Abstract: An impact testing device is provided. The impact testing device comprises a plate and an impact generating module. The plate has a first surface for loading a test object. The impact generating module is fastened to the plate to apply an impact to the plate and actuate the plate along the first direction, the second direction and the third direction independently. Thereby, the impact testing device of this invention is adapted to apply the impact to the test object along any direction under control.

Abstract: An exemplary vibration testing device includes two mounting bases, a vibration generator located between the mounting bases, two pivot shafts, a supporting platform, two supporting elements and a control system. Each supporting element is telescopically extendable and retractable. The control system includes a lift control unit for controlling telescopic movement of the supporting elements, a first rotary control unit for controlling a rotationally movement of the vibration generator about the pivot shafts, and a second rotary control unit for controlling rotatable movement of the supporting elements about the pivot shafts. The control system is configured for controlling the vibration testing device to move between a first testing status in which vertical vibration forces are generated by the vibration generator and applied to the supporting platform and a second testing status in which horizontal vibration forces are generated by the vibration generator and applied to the supporting platform.

Abstract: A vibration characteristic measuring device is provided with a shaker, including a shaking section which reciprocates along an axis, and a mounting block fastened to a mounting surface of the shaking section. A disk drive suspension is mounted on the mounting block. The mounting block has a facing surface which faces the mounting surface of the shaking section. An adhesive member formed of a resin tape is disposed between the mounting surface and the facing surface of the mounting block. The adhesive member is deformable depending on a gap between the mounting surface and the facing surface. The adhesive member closely contacts both the mounting surface and the facing surface without a gap.

Abstract: A calibration device for calibrating a dynamic pressure sensor includes a power/control box and a portable calibration head disposed in electrical communication with the power/control box. The portable calibration head may include a calibration head housing having a housing opening and a speaker provided in the calibration head housing and communicating with the housing opening. The power/control box may be configured to induce emission of an acoustic calibration signal from the speaker of the calibration head.

Abstract: The invention relates to improved methods and apparatus for performing ground vibration tests (so-called “ground vibration tests”) on an airplane. In the method according to the invention, the airplane is jacked up essentially undamped (“rigidly”) in conventional holding points with lifting devices. For purposes of the ground vibration test, the airplane is then excited to vibrate in a known manner using a plurality of vibration exciters, and the vibrations are acquired with a plurality of measuring transducers, in particular accelerometers. A dynamic vibration model of the airplane theoretically calculated beforehand can here be adjusted. The boundary conditions are removed during or after the ground vibration test, meaning the influence of the lifting device is “mathematically canceled out”, so that the determined measured values reflect the so-called “free-free” state of the airplane, as if the airplane had actually been in free flight during the ground vibration tests.

Abstract: A mounting pedestal is designed to hold a DUT in position for both electrical testing and vibration testing. The design is such that the pedestal can remain thermally sealed from an environment created within a confined area so as to impart vibration to a DUT positioned within the environmentally protected area, the vibration coming from a vibrator outside the environmentally sealed area. The pedestal, in one embodiment, extends through the base of a DUT holding tray while still preserving the environment within the sealed area. In one embodiment, the pedestal can position the DUT in any of several selected orientations.

Abstract: One embodiment of the present invention provides a system that generates vibration-resistance signatures for hard disk drives (HDDs). In this system, a set of HDDs is mechanically affixed to a disk enclosure. The system additionally includes a vibration generator which is mechanically coupled to the disk enclosure and can apply a translational vibration profile to the disk enclosure. The system further includes a coupling mechanism between the set of HDDs and the disk enclosure which translates the translational vibration profile into both translational and rotational vibrations for the set of HDDs in multiple dimensions. The system additionally includes a monitoring mechanism which monitors an HDD performance metric from the set of HDDs while the HDDs are subject to the translational and rotational vibrations. The system also includes a signature-generation mechanism which uses the monitored HDD performance metric to generate vibration-resistance signatures for the set of HDDs.

Abstract: An apparatus and a process for determining the mass required for a wire damper ring to produce the maximum amount of damping in a certain rotary machine. The testing apparatus includes a test piece with an inward facing annular groove and a plurality of expander segments each with the top or outer half of a wire damper ring segment secured to and extending outward to fit within the annular groove. A mandrel with an outer surface having a slight slope is passed through a central opening of the expander segments and displaces the ring segments radially outward and into the annular groove at varying loads. The apparatus is set to vibrating and a piece of the test piece is observed for vibrations. The load applied to the damper ring segments is varied until the vibration is at a minimum. The applied load can now be correlated with the mass required for the damper ring to produce similar damping capability.

