Method for non-destructive testing of physical condition of buildings and structures

FIELD: construction.

SUBSTANCE: in a drilled well under a building or a structure, or in the vicinity thereof, a high pressure hose is set, muffled at one end and connected to the hydrostatic generator with the other end. Adjustable vibro pulse impact on the ground under the building is created by changing the working fluid pressure supplied to the high pressure hose. Oscillations of the building or the structure are recorded by three-component vibration sensors installed near the tested object or inside it. The conclusion on the physical condition of the building or the structure is carried out by comparing the measured dynamic characteristics of the building or the structure before and after the vibro pulse impact.

EFFECT: improved assessment accuracy of the physical condition of the building or structure under vibro pulse impact on the surrounding ground.

3 cl, 1 dwg

 



 

Same patents:

FIELD: machine building.

SUBSTANCE: invention relates to vibration equipment. Method suggests the vibrator use, in it the piezoelement is made as package of the piezoceramic rings, at that inside the rings a cylindrical mandrel is installed. Axis of symmetry of the mandrel is located perpendicularly to the base, and disk is located in it top part such that it is contact with the top piezoceramic ring of the package of the piezoceramic rings of the piezoelement, and on the top surface of the disk the measuring piezoelements are installed, they are in contact with two-step cylindrical disk, tip is connected in its top part. The disk OD is made equal to OD of the package of the piezoceramic rings, and base is rectangular plate with four slots to secure to the studied object. At that the bottom plane of the cylindrical mandrel is located with gap in relation to the top plane of the base, and current conducting casing is made in form of the cylindrical shell. In top deformed part of the base the strain sensors are glued, and in the cylindrical mandrel the cavity is made and filled by the elements creating additional stochastic motion.

EFFECT: extension of frequency range of the vibration accelerations.

2 dwg

FIELD: measurement equipment.

SUBSTANCE: method to inspect tightening of an electric machine stator core, where the machine comprises a core (2) of the stator and a rotor (3), forming an air gap (5) between each other, besides, the method includes stages, when they introduce an inspection device (12), which is connected with a movable support (10), into the air gap (11) they introduce a plate (21) between steel sheets (5) of the stator core, and the plate (21) is put in rotation, the inspection device (12) is installed locally, and local inspection of certain zones of the generator stator core (2) is carried out. The device to realise the method, comprising a movable support (10), introduced into the air gap (11) between the stator core (2) and the rotor (3), the plate (21) put in rotation between steel sheets (5) of the core, and the inspection device (12), installed on the movable support (10).

EFFECT: performance of inspection to determine tightening of a stator core without necessity to extract a rotor with the help of a proposed method and a device, and also reduced risk to damage a stator core and/or rotor as a result of inspection.

8 cl, 6 dwg

FIELD: measuring instrumentation.

SUBSTANCE: mechanical wave converter includes lighting, water tank with mirror unit, and stand supporting photosensitive element. Lighting is installed on damper at an angle towards vertical. Beams of lighting fall onto mirror unit in the water tank and reflect from it to photosensitive element mounted on Textolite stand. Sensitive area size in the photosensitive element is selected equal to the size of light spot of reflected light.

EFFECT: enhanced sensitivity and reliability of device.

1 dwg

FIELD: test equipment.

SUBSTANCE: test bench for vibration test of a back sight contains a vibration exciter with a table, the device for placement of the tested product having a shape of cube with a cover which is rigidly fastened to the table of the vibration exciter. On external surfaces of the cube windows for electric sockets, the back sight lens, and stiffening ribs are made, in the top part of the cube two guides with grooves are located, with form a truncated prism, the cube cover is designed as a plate - the object simulator to which the back sight is fixed, and there is a ledge interacting with grooves of the guides. In the specific case for restriction of longitudinal movements and forces acting on plate fasteners - the object simulator, the contacting surfaces of the plate holes - the object simulator and fasteners are made with the cone slope, equal to 2.

