of specified foundation depth based on differential response analysis of pulse excitation. The measuring method is realized based on the measuring device. Two rigid piles with different lengths are embedded into different foundation depths. Motion characteristics of the two rigid piles in the process of collision impact with the outside are different under the same pulse excitation. Dynamic impedance of specified foundation depth is deduced from the formula according to the differential response. Single-degree-of-freedom oscillators are arranged on the pile heads of the two piles, and strain gauges are arranged on the bottoms of the single-degree-of-freedom oscillators to obtain stress states of the single-degree-of-freedom oscillators, thereby calculating the relative displacements of the single-degree-of-freedom oscillators. This is simple in structure, reliable in measurement and convenient in data collection and processing.

Abstract: A shock testing machine including: a test platform for holding one or more objects to be shock tested, the test platform having an impact surface; a fixed member having a surface disposed a predetermined distance from a corresponding surface of the test platform, the test platform being movable such that the surface of the test platform can contact the corresponding surface of the fixed member upon an impact to the impact surface; and a flywheel having one or more cams for contacting the impact surface upon rotation of the flywheel such that the impact of each of the one or more cams on the impact surface causes the surface of the test platform to impact the corresponding surface of the fixed member to produce a shock in the one or more objects to be tested.

Abstract: Methods and systems are provided for determining cement quality in an outer annulus of a multi-string cased wellbore having an inner annulus of mud. Data from a sonic logging tool is processed to obtain a slowness dispersion. The slowness dispersion is compared to a plurality of model slowness dispersions generated for a plurality of different values for cement quality in the outer annulus. The cement quality in the outer annulus is determined based on the comparison.

Abstract: A martial arts target handle comprising; (a) an accelerometer providing a first data output signal; (b) an altimeter providing a second data output signal; (c) a CPU receiving and storing said first and second data output signals; and (d) a power source providing power said accelerometer, altimeter and CPU.

Abstract: A material testing apparatus includes an actuator to apply a force to a load head according to electronic control signals. The load head supplies a load to a material specimen in a first dimension. A plurality of load line displacement (LLD) reference points extend radially outward from the load head; and a plurality of LLD measuring devices correspond to the plurality of LLD reference points. Each LLD measuring device is positioned to detect a position of a corresponding LLD reference point along the first dimension and is configured to transmit position signals to a controller programmed to perform a performance test on the material specimen using feedback control based on a combination of the position signals, including an average of the position signals.

Abstract: An example vehicle for monitoring windshield vibrations for vehicle collision detection includes a windshield, a vibration sensor coupled to the windshield to detect window vibrations of the windshield, a first accelerometer to detect vehicle body vibrations of a vehicle body, and a restraint control module. The restraint control module is to detect an event based upon the window vibrations and determine whether the event is a collision event or a non-collision event responsive to comparing the window vibrations and the vehicle body vibrations.

Abstract: The athletic touch-sensing equipment: 1) senses when contact is made between the first competitor and a second competitor; and, 2) detects when a threshold of contact is exceeded and generates an audio alarm and a visual alarm to indicate that contact is detected. The athletic touch-sensing equipment comprises a uniform, a plurality of gloves, a plurality of sensors, and an alarm circuit. The plurality of sensors and the alarm circuit are installed in the uniform. Each individual sensor selected from the plurality of sensors is activated when a glove selected from the plurality of gloves touches the individual sensor. The alarm circuit monitors the plurality of sensors and initiates the audio alarm and the visual alarm when two or more individual sensors have been contacted by one or more gloves selected from the plurality of gloves.

Abstract: A retightenable wedge system for tightening a coil in a slot of a generator stator bar is presented. The retightenable wedge system includes a first filler layer, a spring member, a second filler layer and a retightenable wedge assembly. The retightenable wedge assembly includes a slot wedge having an aperture, a tightening member having form fit feature and a locking member having mating form fit feature. The tightening member is tightenable in the aperture such that a radial load is applied on the second filler layer for tightening the coil in the slot. The tightening member is locked in place in the aperture by an engagement between the form fit feature of the tightening member and the mating form fit feature of the locking member such that the tightening member is restrained from backing out of the slot wedge.

Abstract: A test system includes a measuring apparatus for measuring a property of a device under test and a test hammer for carrying out a strike on a section of the device. The test hammer includes a motion sensor and a transmission module for transmitting a signal if the motion sensor detects the start of the strike, and/or for transmitting a signal if an impact is detected. Further, a test signal generating unit generates a test signal, a test signal output unit outputs the test signal to the device under test, a measuring signal receiving unit receives a measuring signal produced in response to the output of the test signal, an analyzing unit determines a quantity of a component of the measuring signal, a transmission module receives a control signal from an external source, and a real-time controller switches from the energy-saving mode.