Abstract: A triaxial vibration composite testing apparatus including a working tabletop, wherein the second axial vibration transmission mechanism in the horizontal X axial direction and the third axial vibration transmission mechanism in the horizontal Y axial direction are both cross linear guide pairs; the first axial vibration transmission mechanism in the perpendicular Z axial direction includes an upper and a lower clamps and a central panel, the upper and the lower clamps being horizontally opposite to each other up and down, the central panel being positioned between the upper and the lower clamps, the upper and the lower clamps oppositely clamping the central panel; a gap fit between the lower surface of the upper clamp and the upper surface of the central panel forms an upper fit plane, and a gap fit between the upper surface of the lower clamp and the lower surface of the central panel a lower fit plane; and the high pressure oil is pumped into the upper fit plane gap and the lower fit plane gap to form a hy

Abstract: A jig device usable with a flat display panel which includes a frame including a base frame having an opening and a vertical frame which extends vertically along a perimeter of the base frame and a supporting frame coupled to the base frame within the frame, on which the flat display panel is disposed, wherein the supporting frame includes fixing portions provided at corners thereof to support respective corners of the flat display panel.

Abstract: A sonotrode for accelerating shot for ultrasonic shot peening, includes at least one vibration exciter and a cover element that has an output side of the sonotrode, wherein the cover element is to be operated by means of the vibration exciter with a forced vibration such that the value of the vibration amplitude of the cover element corresponds essentially to the value of the vibration amplitude of the vibration exciter, where from this cover element another cover element is set out on the further side of the vibration exciter and in which between these two cover elements is stretched a majority of spring elements in the form of tension springs.

Abstract: A method of testing a haptic device that includes an actuator and has a first weight includes placing the haptic device on a test fixture that has a second weight that is greater than the first weight. The haptic device is placed on the test fixture so that the actuator within the haptic device is substantially close to the center of gravity of the test fixture. The method further includes causing the haptic device to generate haptic effects via the actuator, and measuring the acceleration of the test fixture during the haptic effects.

Abstract: A testing apparatus and method comprising providing a platform for a unit under test, charging a capacitor bank with a charging system, with a switching and power control system generating multiple pulses per cycle from energy from the capacitor bank, and with an electromagnetic force generator receiving pulses from the switching and power control system and directing force at the platform.

Abstract: A vibration test apparatus is disclosed. The vibration test apparatus includes a platform assembly, which receives a vibration input from a vibration source and imparts a multi-axial vibration to a test specimen on the platform assembly. In illustrated embodiments the platform assembly includes one or more platforms having an adjustable incline angle. The incline angle is adjusted to provide the desired output vibration based upon a measured or determined vibration profile and the input vibration from the vibration source.

Abstract: A vibration table for testing products employs threaded inserts for mounting the test products or fixtures therefor on the table. The threaded inserts have enlarged and elongated threaded shafts that engage threaded openings in the upper surface of the table, with enlarged heads on the inserts being positioned adjacent the outer surface of the table or the outer surface of an insulation layer mounted on the table. The inserts have elongated internally threaded openings therein, to which the test products or fixtures are bolted by elongated bolts. The inserts enhance the transmission of vibration forces to the test product with or without an insulating layer. They also provide improved temperature uniformity by providing air circulation between the test product and the table.

Abstract: A vibration state detecting method at a machining stage of a work and/or tool, includes the steps of mounting the work and/or tool on a predetermined rotational device and measuring a deviation size and/or deviation average speed corresponding to each rotational number of the work and/or tool; presetting the deviation size and/or the deviation average speed measured by using the rotational device, a vibration amplitude and/or vibration average speed when each machine tool having a work and/or tool mounted thereon is rotated, with a common unbalance amount and at a rotational speed, and proportional fixed number of both thereof; and calculating a vibration amplitude and/or vibration average speed corresponding to each number of rotations when the work and/or tool is mounted on each machine tool by using a measurement value of the deviation size and/or deviation average speed of using rotational device, and the proportional fixed number.

Abstract: The invention relates to an improved method for a ground vibration test (so-called “ground vibration test”) on an airplane. In the method according to the invention, the airplane is jacked up essentially undamped (“rigidly”) in conventional holding points with lifting devices. For purposes of the ground vibration test, the airplane is then excited to vibrate in a known manner using a plurality of vibration exciters, and the vibrations are acquired with a plurality of measuring transducers, in particular accelerometers. A dynamic vibration model of the airplane theoretically calculated beforehand can here be adjusted. The boundary conditions are removed during or after the ground vibration test, meaning the influence of the lifting device is “mathematically canceled out”, so that the determined measured values reflect the so-called “free-free” state of the airplane, as if the airplane had actually been in free flight during the ground vibration tests.

