Structural inspection using multitone steady-state excitation

Abstract

Various frequencies of steady-state excitation of the structure can be tested by sweeping a range of excitation frequencies. Partial measurements of the response in the structure at different excitation frequencies can be used to select the excitation frequency, and the structure can be inspected using the selected excitation frequency.

Description

Technical Field

[0001] Statement Regarding Federal Rights The United States Government has certain rights in this invention pursuant to Contract No. 89233218CNA000001 between the United States Department of Energy and TRIAD National Security, LLC for the operation of Los Alamos National Laboratory. Parties to the Cooperative Research Agreement

[0002] The research work described herein was performed under a Cooperative Research and Development Agreement (CRADA) between Los Alamos National Laboratory (LANL) and Chevron under the LANL-Chevron Alliance, CRADA number LA05C10518.

[0003] This disclosure generally relates to the field of inspecting structures using multi-tone steady-state excitation of the structures.

Background Art

[0004] Defects within a structure can be identified using steady-state wave field measurements of the structure. However, in such inspections of structures, defects smaller than the order of the wavelengths used may not be identified. Transient wave field measurements of a structure can be used to identify such small defects, but transient wave field measurements of a structure can sometimes take time.

Summary of the Invention

[0005] This disclosure relates to inspecting structures. Preliminary acoustic excitations can be generated within a structure using multiple excitation frequencies. Measurements of these preliminary acoustic excitations within the structure can be obtained. A subset of multiple excitation frequencies may be selected for use in inspecting a structure based on the measurements of these preliminary acoustic excitations and / or other information. Inspection acoustic excitations can be generated within a structure using a subset of multiple excitation frequencies. Measurements of these inspection acoustic excitations within the structure can be obtained. One or more properties of a structure can be determined based on the measurements of these inspection acoustic excitations and / or other information.

[0006] A system for inspecting structures may include one or more electronic memory devices, one or more acoustic excitation devices, one or more acoustic measuring devices, one or more processors, and / or other components. The electronic memory device may store information about the structure, preliminary acoustic excitation within the structure, selection of excitation frequencies, inspection acoustic excitation within the structure, characteristics of the structure, and / or other information.

[0007] In some implementations, structures may include hollow structures, support structures, movable structures, and / or other structures. Hollow structures may include vehicles, containers, pipes, and / or other hollow structures. Support structures may include equipment, platforms, frames, cranes, beams, and / or other support structures. Movable structures may include turbine blades and / or other movable structures.

[0008] Acoustic excitation devices may be configured to generate acoustic excitations within a structure. Acoustic excitation devices may be configured to generate preliminary acoustic excitations, test acoustic excitations, and / or other acoustic excitations within a structure. Preliminary acoustic excitations may be generated within a structure using multiple excitation frequencies. Test acoustic excitations may be generated within a structure using a subset of multiple excitation frequencies.

[0009] Acoustic measuring devices may be configured to measure acoustic excitations within a structure. Acoustic measuring devices may be configured to measure preliminary acoustic excitations within a structure, inspection acoustic excitations within a structure, and / or acoustic excitations within a structure.

[0010] A processor(s) may consist of machine-readable instructions. Executing machine-readable instructions may cause the processor(s) to prompt an inspection of a structure. A machine-readable instruction may include one or more computer program components. A computer program component may include one or more of the following: preliminary excitation components, preliminary measurement components, excitation frequency selection components, test excitation components, test measurement components, characteristic components, and / or other computer program components.

[0011] Preliminary excitation components may be configured to generate preliminary acoustic excitations within a structure. These preliminary acoustic excitations can be generated within the structure using acoustic excitation devices. Multiple excitation frequencies may be used to generate preliminary acoustic excitations within the structure. In some implementations, preliminary acoustic excitations within a structure may include preliminary steady-state acoustic excitations within the structure.

[0012] In some implementations, the structure may include steel plates with steel columns and steel plate reinforcements, and preliminary acoustic excitations may be generated by one or more transducers attached to one or more steel columns. In some implementations, the structure may include steel pipe sections, and preliminary acoustic excitations may be generated by one or more transducers attached to the steel pipe sections.

[0013] The preliminary measurement component may be configured to acquire measurements of preliminary acoustic excitations within the structure. These measurements can be obtained using acoustic measurement devices. In some implementations, the measurements of preliminary acoustic excitations within the structure may include partial measurements of the preliminary acoustic excitations within the structure. In some implementations, the measurements of preliminary acoustic excitations within the structure may include measurements of the velocity response within the structure.