EFFECT: improvement of accuracy of measurement of vibrotransfer overloads in the required range of frequencies of a back sight by increase of rigidity of a test bench structure.

2 cl, 6 dwg

FIELD: measurement equipment.

SUBSTANCE: invention relates to the field of continuum mechanics and is intended for assessment of the stress and strain state of elements of mechanical systems. The method consists in measurement of spatial vibration, accumulation of an array of vector values of strains and reproduction of the measuring point spatial hodograph. Meanwhile synchronously with measurements the analytical synthesis of 3D-superposition of the spectrum of measurements is performed and the array of vector values of tensions is accumulated. The diagnostics of stress and strain state of the object is performed using the visual image, represented as a spatial three-dimensional diagram of physical state of the monitored object in the measurement point representing related Hooke and Poisson laws.

EFFECT: implementation of a possibility of real time reflecting of current resource of structural strength of monitored object, improvement of reliability of assessment of physical condition of monitored objects.

5 dwg

FIELD: test equipment.

SUBSTANCE: invention refers to test equipment and can be applied in various industries for vibration resistance tests in three mutually perpendicular directions. Device includes vibrator with table bearing a fixture for test object fixation. The fixture allows for test object re-orientation and fixation in three mutually perpendicular directions without object dismounting. Fixture case features two mobile frames, one mounted in the other, with mutually perpendicular rotation axes, so that the frames can turn by 90 around the axes, and each frame has a device for locking after re-orientation in the form of disc brake and wedge clamp. Internal frame includes a unit for torque transmission from a drive to the object. Vibrator base features a portal in the form of rack and support, its horizontal beam bearing two rollers on brackets, with roller output shaft pulley connected in series with work pulley of the device for tests in dynamic mode of object.

EFFECT: possible vibration resistance test in three mutually perpendicular directions without object dismounting, enabled testing of articles in static and dynamic modes of the object state.

13 dwg

FIELD: measurement technology.

SUBSTANCE: fibre optic vibration transducer comprises a support base, a vibration element, the optical lightguides relative to the ends of which at a distance the reflecting surface is formed, each of the optical lightguides performs simultaneously the function of supply and removal of the light flux, the support base from the monocrystal plate is made integrally with the vibration element, at the top and bottom of the support base the lightguides are fixed, which axes are perpendicular to the reflecting surface. The extensions of the axes of the said lightguides cross its upper and lower bounds.

EFFECT: improved accuracy, reliability and service life of the fibre optic vibration transducer and sensors, meters, in which structure it is used.

3 cl, 7 dwg

FIELD: physics, acoustics.

SUBSTANCE: invention relates to acoustics and is intended to generate acoustic waves in a gaseous medium. A method of generating the acoustic waves is carried out by forming an oscillatory body from a cloud of ionised gas in an electrostatic field with subsequent simulation of the oscillatory body with a high-frequency electric field, wherein the electrostatic field used is an alternating electric field. The apparatus for implementing the method comprises two acoustically transparent electrodes 1, divided by a dielectric housing 2, having a cavity 3, which forms with the electrodes 1 an ionising chamber, an ionising electrode 4, a dc voltage source 5 and a voltage modulator 6.

EFFECT: invention enables to generate acoustic waves in a wide frequency and power range.

2 dwg

FIELD: instrumentation.

SUBSTANCE: proposed process comprises application of transducer of analysed object integrity arranged directly thereat and remote transducer space from said object. Oscillations from external sources are recorded at said objected and at a distance therefrom. Additionally, oscillations at analysed object and at the distance therefrom are recorded at a time. Said transducer of integrity and remote transducers are oscillation transducers with identical characteristics. Distance from analysed object to remote transducer is selected not larger than seismic wavelength from external source and so that oscillation amplitudes at remote transducer location are negligibly small compared with those of analysed object. Oscillation control system allows for difference between readings of both said transducers at seismic effects from external sources. Complex comprises aforesaid transducers and object oscillation control system. Said transducer of integrity and remote transducers are oscillation transducers with identical characteristics. Distance from analysed object to remote transducer is selected not larger than seismic wavelength from external source and so that oscillation amplitudes at remote transducer location are negligibly small compared with those of analysed object. Oscillation control system allows for difference between readings of both said transducers at seismic effects from external sources.