Abstract: A true stress testing system broadly comprising a force input machine, an imaging system, and a computer. The imaging system includes a light source for projecting a light beam at the specimen in a first direction and a camera positioned on an opposite side of the specimen for receiving portions of the light beam not blocked by the specimen such that a shadow image of the specimen is created via the camera. The computer may determine a minimum dimension of the specimen perpendicular to the first direction at a point in time over a plurality of points along the force axis via the shadow image of the specimen such that the processor accounts for changes in position of the minimum dimension along the specimen. A true stress of the specimen may then be determined according to the minimum dimension of the specimen perpendicular to the first direction at the point in time.

Abstract: A 2-stage force measuring system particularly useful for a high capacity press. A first stage load cell provides a high force range for measurements over 1,000 lbs. A second stage load cell is for measurements below 1,000 lbs. The assembly improves sensitivity and reduces noise by a factor of 16 (16,000 pounds/1,000 pounds) when pressing less than 1,000 pounds. If a press cycle exceeds 1,000 pounds, the force monitor will automatically and seamlessly transition from the low range load cell to the high range load cell. If the force required is less than 1,000 pounds, only the low range load cell will detect the load, providing a dramatic improvement in force resolution and accuracy.

Abstract: The invention relates to a method for at least qualitatively determining at least one physical and/or chemical characteristic of a laminate panel (2) by means of a mobile radio device (14), wherein the method comprises the following steps: (a) arranging the mobile radio device (14) on a surface (10) of the laminate panel (2); (b) measuring at least one physical and/or chemical measurement variable by means of a measurement instrument (28) integrated into the mobile radio device (14); and (c) at least qualitatively determining the at least one physical and/or chemical characteristic from the at least one measured physical and/or chemical measurement variable.

Abstract: Drop-weight tower (110) for reproducibly initiating a crack in a material sample for fracture mechanics testing comprising a base (120) with a top surface upon which a sample holder (124) is mounted to grip a material sample, an attachment column (140) having a linear rail (142), a carriage (162) attached to the linear rail (142) and a stage (164) is attached to the carriage. The stage (164) includes a vertical rod (184) and a razor-blade holder (178). A weight is slidably mounted to the vertical rod (184). The carriage is used to adjust the height of the stage (164) relative to the material sample. A hammer (180) slides up and down the vertical rod (184) to apply consistent and reproducible force on the razor (178) that then initiates the crack in the material sample.

Abstract: The present disclosure relates to a device for detecting a liquid crystal module and a method for detecting the quantity of liquid crystal. The method includes a cover for fixedly accommodating the liquid crystal module. An accommodation space for accommodating collision units is formed between the liquid crystal module and the cover, the collision units being connected to the top wall of the cover through elastic members. The collision units are spaced from the liquid crystal module in a certain distance in a static status, and collide with a panel of the liquid crystal module through vibration of the cover in the vertical direction during detection. The device for detecting a liquid crystal module improves the detection efficiency.

Abstract: Methods to classify a proppant with respect to functional performance is described and includes measuring a coefficient of restitution for the proppant. Methods to select a proppant, methods to design a proppant, methods to predict proppant performance in a subterranean formation, and methods for providing product specifications for proppants are also described as well as other uses.

Abstract: This invention relates to a method and an apparatus for characterizing eggshells of eggs, the eggs being supported, comprising: —deforming the eggshell, —scanning the eggshell with a laser beam of a Self Mixing Laser Vibrometer (SMLV) with scanning signals, whereby a reflection light signal of reflection light is obtained, —processing scanning signal and the reflection signal with the SMLV, whereby a mixed signal with crack information is obtained, —during scanning moving the eggs relative to the SMLV, —comparing the signals with preset criteria and characteristics of such eggs, whereby comparative data are obtained, and —characterizing the eggshells on the basis of the comparative data.

Abstract: A device for determining a bearing preload of a rolling-element bearing includes an exciter configured to be attachable to a component of the rolling-element bearing and to excite the component of the rolling-element bearing and cause it to vibrate when the rolling-element bearing is not rotating, at least one vibration sensor configured to be attachable to the component or to a further component of the rolling-element bearing and to record (capture) a mechanical reaction, in response to the excitation, of the component or the further component of the rolling-element bearing, and an evaluating circuit configured to receive the sensor signal and provide an evaluation signal based on the sensor signal, the evaluation signal including information about the bearing preload. An associated method and computer program are also disclosed.

Abstract: This fastener driving device is equipped with an impact force applying device that repeatedly applies impact forces to a fastener; and a load cell that detects a reaction force acting on the impact force applying device. The impact force applying device stops the applying of the impact force to the fastener on the basis of a detection result of the reactive force.