[0014] The excitation frequency selection component may be configured to select a subset of multiple excitation frequencies. A subset of multiple excitation frequencies can be selected and used for inspecting a structure. The subset of multiple excitation frequencies may be selected for use in inspecting a structure based on preliminary acoustic excitation measurements and / or other information within the structure.

[0015] In some implementations, selecting a subset of excitation frequencies used to inspect a structure based on preliminary acoustic excitation measurements within the structure may include selecting a subset of excitation frequencies based on summary statistics of the structure's velocity response.

[0016] The inspection excitation component may be configured to generate inspection acoustic excitations within the structure. Inspection acoustic excitations can be generated within the structure using acoustic excitation devices. Inspection acoustic excitations can be generated within the structure using a subset of multiple excitation frequencies. In some implementations, inspection acoustic excitations within the structure may include inspection steady-state acoustic excitations within the structure.

[0017] In some implementations, the structure may include steel columns and steel plates with steel plate reinforcements, and the inspection acoustic excitation may be generated by one or more transducers attached to one or more of the steel columns. In some implementations, the structure may include steel pipe sections, and the inspection acoustic excitation may be generated by one or more transducers attached to the steel pipe sections.

[0018] The inspection and measurement components may be configured to acquire measurements of inspection acoustic excitations within a structure. Measurements of inspection acoustic excitations within a structure can be acquired using acoustic measurement devices. In some implementations, the measurements of inspection acoustic excitations within a structure may include complete measurements of the inspection acoustic excitations within the structure. In some implementations, the measurements of inspection acoustic excitations within a structure may include measurements of the velocity response within the structure.

[0019] The characteristic component can be configured to determine one or more characteristics of a structure. The characteristics(s) of the structure may be determined based on measured values ​​of test acoustic excitations within the structure and / or other information.

[0020] In some implementations, determining the characteristics(s) of a structure based on measured values ​​of inspection acoustic excitations within the structure may include (1) generating a damage map of the structure based on measured values ​​of inspection acoustic excitations within the structure, (2) generating a composite damage map from the damage map, and (3) determining the characteristics(s) of the structure based on the composite damage map and / or other information.

[0021] In some implementations, damage maps may be generated based on measurements of inspection acoustic excitations and / or filtering of other information within the structure.

[0022] In some implementations, the properties of a structure may include one or more defects within the structure. In some implementations, defects within a structure may include material additions, material losses, material cracks, and / or other defects.

[0023] In some implementations, the structural properties(s) determined based on inspection acoustic excitation within the structure may include pitting, corrosion, and / or cracking of steel plates. In some implementations, the structural properties(s) determined based on inspection acoustic excitation within the structure may include pitting, corrosion, and / or cracking of steel pipe sections.

[0024] These and other objects, features, and characteristics of the systems and / or methods disclosed herein, as well as the operation methods and functions of the related elements of the structures, the combination of components, and the economics of manufacture, will become more apparent from the following description and the appended claims, when considered in conjunction with the accompanying drawings. All of which form a part of this specification, and like reference numerals in the various figures indicate corresponding parts. However, it should be clearly understood that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limitations of the present invention. As used in this specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise.

Brief Description of the Drawings

[0025] [Figure 1] An exemplary system for inspecting a structure is shown. [Figure 2] An exemplary method for inspecting a structure is shown. [Figure 3] An exemplary processing of a damage map is shown. [Figure 4] Exemplary damage maps generated using various numbers of frequencies are shown. [Figure 5] An exemplary identification of a defect in a structure is shown. [Figure 6] An exemplary identification of a defect in a structure is shown.

Modes for Carrying Out the Invention

[0026] This disclosure relates to the inspection of structures. Various frequencies of steady-state excitation of a structure can be tested by sweeping an excitation frequency range. The excitation frequency can be selected using partial measurements of the response within the structure at various excitation frequencies, and the structure can be inspected using the selected excitation frequency.

[0027] The methods and systems of this disclosure may be implemented by and / or within a computing system, such as System 10 shown in Figure 1. System 10 may include one or more of the following components: a processor 11, an interface 12 (e.g., a bus, a wireless interface), an electronic storage device 13, an acoustic excitation device 14, an acoustic measurement device 15, and / or other components. Preliminary acoustic excitations may be generated within a structure using multiple excitation frequencies. Measurements of the preliminary acoustic excitations within the structure can be obtained by the processor 11. A subset of the multiple excitation frequencies may be selected by the processor 11 to be used for inspecting the structure based on the measurements of the preliminary acoustic excitations within the structure and / or other information. Inspection acoustic excitations may be generated within the structure using a subset of the multiple excitation frequencies. Measurements of the inspection acoustic excitations within the structure can be obtained by the processor 11. One or more characteristics of the structure may be determined by the processor 11 based on the measurements of the inspection acoustic excitations within the structure and / or other information.