Abstract: The invention relates to a reaction chamber system (10, 70) for processing samples, comprising a reaction chamber (12), a sample carrier (26) arranged at least in the reaction chamber (12). When in operation, said sample carrier can be displaced in relation to the reaction chamber (12) by means of a drive device (30) which is coupled to the sample carrier (26). The reaction chamber system also comprises heating means (50) for warming the samples. The invention is characterized in that the heating means (50, 54) are arranged on the sample carrier (26) and can be displaced with the sample carrier (26) when in operation.

Abstract: An apparatus (500) for fatigue testing elongate test articles (404) including wind turbine blades through forced or resonant excitation of the base (406) of the test articles (404). The apparatus (500) includes a testing platform or foundation (402). A blade support (410) is provided for retaining or supporting a base (406) of an elongate test article (404), and the blade support (410) is pivotally mounted on the testing platform (402) with at least two degrees of freedom of motion relative to the testing platform (402). An excitation input assembly (540) is interconnected with the blade support (410) and includes first and second actuators (444, 446, 541) that act to concurrently apply forces or loads to the blade support (410). The actuator forces are cyclically applied in first and second transverse directions. The test article (404) responds to shaking of its base (406) by oscillating in two, transverse directions (505, 507).

Abstract: In a preferred embodiment, a vibrator table apparatus includes a primary table member driven by at least two vibrators, having upper and lower surfaces and defining x and y axes. The improvement of this embodiment includes at least one of the upper and lower surfaces of the primary table member defining an opening for each of a first plurality of substantially parallel channels and an opening for each of a second plurality of substantially parallel channels substantially perpendicular to the first plurality of channels.

Abstract: A vibration test device for an electronic device(40) includes a test platform (10), and at least a pair of holders (20) attached to the platform. The test platform is capable of vibrating along any predetermined direction, and at any predetermined frequency. Each of the holders includes a pair of parallel base brackets(22) attached to the platform, and a mounting bracket(24) attached to the base brackets for mounting the electronic device. The holders and the electronic device are capable of vibrating together with the test platform.

Abstract: The problems inherent with connecting a DUT to a test station have been solved by the use of a tray designed to allow a wide variety of different DUTs to be physically connected individually to a test station using a universal test station connector. The tray allows for the association therewith of a personality module which serves to provide the proper physical connections and to electrically condition the test station to the electrical characteristics of the DUT. The tray allows for sealed environmental testing of the DUT without impacting any physical connections between the DUT and the test station. The tray also allows for the DUT to be vibrated from externally applied motion without interfering with either the sealed environment around the DUT and without imparting motion to the physical connection between the DUT and the test station.

Abstract: The invention relates to methods of measuring an aircraft under simulated flight-loads while the aircraft is not in-flight. While the aircraft is under the simulated flight-loads, positions of one or more portions of the aircraft may be measured in order to determine how the aircraft is performing under such loads. The aircraft may be readjusted and/or redesigned based on the measurements in order to reduce drag on the aircraft.

Abstract: A sonotrode for accelerating shot for ultrasonic shot peening, includes at least one vibration exciter and a cover element that has an output side of the sonotrode, wherein the cover element is to be operated by means of the vibration exciter with a forced vibration such that the value of the vibration amplitude of the cover element corresponds essentially to the value of the vibration amplitude of the vibration exciter, where from this cover element another cover element is set out on the further side of the vibration exciter and in which between these two cover elements is stretched a majority of spring elements in the form of tension springs.

Abstract: A method for calculating material properties of a material includes determining a dilatational wavespeed and a shear wave speed. The dilatational wavespeed is determined by conducting vertical vibration tests of two specimens of the material, one specimen being twice as thick as the other. Transfer functions are obtained from these tests and used to calculate the dilatational wavespeed. The shear wavespeed is determined by conducting horizontal vibration tests of two specimens with one specimen being twice as thick as the other. The shear wavespeed can be calculated from transfer functions obtained from these tests and the dilatational wavespeed. Other material properties can be calculated from the dilatational and shear wavespeeds. Frequency dependence of the properties can be determined by conducting the tests at different frequencies.