Abstract: A system and method are provided for translating gross human movement into electronic signals and therapeutic, training, or educational uses for the system. An exercising or video gaming system, comprising: a floor pad controller, and a striking controller. The floor pad controller having force sensor(s) and/or placement sensor(s) arranged in a pattern in the plane of a ground or floor. The striking controller having force sensor(s) and contact sensor(s) arranged in an curved grid between the outer layer of the striking controller and an inner core. Applying force to any sensor(s) in the floor pad controller or striking controller executes an action in response to an instruction from the exercising or video gaming system; and an inner core returnably coupled to a ground or floor of a room, so that the striking controller returns to an upright position after being struck by the user.

Abstract: Provided is a sound source control information generating apparatus, adapted for performing slapping techniques. According to the present invention, information based on an output value of a first sensor that detects striking on the housing is stored in a memory means. If striking on the struck head of a percussion instrument is detected based on an output value of a second sensor that detects striking on the struck head, whether an output value equal to or greater than a predetermined value is obtained from the first sensor in a predetermined time interval before a timing of detecting the striking on the struck head is determined based on the information stored in the memory means.

Abstract: A device and a method provide for the non-destructive simulation or reproduction of driving situations involving collisions and/or near-collisions between a test vehicle and a target object, while testing driver assistance systems or anticipatory vehicle sensor systems of the test vehicle. The target object is moved along a guide rope, for example by a drive rope. If a load exceeds a threshold value during a collision of the test vehicle with the target object, then the target object decouples from the guide rope.

Abstract: The present invention provides a tapping hammer for tapping test, which can help a user to accurately control the tapping force during a tapping test. The tapping hammer comprises a hammerhead and a handle supporting the hammerhead, and further comprises an alarm, a power source and a conductor, a hollowed-out region is provided in the interior of the hammerhead, the hammerhead is elastically deformable and electrically connected to a first electrode of the power source; the conductor is fixed in the interior hollowed-out region, not electrically connected to the hammerhead while no tapping force is exerted on the hammerhead and electrically connected to the hammerhead while a tapping force larger than a certain amount is exerted on the hammerhead; a first electrode of the alarm is connected to the conductor, a second electrode of the alarm is connected to a second electrode of the power source.

Abstract: Systems and methods are described for concurrently applying loads to multiple test specimens. The systems and methods are useful for cyclical tensile loading of specimens such as in fatigue strength evaluations. The systems and methods are also useful for low frequency cyclical loading evaluations.

Abstract: A tire pressure measuring device is disclosed. The device includes a data generating impact module for striking a pneumatic tire, generating data correlative to the force imparted to the tire as a function of time and transmitting the data to a data gathering module. A data gathering module receives the data from the data generating impact module and communicates the data to a data processing module. A data processing module receives the data from the data gathering module, processes the data to determine the pressure of the pneumatic tire and communicates the determined pressure of the pneumatic tire to a tire pressure display. A tire pressure output display receives the determined pressure of the pneumatic tire and displays the calculated pneumatic tire pressure.

Abstract: There is provided an electrodynamic modal test impactor system and method. The system has a controller device and an impactor assembly coupled to the controller device. The impactor assembly has a housing and a permanent magnet positioned within the housing. The impactor assembly further has a voice coil positioned within the housing in a magnetic gap of a magnetic yoke housing. The voice coil is driven by the controller device. The impactor assembly further has a drive shaft supported by two or more support elements. The drive shaft is attached to the voice coil and is driven by the voice coil. The impactor assembly further has a load cell attached to a free end of the drive shaft and a biasing device positioned within the magnetic yoke housing.

Abstract: Stated is an impact test device for simulating an impact of a body on a vehicle, which impact test device comprises a movable carriage and an actuator that is attached to the movable carriage. With the movable carriage at a standstill the actuator can move in a linear manner an impact body against the vehicle in order to deform the vehicle and to accelerate the movable carriage away from the vehicle. Since the mass of the actuator is significantly lighter than that of the movable carriage, termination of the impact test may take place very quickly.

Abstract: A helmet blastometer for characterizing the direction, speed, magnitude, and duration of a blast event to determine the likelihood of blast-induced traumatic brain injury (biTBI). Time of arrival (TOA) gage sensors are mounted on a rigid outer shell of the helmet each producing a TOA signal in response to a fast rising blast induced positive pressure change above a predetermined threshold. A receiver analyzes the positive pressure changes from the gages to determine direction, speed, and magnitude of a blast. Other TOA gauge sensors can be used to produce a TOA signal in response to a negative pressure change below a predetermined threshold. The positive and negative pressure change TOA signals are used to determine blast duration. A second set of internal contact pressure sensors is connected to an inner liner of the helmet to detect contact pressure on a user's head to determine if biTBI has been sustained.