[0028] The acoustic excitation device 14 may represent a device that generates acoustic excitation within a structure. Acoustic excitation of a structure may represent applying energy to the structure to generate an acoustic response within the structure. The acoustic response may represent the presence and / or propagation of one or more mechanical waves within the structure. In other words, a structure can be acoustically excited to generate mechanical waves within the structure. Mechanical waves may include waves within the audible range and / or waves beyond the audible range.

[0029] The acoustic excitation device 14 can generate acoustic excitations within a structure by applying energy to the structure mechanically (e.g., using one or more transducers), thermally (e.g., using one or more lasers), and / or by other means. For example, energy (e.g., in the form of sound, heat, ultrasound, vibration) can be applied to the structure through one or more transducers, one or more pulsed lasers, and / or other acoustic excitation devices coupled to the structure. For example, a induced wave can be generated within a plate-like structure in response to ultrasonic excitation. The ultrasonic excitation / induced wave may be sensitive to various properties of the structure. For example, the ultrasonic excitation / induced wave may be sensitive to defects (e.g., damage) within the structure, which can alter the properties of the ultrasonic excitation / induced wave at the location of the defect within the structure.

[0030] The acoustic excitation device 14 may be configured to generate acoustic excitations within a structure. The acoustic excitation device 14 may be configured to generate acoustic excitations within a structure for various purposes. The acoustic excitation device 14 may be configured to generate preliminary acoustic excitations within a structure, inspection acoustic excitations within a structure, and / or other acoustic excitations within a structure.

[0031] Preliminary acoustic excitations within a structure may represent acoustic excitations generated to test acoustic excitations using various excitation frequencies. Preliminary acoustic excitations can be generated within a structure using multiple (separate, different) excitation frequencies, and measurements of these preliminary acoustic excitations within the structure can be used to select specific excitation frequencies to be used for inspection of the structure. For example, preliminary acoustic excitations can be generated by sweeping a range of excitation frequencies, and measurements of these preliminary acoustic excitations within the structure can be used to identify a subset of tested excitation frequencies for use in a more comprehensive inspection of the structure.

[0032] Inspection acoustic excitations within a structure may represent acoustic excitations generated to inspect the structure. Inspection acoustic excitations can be generated within a structure using a subset of multiple excitation frequencies used for preliminary acoustic excitations. For example, a subset of tested excitation frequencies may be selected based on their effectiveness in generating preliminary acoustic excitations within the structure, and the most effective (e.g., optimal) subset of the tested excitation frequencies can be used to generate inspection acoustic excitations within the structure.

[0033] The acoustic excitation device 14 may be configured to generate acoustic excitations within a structure using a single excitation frequency at a time, or using multiple excitation frequencies at a time. For example, the acoustic excitation device 14 may be configured to generate acoustic excitations within a structure using 10 different excitation frequencies. The acoustic excitation device 14 can generate acoustic excitations using a single excitation frequency at a time (e.g., starting the generation of acoustic excitations within a structure using one excitation frequency, stopping the generation of acoustic excitations within a structure using the same excitation frequency, and starting the generation of acoustic excitations within a structure using different excitation frequencies). The acoustic excitation device 14 can generate acoustic excitations using multiple excitation frequencies simultaneously (e.g., generating acoustic excitations within a structure using all excitation frequencies at once, or generating acoustic excitations within a structure using two or more excitation frequencies at once). In some implementations, the number of excitation frequencies used to generate acoustic excitations within a structure may depend on the maximum output of the acoustic excitation device 14. For example, generating acoustic excitations within a structure using multiple excitation frequencies simultaneously may require sharing the power of the acoustic excitation device 14 across multiple excitation frequencies. Generating acoustic excitations within a structure using multiple excitation frequencies simultaneously may require a trade-off between inspection time and signal level.

[0034] The acoustic measuring device 15 may represent a device for measuring acoustic excitation within a structure. The acoustic measuring device 15 may represent a device for measuring the acoustic response (e.g., velocity response) within a structure. For example, a structure can be acoustically excited by an acoustic excitation device 14 to generate mechanical waves (or more) inside the structure, and the acoustic measuring device 15 can measure one or more characteristics of the mechanical waves (or more) inside the structure, and / or one or more characteristics of the structure that reflect (e.g., indicate, are affected by) the mechanical waves (or more) inside the structure.