Abstract: A vibration table for testing products employs threaded inserts for mounting the test products or fixtures therefor on the table. The threaded inserts have enlarged and elongated threaded shafts that engage threaded openings in the upper surface of the table, with enlarged heads on the inserts being positioned adjacent the outer surface of the table or the outer surface of an insulation layer mounted on the table. The inserts have elongated internally threaded openings therein, to which the test products or fixtures are bolted by elongated bolts. The inserts enhance the transmission of vibration forces to the test product with or without an insulating layer. They also provide improved temperature uniformity by providing air circulation between the test product and the table.

Abstract: A method for calculating material properties of a material includes conducting two insertion loss tests of the material having a single thickness and a double thickness. These tests are conducted at a zero wavenumber. Utilizing these insertion loss tests, a dilatational wavespeed is computed. The method continues by calculating a shear wavespeed by performing three insertion loss tests of the material at single, double and triple thicknesses. These tests are conducted at a non-zero wavenumber. A shear wavespeed can be calculated from the dilatational wavespeed and these insertion loss tests. Lamé constants, Young's modulus, Poisson's ratio, and the shear modulus for the material of interest can then be calculated using the dilatational and shear wavespeeds.

Abstract: In a preferred embodiment, a vibrator table apparatus includes a primary table member driven by at least two vibrators, having upper and lower surfaces and defining x and y axes. The improvement of this embodiment includes at least one of the upper and lower surfaces of the primary table member defining an opening for each of a first plurality of substantially parallel channels and an opening for each of a second plurality of substantially parallel channels substantially perpendicular to the first plurality of channels.

Abstract: A vibration test device for an electronic device (40) includes a test platform (10), and at least a pair of holders (20) attached to the platform. The test platform is capable of vibrating along any predetermined direction, and at any predetermined frequency. Each of the holders includes a pair of parallel base brackets (22) attached to the platform, and a mounting bracket (24) attached to the base brackets for mounting the electronic device. The holders and the electronic device are capable of vibrating together with the test platform.

Abstract: A shaker assembly for shaking a tested component. The shaker assembly permitting a vibration to be induced within the tested component, such as for use in measuring operating characteristics of the tested component.

Abstract: A vibration test apparatus is disclosed. The vibration test apparatus includes a platform assembly, which receives a vibration input from a vibration source and imparts a multi-axial vibration to a test specimen on the platform assembly. In illustrated embodiments the platform assembly includes one or more platforms having an adjustable incline angle. The incline angle is adjusted to provide the desired output vibration based upon a measured or determined vibration profile and the input vibration from the vibration source.

Abstract: The problems inherent with connecting a DUT to a test station have been solved by the use of a tray designed to allow a wide variety of different DUTs to be physically connected individually to a test station using a universal test station connector. The tray allows for the association therewith of a personality module which serves to provide the proper physical connections and to electrically condition the test station to the electrical characteristics of the DUT. The tray allows for sealed environmental testing of the DUT without impacting any physical connections between the DUT and the test station. The tray also allows for the DUT to be vibrated from externally applied motion without interfering with either the sealed environment around the DUT and without imparting motion to the physical connection between the DUT and the test station.

Abstract: A system for inducing shock may include a first slap plate attached to a shaker armature of a shaker table system to impart a shock to any object being tested by the system. The shock is amplifiable by use of the first slap plate compared to the object being coupled to the shaker armature without the first slap plate. The system may also include a specific attachment arrangement for attaching the first slap plate to the shaker armature. The specific attachment arrangement and a configuration of the first slap plate may be selected to control a level of shock imparted to the object being tested.

Abstract: The invention relates to an improved method for a ground vibration test (so-called “ground vibration test”) on an airplane. In the method according to the invention, the airplane is jacked up essentially undamped (“rigidly”) in conventional holding points with lifting devices. For purposes of the ground vibration test, the airplane is then excited to vibrate in a known manner using a plurality of vibration exciters, and the vibrations are acquired with a plurality of measuring transducers, in particular accelerometers. A dynamic vibration model of the airplane theoretically calculated beforehand can here be adjusted. The boundary conditions are removed during or after the ground vibration test, meaning the influence of the lifting device is “mathematically canceled out”, so that the determined measured values reflect the so-called “free-free” state of the airplane, as if the airplane had actually been in free flight during the ground vibration tests.

Abstract: Provided herein is an apparatus for detecting vibrations in a machine tool having a rotor portion (2) which is provided with tool members (5) and defines an axis of rotation (2a), the apparatus comprising a sensor assembly (3) which is able to rotate together with the rotor portion (2) and is designed to issue signals correlated to the vibrations, and a supporting and amplification device (6) for supporting the sensor assembly (3) and for amplifying the vibrations, which is set between the sensor assembly (3) and the rotor portion (2) and has a rotational asymmetry about the axis of rotation (2a) for any angle smaller than a full circle.