Abstract: An impacting testing device is provided. The impacting testing device comprises a first platform, a second platform, a plurality of first suspension devices, at least one impact assembly and a plurality of second suspension devices. The at least one impact assembly is disposed on the second platform and faces the first platform for providing at least one impact force to the first platform, and thus, the impact testing is executed on an object disposed on the first platform.

Abstract: There is disclosed an assembly, a system and a method for modal impart testing. The assembly has a first set of components. The first set of components include an impact assembly, a cycle control element coupled to the impact assembly, and a signal response measuring device positioned opposite the impact assembly. The assembly further has a second set of components separate from the first set of components. The second set of components include a first controller coupled to the cycle control element and a second controller coupled to the signal response measuring device. The first set of components and the second set of components form a modal impact testing assembly for modal impact testing. The impact assembly of the modal impact testing assembly is configured to impact a test element rotating at operational speeds.

Abstract: A tool for inspecting timber of a structure for the presence of damage to exposed timber caused by a pest. The tool includes a head having a substantially flat rear portion, and a generally concave front portion that forms an edge configured to permit the head to penetrate into a surface deviation in the timber, or into a boundary between the timber and a floor covering over a substantial portion of the height of the floor covering.

Abstract: A master verification assembly includes a plurality of plunger devices. Each of the plunger devices includes a piston that is axially moveable between a raised position and a depressed position. When placed in a washing assembly, each of the plunger devices is aligned with a nozzle. The nozzles dispense a cleaning fluid under pressure. An axial force applied by the dispensed cleaning fluid depresses the pistons into the depressed position, whereupon the pistons disposed in the depressed position are axially secured in an indicator position. Upon removal of the master verification assembly from the washing assembly, depressed pistons in the indicator position indicate proper function of the nozzles, whereas pistons disposed in the raised position indicate improperly functioning nozzles.

Abstract: An explosive device test fixture which includes a horizontal accelerator having a track, a main sled, and a mini-sled. The main sled is able to be travel on the track, and has main sled rails. The mini-sled is smaller than the main sled such that the mini-sled can travel along the main sled rails. When the horizontal accelerator is actuated it fires a pulse. The pulse causes the main sled to travel along the track, while the mini-sled remains stationary causing the main sled to hit the mini-sled and simulate acceleration forces on the mini-sled similar to acceleration forces in an actual explosion.

Abstract: The present invention provides a tapping hammer for tapping test, which can help a user to accurately control the tapping force during a tapping test. The tapping hammer comprises a hammerhead and a handle supporting the hammerhead, and further comprises an alarm, a power source and a conductor, a hollowed-out region is provided in the interior of the hammerhead, the hammerhead is elastically deformable and electrically connected to a first electrode of the power source; the conductor is fixed in the interior hollowed-out region, not electrically connected to the hammerhead while no tapping force is exerted on the hammerhead and electrically connected to the hammerhead while a tapping force larger than a certain amount is exerted on the hammerhead; a first electrode of the alarm is connected to the conductor, a second electrode of the alarm is connected to a second electrode of the power source.

Abstract: Devices and methods are provided for testing weld strengths of a test coupon joint. A test coupon is positionally fixed to a base of the testing device. A punch assembly having a head portion is provided so as to exert an axial force against an upright part of the test coupon to thereby determine weld strength between the planar and upright parts of the test coupon (e.g., a maximum force at which weld failure occurs).

Abstract: There is provided an electrodynamic modal test impactor system and method. The system has a controller device and an impactor assembly coupled to the controller device. The impactor assembly has a housing and a permanent magnet positioned within the housing. The impactor assembly further has a voice coil positioned within the housing in a magnetic gap of a magnetic yoke housing. The voice coil is driven by the controller device. The impactor assembly further has a drive shaft supported by two or more support elements. The drive shaft is attached to the voice coil and is driven by the voice coil. The impactor assembly further has a load cell attached to a free end of the drive shaft and a biasing device positioned within the magnetic yoke housing.

Abstract: A mouth guard comprises a base member configured to fit inside the mouth of a user, and at least one shock-sensing and indicating device coupled to the base member. In one exemplary embodiment, the shock-sensing and indicating device is a passive shock-sensing and indicating device that detects a shock substantially along a selected axis with respect to the base member. In another exemplary embodiment, the at least one shock-sensing and indicating device detects a shock substantially along a plurality of selected axes with respect to the base member, each selected axis being substantially orthogonal from another selected axis. The shock-sensing and indicating devices can be configured to detect different levels of shock. In one exemplary embodiment, the shock-sensing and indicating device comprises a multi-component chemical-reaction system, such as a chemi-luminescent reaction system.