[0035] The acoustic measuring device 15 can measure acoustic excitations within a structure by mechanical means (e.g., using one or more transducers), optical means (e.g., using a scanning laser), and / or other methods. For example, acoustic excitations within a structure may be measured through one or more transducers coupled to the structure, a scanning laser Doppler vibrometer, and / or other acoustic measuring devices. For example, the acoustic measuring device 15 can measure the acoustic response within a structure (e.g., the surface velocity response in a full field). The acoustic response may include vibration / wave responses (e.g., the response in a full wave field) within and / or beyond the audible range (ultrasonic response).

[0036] In some implementations, the acoustic measuring device 15 may include a vibrometer. The vibrometer may include one or more vibrometers and / or other devices that measure the amplitude, velocity, and / or frequency of vibrations within a structure. In some implementations, the vibrometer may measure the acoustic response using one or more beams. For example, the vibrometer may include one or more laser Doppler vibrometers that use laser beams to measure the acoustic response in different parts of the structure. The acoustic response may include the amplitude, velocity, and / or frequency of vibrations / waves within the structure. The scanning path may indicate the path that the vibrometer beam(s) track and / or follow along the structure to create the measurements. In some implementations, the vibrometer may use raster scanning to create the measurements.

[0037] The acoustic measuring device 15 may be configured to measure acoustic excitations within a structure. The acoustic measuring device 15 may be configured to measure acoustic excitations within a structure for various purposes. The acoustic measuring device(s) may be configured to measure preliminary acoustic excitations within a structure, inspection acoustic excitations within a structure, and / or acoustic excitations within a structure.

[0038] The acoustic measuring device 15 can be configured to measure preliminary acoustic excitations within a structure and inspection acoustic excitations within a structure in the same or different ways. For example, the acoustic measuring device 15 can create partial measurements of preliminary acoustic excitations within a structure and complete measurements of inspection acoustic excitations within a structure. Partial measurements of acoustic excitations within a structure may be less comprehensive than complete measurements of acoustic excitations within a structure. Partial measurements of acoustic excitations within a structure may include incomplete measurements of acoustic excitations within a structure, while complete measurements of acoustic excitations within a structure may include complete measurements of acoustic excitations within a structure. For example, partial measurements of acoustic excitations within a structure may include measurements at fewer points and / or smaller areas than complete measurements of acoustic excitations within a structure. Partial measurements of acoustic excitations within a structure may include sampling of specific parts of the structure with the aim of determining how much (e.g., how efficiently) different parts of the structure were acoustically excited using different excitation frequencies. A complete measurement of acoustic excitations within a structure may include measurements throughout the structure, aimed at examining the properties of the structure using the measured acoustic excitations (acoustic excitations performed using selected excitation frequencies).

[0039] In some implementations, one or more components of system 10 may be separated from system 10. For example, the acoustic excitation device 14 and / or acoustic measurement device 15 may be separate from system 10 and may be controlled by one or more processors separate from processor 11. The components of system 10 are shown as single components, but this is merely an example and is not intended to be limiting.

[0040] A structure may represent the arrangement and / or organization of one or more objects. Objects may be arranged and / or organized to perform one or more functions to form a structure. A structure may be composed of a specific type of material or a combination of different types of materials. For example, a structure may include a rigid structure made of metal and / or other materials. A structure may have a symmetrical or asymmetrical shape. A structure may include one or more simple geometric shapes, one or more arbitrary complex geometric shapes, and / or other geometric shapes.

[0041] In some implementations, a structure may include hollow structures, support structures, movable structures, and / or other structures. A hollow structure may refer to a structure that contains one or more empty spaces inside. These empty spaces can be used to hold, carry, transport, and / or otherwise interact with one or more objects. For example, hollow structures may include vehicles, containers, pipes, and / or other hollow structures. A support structure may refer to a structure that provides support for one or more objects. For example, support structures may include equipment, platforms, frames, cranes, beams, and / or other support structures. A movable structure may refer to a structure that moves to perform its function. For example, movable structures may include turbine blades and / or other movable structures. Non-limiting examples of structures include one or more parts or wholes of offshore floating production facilities (spars, semi-submersible vessels, tension-leg platforms, etc.), ship / barge hulls, offshore mobile drilling units, aircraft, space launch rockets, wind turbine blades, pressure vessels, piping systems, ballast tanks, void tanks, cargo tanks, etc. Other types of structures are also considered.