Abstract: Soft support systems and methods for dynamically testing structures are disclosed. In one embodiment, a soft support system adapted to decouple a structure from a support surface for dynamic testing includes a containment bag, an inflatable chamber disposed at least partially within the containment bag and adapted to engage with a portion of the structure, the inflatable chamber being further adapted to exert a lifting force on the portion of the structure during inflation of the inflatable chamber, and an inflator module coupled to the inflatable chamber and adapted to facilitate inflation of the inflatable chamber within the containment bag. In one embodiment, the inflatable chamber comprises a toroidally-shaped inflatable member defining a central opening adapted to at least partially receive a portion of the structure during inflation of the inflatable chamber.

Abstract: A sliding vibration-resisting building model includes a vibration machine having a vibration table provided thereon with a model base. Two vibration-resisting devices are fixed on the model base, and a model chassis is secured on the two vibration-resisting devices and a model testing structure is assembled on the model chassis. The vibration-resisting devices are able to lower the vibration of the model testing structure when the vibration machine carries out simulating earthquakes and reduce the energy received by the structure, able to elevate the vibration resistant strength of buildings.

Abstract: A method and apparatus for simultaneous fracture and fatigue testing of a semiconductor wafer which includes installing an array of cantilever beams on the wafer, wherein each of the cantilever beams includes a proof mass; mounting the wafer on a base; actuating the base at a predetermined rate of motion causing a displacement of the proof mass; and measuring the displacement. The actuating causes the array to oscillate in a direction perpendicular to the wafer, wherein the displacement of the proof mass is generally perpendicular to a plane of the wafer. Alternatively, the actuating causes the array to rotate around a center of the array, wherein the displacement of the proof mass is generally parallel to a plane of the wafer. The displacement is a function of mechanical stress and strain in the cantilever beams, wherein the mechanical stress and strain causes any of fracture and fatigue of the cantilever beams.

Abstract: A single axis vibration test system includes a vibration force generator or “shaker” which can be used with a head expander, and separate pairs of hydrostatic self-aligning sliding bearings connecting two large reaction masses to the head expander. Preload forces are applied by separate preload pistons supported on a preload ring surrounding the shaker. Preload forces are transmitted by the preload ring to the sliding bearings to clamp the head expander directly to the reaction masses, which resists lateral and rotational motions during vertical axis testing. The reaction masses are supported on resilient supports carried on a sub-structure rigidly affixed to ground, for avoiding a rigid connection between the preload ring and ground which in turn avoids unwanted mechanical resonances within the operational frequency range of the system during use.

Abstract: A control system for a failure mode testing system is described. The control system employs at least one control algorithm that enables the testing system to be operated at optimal pressure and frequency levels in order to generate a desired system response, such as a desired energy level and desired slope of the fast Fourier transform of the system response. Also described are a pressure dither system and a frequency ringing system for enhancing the operation of the actuator cylinders of the failure mode testing system. All three of the systems can be incorporated, either singularly or in combination, into a computer software program that can be employed to operate and control the failure mode testing system.

Abstract: A control system for a failure mode testing system is described. The control system employs at least one control algorithm that enables the testing system to be operated at optimal pressure and frequency levels in order to generate a desired system response, such as a desired energy level and desired slope of the fast Fourier transform of the system response. Also described are a pressure dither system and a frequency ringing system for enhancing the operation of the actuator cylinders of the failure mode testing system. All three of the systems can be incorporated, either singularly or in combination, into a computer software program that can be employed to operate and control the failure mode testing system.

Abstract: The vibrating device comprises, a vibrating table 3 vibrating upwards and downwards with respect to a vibrating platform 2, and a lower side installation section 4 provided on the vibrating table 3 and having a hemispherical recess surface for supporting the lower end section of a hydraulic shock absorber 6. It further comprises: a holding section 5 for pressing and holding the hydraulic shock absorber 6 towards the vibrating table 3; and an upper side installation section 8 for supporting the front end of the piston rod 7 of the hydraulic shock absorber 6. Moreover, the vibrating device further comprises: a universal joint 30 for coupling the vibrating table 3 and the vibrating platform 2, and a restricting member 31 for restricting the movement of the universal joint 30.