EFFECT: higher reliability, possibility to rule out misoperations, simplified design.

4 cl, 1 dwg

FIELD: machine building.

SUBSTANCE: proposed method comprises measurement of vibration at the machine body info point, isolation of vibration component inherent in the machine mechanism under analysis to estimate machine parameters to be used in decision on technical state. Note here that vibration characteristic function is measured to estimate its integral characteristic representing an area under the curve of characteristic function modulus so that its proximity to zero allows defining the mechanism degradation.

EFFECT: higher validity of diagnostics.

3 dwg, 1 tbl

FIELD: testing engineering.

SUBSTANCE: central excited pillar of the device is secured to the table of the vibration bench. The side loaded pillars are secured to the corresponding bearing strips of the vibration insulators. The second bearing strips are secured to the central pillar. The loaded side pillars and shelves are provided with slots for changing position of the vibration insulators depending on their sizes. The exciting force is directed along the axis of the vibration insulator and transmitted through excited central pillar and strips to the flexible member of vibration insulators which undergo shearing vibration energy and reduce the exciting force transmitted to the loaded weight through side pillars.

EFFECT: enhanced reliability of testing.

6 dwg

FIELD: testing equipment.

SUBSTANCE: method includes mounting construction on a sand, fixing its ends according to operation conditions, exciting oscillations in non-loaded construction, measuring main frequency and decrement of free or forced oscillations, while excitation of transverse and longitudinal forced oscillations is performed concurrently at resonance frequency at given level of oscillations energy, vibro-graph of amplitude-modulated oscillation process is recorded and used to determine amplitude modulation coefficient. Received data are compared to appropriate dynamic parameters, received for standard construction of given type with same control modes and holding conditions. Quality coefficients of controlled part are determined on basis of comparison.

EFFECT: higher trustworthiness, higher reliability, higher efficiency.

2 cl, 3 dwg

FIELD: mechanical engineering.

SUBSTANCE: method allows determining of resonant frequency, Q-factor, amplitude of stationary oscillations of object and level of exciting influence during exploitation without making influence onto mode of operation of object, without stops and delays at resonant frequencies. Method also allows determining all the factors mentioned above during process of starting and stopping. Procedures of the method can be easily automated for making measurements which results to reduce time and qualification of explorer for measuring necessary parameters. Resonant frequency area (fl, fu) of object is selected. During operation, when object is subject to exciting influence, frequency of exciting influence and parameter of oscillations of object are measured and registered as function of time F(t) and x(t) under the condition that the frequency of exciting influence belongs to resonant frequency area (fl, fu) and is close to permanent level of exciting influence. Value of exciting influence E0, amplitude of stationary oscillations Ap, resonant frequency fp and q-factor are judged from registered values of exciting influence frequency F(t) and parameter of oscillations of object x(t).

EFFECT: reduced chance of damage during operation.

5 cl, 2 dwg

FIELD: measuring equipment.

SUBSTANCE: allowed level of exciting effect is determined using given speed of frequency alternation with passing of resonance area for exciting object at resonance frequency. Harmonic exciting effect is set to be not more than allowed level. frequency of exciting effect is set to be equal to lower or upper value of resonance area frequency. frequency of exciting effect is increased or decreased with given speed of frequency alternation. frequency of exciting effect is measured and registered as well as parameters of object movement as functions of time under condition of presence of exciting effect frequency within resonance frequencies area, on basis of received data value of exciting effect is estimated, as well as amplitude of stationary resonance oscillations and, resonance frequency and energy factor.