[0042] A structure may be inspected to determine whether it can perform its function. For example, a structure may be inspected to determine whether it has any defects such as material addition (e.g., material adhesion), material loss (e.g., corrosion, chipping, pitting), material cracking (e.g., surface cracking, out-of-plane cracking), and / or other defects.

[0043] Various properties of a structure (e.g., the arrangement / structure of materials within the structure) can lead to various responses to acoustic excitations (e.g., resulting in different acoustic excitations). For example, certain types of defects within a structure can cause specific types of acoustic responses in corresponding parts of the structure to acoustic excitations. Measurements of acoustic excitations within a structure (e.g., velocity response) can be used to determine the properties of the structure.

[0044] In some implementations, a structure may represent a part of a larger structure. For example, a structure may represent a region of interest within a larger structure. In other words, it is possible to inspect a specific part of a structure rather than the entire structure.

[0045] Steady-state wave field measurements of structures can be used to identify defects within those structures. However, such inspections may not be able to detect defects smaller than the order of the wavelengths used. For example, while wavenumber estimation of guided ultrasound can be used to identify defects across a region, it may not be able to detect defects smaller than the order of the wavelength, such as cracks or small dents. This is because the defects themselves occupy only a portion of the waveform, making it impractical to accurately estimate the waveform.

[0046] Transient wave field measurements of structures can be used to identify such small defects, but these measurements can be time-consuming. Each individual transient wave field measurement may require waiting for the wave to propagate through the structure to the measurement point and then dissipate. Repeating the wave propagation and dissipation cycle at different measurement points can slow down transient wave field measurements. Transient wave field measurements may also require repeated measurements at the same point to reduce noise, further slowing down the measurement.

[0047] This disclosure utilizes steady-state wave field measurements from multiple excitation frequencies to determine the properties of a structure. For example, steady-state wave field measurements from multiple excitation frequencies (e.g., data on the magnitude of combined velocities from multiple excitation frequencies) can be used to generate a structural damage map that may indicate the location and / or type of defects in the structure. A combination of steady-state wave field measurements from different excitation frequencies can be used to generate a damage map.

[0048] Using steady-state wavefield measurements enables rapid inspection of structures (faster than transient wavefield measurements). Using multiple excitation frequencies allows for probing / inspection of structures at various wavelengths, enabling investigation of defects of various sizes. Furthermore, using steady-state wavefield measurements can result in a higher signal-to-noise ratio than transient wavefield measurements because a large amount of energy may be present within the structure for the inspection to be performed.

[0049] By selecting a specific excitation frequency, steady-state wavefield measurements of a structure can be performed. To do this, various excitation frequencies can be tested on the structure to identify the frequencies that are effective in generating a response within the structure. Different frequencies can produce different acoustic responses within the structure. That is, different acoustic excitations may occur in structures with different excitation frequencies. A subset of the tested frequencies (e.g., the frequency that produced the best / most frequent response) can be selected for detailed multi-frequency steady-state wavefield measurements of the structure. Multi-frequency wavefield measurements of structures can take advantage of the differences in responses of defects of different shapes to different excitation frequencies. For example, detailed multi-frequency steady-state wavefield measurements of a structure can be performed using the excitation frequency that produces the most energetic response within the structure. Using multiple excitation frequencies can increase the amount of information present in the damage map and may enable the determination (e.g., identification, classification, quantification) of defects that would not be displayed using general wavenumber estimations for steady-state wavefield measurements.

[0050] Referring back to Figure 1, the electronic storage device 13 comprises an electronic storage medium for electronically storing information. The electronic storage device 13 can store software algorithms, information determined by the processor 11, information received remotely, and / or other information that enables the system 10 to function properly. For example, the electronic storage device 13 can store information about a structure, preliminary acoustic excitations within the structure, selection of excitation frequencies, inspection acoustic excitations within the structure, characteristics of the structure, and / or other information.

[0051] The processor 11 may be configured to provide information processing functions in the system 10. Therefore, the processor 11 may comprise one or more of the following: a digital processor, an analog processor, a digital circuit designed to process information, a central processing unit, a graphics processing unit, a microcontroller, an analog circuit designed to process information, a state machine, and / or other mechanisms for electronically processing information. The processor 11 may be configured to execute one or more machine-readable instructions 100 to facilitate inspection of a structure. The machine-readable instructions 100 may include one or more computer program components. The machine-readable instructions 100 may include one or more of the following: a preliminary excitation component 102, a preliminary measurement component 104, an excitation frequency selection component 106, a test excitation component 108, a test measurement component 110, a characteristic component 112, and / or other computer program components.