Abstract: An earthquake simulating vibration table includes a vibration machine having a vibration table provided on the topside. Paper models are assembled on a model fundamental base that is fixed on the vibration table. The vibration machine is controlled by a computer to produce simulated various-degree earthquakes. A test of anti-seismic strength of the paper models begins with a smallest seismic strength and then the seismic strength increases by degrees until it reaches to a largest level to have all the paper models collapse. The earthquake simulating vibration table is convenient and quick in assembling, economical in cost and able to be popularized to schools to serve as a course of vibration resistance education to elevate students' learning interest.

Abstract: A control system for a failure mode testing system is described. The control system employs at least one control algorithm that enables the testing system to be operated at optimal pressure and frequency levels in order to generate a desired system response, such as a desired energy level and desired slope of the fast Fourier transform of the system response. Also described are a pressure dither system and a frequency ringing system for enhancing the operation of the actuator cylinders of the failure mode testing system. All three of the systems can be incorporated, either singularly or in combination, into a computer software program that can be employed to operate and control the failure mode testing system.

Abstract: A testing apparatus for use with a data storage component that includes a base platform and a retaining element coupled to the base platform. The retaining element is sized and configured to retain the data storage component. The retaining element is linearly movable relative to the base platform during a linear acceleration mode without substantial rotational movement. The retaining element is rotationally movable relative to the base platform without substantial linear movement during a rotational acceleration mode. The testing apparatus further includes an actuator disposable in mechanical communication with the retaining element for moving the retaining element relative to the base platform.

Abstract: An apparatus for controlling motion of an object includes a first actuator for moving the object, an elastic-motion measuring unit for measuring elastic motion of the object, and a control unit for controlling the first actuator based on a result of measurement of the elastic-motion measuring unit. Another apparatus for controlling motion of an object includes a first actuator for moving the object, a second actuator for suppressing elastic motion of the object, and a control unit for controlling the second actuator based on a result of predicting the elastic motion of the object caused by the first actuator.

Abstract: A high thermal change rate of test apparatus aims to realize test equipment requirement of highly accelerated life test(HALT) and highly accelerated stress screening(HASS). Structurally, the apparatus is provided with a cabinet body with an interior for placing test specimen. The cabinet body is provided with elements of fans, electric heating tubes and liquid nitrogen nozzles therein. The positions of the cabinet body and the control system are separate. Several groups (normally 2 or 3 groups, depends on the size of cabinet) of liquid nitrogen pipes connecting the cabinet body are flexible stainless steel pipes for enclosing and insulating sleeve tubes. During full-speed temperature cooling, all groups of the pipes simultaneously eject liquid nitrogen. When temperature is constant, only one group of liquid nitrogen pipe with cryogenic valve and nozzles is used and micro-adjusted to achieve good temperature stability.

Abstract: A vibration test machine comprises a stationary outer frame, a shake table in the form of a mass to which vibration energy is transmitted inside the outer frame, a driven preload piston supported by the outer frame and coupled to one side of the shake table, a passive preload piston supported by the outer frame and coupled to the shake table on a side opposite from the driven preload piston, and an external force generator external to the outer frame and coupled to the driven piston for inducing high frequency vibrational energy to the driven piston which, in turn, transmits that vibration energy to the shake table. In one embodiment, a multiple degree of freedom shaker comprises multiple exterior force generators each coupled to a corresponding driven preload piston having a related passive preload piston on a opposite side of the shake table.

Abstract: The closed-form HEAD EXPANDER comprises a table surface; one end of each edge surface having a curved side; a trumpet body with a plurality of cambered surfaces downwards reduced from the curved side; an outer annular supporter and an inner annular supporter being connected to and support the trumpet body so as to form a first receiving space and a second receiving space; a plurality of spacing ribs being formed within the inner annular supporter; the plurality of spacing ribs being connected to a central shaft; a plurality of long grooves being formed between the inner annular supporter, the spacing ribs, the central shaft, and a table bottom; and a plurality of cambered sloped surfaces being formed on the surface of the trumpet body and connected to the inner annular supporter and the curved sides so as to equally space the surface of the trumpet body.

Abstract: The present invention provides a HALT/HASS fixturing table for generating secondary vibration using moving balls and multi-axes rails comprising a lower panel having on the top surface thereof a plurality of horizontal rails and vertical rails formed in the shape of grooves, moving balls inserted in the horizontal rails and the vertical rails of the lower panel to move in the horizontal and the vertical rails, a buffering member placed on the lower panel, and a upper panel placed on the buffering member, a specimen for the HALT/HASS test being attached to the upper panel.