EFFECT: higher speed of operations.

4 cl, 2 dwg

FIELD: mechanical engineering.

SUBSTANCE: method includes finding resonance frequency area (fl;fu) during operation, when object is under exciting effect, parameter of object oscillations is measured and registered during operations as function of time x(t) under condition of position of frequency of exciting effect in resonance frequency area [fl;fu] and exciting effect possibly close to permanent level. On basis of registered values of parameter of oscillations of object x(t) as time function t, resonance frequency fp and quality Q are evaluated.

EFFECT: possible determining of resonance frequency and quality of object's oscillations during operation without effect on object operation mode for performing measurements, without stops and delays at resonance frequencies, to decrease possibility of breakdowns of object during operation, launch and stopping.

1 cl, 1 dwg

FIELD: testing engineering.

SUBSTANCE: method comprises emitting single frequency by means of a quartz generator, control of the bridge for measuring capacity, and detecting the frequency of the component. The device comprises generator, detector, and receiving circuit that has balancing bridge for measuring capacity. The capacitive probe comprises quartz generator and receiving circuit that has balancing bridge for measuring capacity.

EFFECT: enhanced accuracy.

19 cl, 2 dwg

FIELD: measurement technology.

SUBSTANCE: electric signal, which is proportional to object's vibration, is converted to spectrum. Amplitude components are memorized, the memorized values are compared with critical and estimation levels and after that condition of object is determined and indicated. Simultaneously with measurement and memorizing of basic signal, meanings of signals of accompanying factors are measured and memorized as well as temperatures of diagnosed object and environment temperature. Then the values are compared with corresponding critical and estimation levels with ones preset before. Diagnostics with diagnosis "not available for operation" is stopped when values of signals of accompanying factors simultaneously exceed critical levels and when components of main signal exceed estimation levels. Technical condition is determined and trouble-free operation time of object to be diagnosed is predicted when values of components of main signal and values of signals of accompanying factors do not exceed corresponding critical values.

EFFECT: reduced time; improved truth of results; higher reliability.

1 dwg

FIELD: mechanical engineering.

SUBSTANCE: vibration bench comprises base provided with vertical pillars whose top parts are interconnected through cross-piece, vibration generator, and loading device. The vibration bench additionally has hydrostatic bearings made in the base and cross-piece and composed of three balls uniformly arranged over periphery and interacting with three hydrostatic thrust bearings. The vibration generator is made of electric motor, gear box with step-up and step-down gears, double eccentric, and shackle connected with the end of rocker. The loading device is composed of disks mounted on the rod.

EFFECT: simplified structure and enhanced precision.

1 dwg

FIELD: mechanical engineering.

SUBSTANCE: bench comprises base provided with vibration generator and loading device. The base also has lever whose one end is pivotally connected with the base and other end is connected with reduction gear and drive through crank and double eccentric. The strain-gage dynamometer underlies the vibration insulation. The seismic sensor is secured to the lever and records the level of the input vibration acceleration. The signals from the pickup and strain-gage dynamometer are fed to the strain-gage amplifier and then to oscilloscope, magnetograph, and computer for processing information obtained.

EFFECT: enhanced accuracy and simplified structure.

1 dwg

FIELD: measurement engineering.

SUBSTANCE: electric signal, being proportional to object's vibration, is conversed into spectrum. Amplitude components of spectrum are memorized and are subject to comparison with preliminary specified critical and evaluation levels. Technical condition is determined from results of comparison and period of non-failure operation of object being tested is determined. Prior to beginning of measurement of main signal, values of signals of associate factors are measured and memorized, namely period of actual operation of object and average meaning of environment temperature during actual operation of object. After that values of preliminary specified critical and evaluation levels of amplitude components are subject to correction depending on meanings of preliminary measured signals of associate factors.

EFFECT: improved truth of diagnostics.

1 dwg

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