[0052] The preliminary excitation component 102 may be configured to generate preliminary acoustic excitations within the structure. Preliminary acoustic excitations may be generated within the structure using acoustic excitation device 14 and / or other acoustic excitation devices. Preliminary acoustic excitations may be generated within the structure using multiple excitation frequencies. Generating preliminary acoustic excitations within the structure allows testing the structure's response to various excitation frequencies. Preliminary acoustic excitations may be generated within the structure using a single excitation frequency at a time, or using multiple excitation frequencies at a time. Preliminary acoustic excitations within the structure may include preliminary steady-state acoustic excitations within the structure. That is, steady-state acoustic excitations may be generated within the structure to test the structure's steady-state response to various excitation frequencies. The excitation frequencies may include one or more ultrasonic frequencies and / or one or more non-ultrasonic frequencies.

[0053] Multiple excitation frequencies used to generate preliminary acoustic excitations within a structure can be selected manually and / or automatically. For example, a particular excitation frequency may be manually selected by one or more users for use when generating preliminary acoustic excitations within a structure. Alternatively, a particular excitation frequency may be automatically selected by the preliminary excitation component 102 based on the default, the type of structure being inspected (e.g., the geometric shape of the structure, the materials that make up the structure, etc.), the type of characteristic being judged (e.g., the type of defect being judged), and / or other information.

[0054] The selection of a specific excitation frequency used to generate preliminary acoustic excitations within a structure can include the selection of a specific excitation frequency and / or a range of excitation frequencies to be used, along with the frequency increment(s) used. For example, a user can specify a specific value for the excitation frequency used to generate preliminary acoustic excitations within a structure. As another example, a user can specify a range of excitation frequencies to be swept (e.g., from 30 kHz to 120 kHz) along with the increment (e.g., 50 Hz increments / decrements) by which the excitation frequency is changed. In some implementations, the range of excitation frequencies tested and the increment by which the excitation frequency is changed may depend on the type of structure being inspected. It is also intended that other excitation frequencies be selected to generate preliminary acoustic excitations within a structure.

[0055] The preliminary measurement component 104 may be configured to acquire measurements of preliminary acoustic excitations within the structure. Acquiring measurements of preliminary acoustic excitations within the structure may include one or more of accessing, acquiring, analyzing, determining, inspecting, identifying, generating, loading, locating, creating, opening, receiving, searching, overviewing, selecting, saving, obtaining, and / or otherwise acquiring the measurements of preliminary acoustic excitations within the structure. Measurements of preliminary acoustic excitations within the structure can be acquired using acoustic measuring device 15 and / or other acoustic measuring devices(s). Measurements of preliminary acoustic excitations within the structure can be acquired from acoustic measuring device 15, other acoustic measuring devices(s), and / or other locations. For example, the acoustic measurement device 15 can generate information that characterizes, defines, identifies, and / or reflects preliminary acoustic excitations measured within the structure, and this information can be obtained directly from and / or indirectly from the acoustic measurement device 15 (e.g., from the electronic storage device of the acoustic measurement device 15). In some implementations, the measurements of preliminary acoustic excitations within the structure may include measurements of the velocity response within the structure. The preliminary measurement component 104 can obtain measurements of the velocity response within the structure due to preliminary acoustic excitations. In some implementations, the measurements of the velocity response within the structure may be obtained as a raw wavefield image, the size of which reflects the type and / or amount of the velocity response. Other measurements of preliminary acoustic excitations within the structure are also intended.

[0056] In some implementations, measurements of preliminary acoustic excitations within a structure may include partial measurements of preliminary acoustic excitations within the structure. Partial measurements of preliminary acoustic excitations within a structure may include measurements that are less comprehensive than complete measurements. Partial measurements of preliminary acoustic excitations within a structure may include incomplete measurements of preliminary acoustic excitations within a structure. Partial measurements of preliminary acoustic excitations within a structure may include measurements at fewer points and / or in smaller areas of the structure than complete measurements of acoustic excitations within a structure. Partial measurements of preliminary acoustic excitations within a structure may include sampling of specific parts of the structure, aimed at determining how much (e.g., how efficiently) different parts of the structure were acoustically excited using different excitation frequencies.

[0057] In some implementations, the number and / or location of measurements may be determined manually and / or automatically. For example, the number and / or location of measurements may be manually selected by one or more users. Alternatively, the number and / or location of measurements may be automatically selected by a preliminary measurement component 104 based on a default, the type of structure being inspected (e.g., the geometric shape of the structure, the materials that make up the structure, etc.), the type of characteristic being assessed (e.g., the type of defect being assessed), and / or other information.

[0058] In some implementations, the number and / or location of measurements may be determined randomly. In some implementations, the number and / or location of measurements may be determined using one or more scan lines (e.g., a vertical scan line, a horizontal scan line, a diagonal scan line). In some implementations, the direction in which the structure is scanned may be selected to increase the measurement speed.

[0059] The excitation frequency selection component 106 may be configured to select a subset of multiple excitation frequencies. Selecting a subset of multiple excitation frequencies may include checking, selecting, determining, establishing, finding, identifying, acquiring, setting, and / or otherwise choosing a subset of multiple excitation frequencies. A subset of multiple excitation frequencies (used for preliminary acoustic excitation) may contain fewer excitation frequencies than all of them. A subset of multiple excitation frequencies can be selected and used for inspecting a structure. The excitation frequency selection component 106 can select some of the excitation frequencies used to generate preliminary acoustic excitations within the structure. The excitation frequencies can be selected for use when generating inspection acoustic excitations within the structure.

[0060] A subset of multiple excitation frequencies may be selected for use in inspecting a structure based on measurements of preliminary acoustic excitations within the structure and / or other information. Measurements of preliminary acoustic excitations within the structure may be used to determine which of the multiple excitation frequencies used to generate the preliminary acoustic excitations of the structure should be used to generate inspection acoustic excitations within the structure. Various excitation frequencies may result in the occurrence of different types and / or amounts of acoustic excitations within the structure. That is, the type and / or amount of acoustic response within the structure may depend on the excitation frequency used to perform the acoustic excitation. Measurements of preliminary acoustic excitations within the structure can be used to identify the structure's responsiveness to different excitation frequencies, and the structure's responsiveness to different excitation frequencies can be used to select an excitation frequency. For example, measurements of preliminary acoustic excitations within the structure can be used to determine the excitation frequency to which the structure responds most (e.g., ranking excitation frequencies by type and / or amount of acoustic excitations within the structure), and the excitation frequency selection component 106 can select the excitation frequency that produces the most response within the structure. For example, the excitation frequency selection component 106 can select 10 excitation frequencies that produce the highest response within the structure. The selection of other numbers of excitation frequencies is also intended.

[0061] In some implementations, the number of excitation frequencies to be selected can be determined manually and / or automatically. For example, the number of excitation frequencies to be selected can be manually selected by one or more users. As another example, the number of excitation frequencies to be selected can be automatically selected by the excitation frequency selection component 106 based on the default, the type of structure being inspected (e.g., the geometric shape of the structure, the materials that make up the structure, etc.), the type of characteristic being judged (e.g., the type of defect being judged), and / or other information. The number of excitation frequencies to be selected can be related to a trade-off between the accuracy / precision of the inspection and the length of time it takes to perform the inspection. A larger number of frequencies to be selected may result in higher accuracy / precision at the cost of a longer inspection time, while a smaller number of frequencies to be selected may result in faster inspection but lower accuracy / precision.

[0062] In some implementations, selecting a subset of excitation frequencies used to inspect a structure based on preliminary acoustic excitation measurements within the structure may involve selecting a subset of excitation frequencies based on a measure of signal quality of the preliminary acoustic excitation measurements within the structure. The measure of signal quality of the preliminary acoustic excitation measurements within the structure may indicate a measure of the quality of information conveyed by the measurements. For example, the measure of signal quality of the preliminary acoustic excitation measurements within the structure may be determined based on summary statistics (e.g., mean and / or standard deviation) of the velocity response within the structure. For example, preliminary acoustic excitation measurements within a structure may include measurements of vibration velocity at various locations within the structure. The magnitude of the vibration velocity at a given location can provide a measure of energy at that location. The mean and / or standard deviation of vibration velocities measured from preliminary acoustic excitations within the structure can be used to determine the excitation frequency that produced the most response within the structure, and the excitation frequencies that produced the most response within the structure (e.g., the top 10 excitation frequencies) can be selected. The use of other quality measures / summary statistics is intended.

[0063] The inspection excitation component 108 may be configured to generate inspection acoustic excitations within the structure. Inspection acoustic excitations may be generated within the structure using acoustic excitation device 14 and / or other acoustic excitation devices. Inspection acoustic excitations may be generated within the structure using a subset of multiple excitation frequencies. That is, inspection acoustic excitations may be generated within the structure using a portion of the excitation frequencies used to generate preliminary acoustic excitations within the structure. Inspection acoustic excitations may be generated within the structure using an excitation frequency selected by the excitation frequency selection component 106 (e.g., the optimal excitation frequency). Inspection acoustic excitations may be generated within the structure to perform inspection of the structure.

[0064] Inspection acoustic excitations can be generated within a structure using a single excitation frequency at a time, or using multiple excitation frequencies at a time. In-structure inspection acoustic excitations can include steady-state inspection acoustic excitations within the structure. That is, steady-state acoustic excitations can be generated within a structure, and the structure can be inspected using the structure's steady-state response to a selected excitation frequency. The excitation frequencies may include one or more ultrasonic frequencies and / or one or more non-ultrasonic frequencies. For example, an acoustic excitation device(s) can be used to generate steady-state multi-tone ultrasonic excitations of a structure, and the ultrasonic responses of various parts of the structure can be measured and used to determine the characteristics of the structure in the corresponding parts. Using steady-state multi-tone ultrasonic excitations can enable ultrasonic response measurements to be performed quickly (e.g., scanning an area of ​​more than one square meter in a few seconds) from long distances (e.g., tens of meters away) without the need for repetition. Other inspection acoustic excitations of structures are also being considered.

[0065] The inspection and measurement component 110 may be configured to acquire measurements of inspection acoustic excitations in a structure. Acquiring measurements of inspection acoustic excitations within a structure may include one or more of accessing, acquiring, analyzing, determining, inspecting, identifying, generating, loading, locating, creating, opening, receiving, searching, reviewing, selecting, saving, obtaining, and / or otherwise acquiring preliminary acoustic excitation measurements within the structure. Measurements of inspection acoustic excitations within a structure can be acquired using acoustic measuring device 15 and / or other acoustic measuring devices. Measurements of inspection acoustic excitations within a structure can be acquired from acoustic measuring device 15, other acoustic measuring devices, and / or other locations.

[0066] For example, the acoustic measurement device 15 can generate information that characterizes, defines, identifies, and / or reflects the inspection acoustic excitations measured within the structure, and this information can be obtained directly from and / or indirectly from the acoustic measurement device 15 (e.g., from the electronic storage device of the acoustic measurement device 15). In some implementations, the measurements of inspection acoustic excitations within the structure may include measurements of the velocity response within the structure. The inspection measurement component 110 can obtain measurements of the velocity response within the structure due to the inspection acoustic excitations. In some implementations, the measurements of the velocity response within the structure may be obtained as a raw wavefield image, the size of which reflects the type and / or amount of the velocity response. Other measurements of other inspection acoustic excitations in the structure are also intended.

[0067] In some implementations, measurements of inspection acoustic excitations within a structure may include complete measurements of inspection acoustic excitations within the structure. Complete measurements of inspection acoustic excitations within a structure may include more comprehensive measurements than partial measurements. Complete measurements of inspection acoustic excitations within a structure may include measurements at a greater number of points and / or a larger area of ​​the structure than partial measurements of acoustic excitations within the structure. Complete measurements of inspection acoustic excitations within a structure may include sampling of different parts of the structure with the aim of determining how much (e.g., how efficiently) different parts of the structure were acoustically excited using selected excitation frequencies. For example, instead of examining acoustic excitations at a selected number of points, acoustic excitations can be measured throughout the entire structure to generate a complete wavefield measurement that shows the acoustic response of the entire structure / area of ​​interest. Whole wavefield measurements can be used to identify (e.g., visualize) defects within the structure / area of ​​interest.

[0068] The characteristic component 112 can be configured to determine one or more characteristics of a structure. The characteristics of a structure may indicate the physical attributes, quality, and / or properties of the structure. For example, the characteristics of a structure may indicate one or more defects within the structure, the thickness of the structure, the arrangement of materials within the structure, and / or the types of materials that make up the structure. Defects in a structure may include material addition (e.g., material adhesion), material loss (e.g., corrosion, chipping), material cracking (e.g., surface cracking, out-of-plane cracking), and / or other defects. Other types of defects and characteristics of a structure are also considered.

[0069] Determining the characteristics of a structure is based on the characteristics Special This may include determining, quantifying characteristics, and / or making other determinations about the characteristics of the structure. For example, characteristic component 112 may determine the thickness of various parts of the structure, determine the presence and / or absence of one or more defects in the structure, identify the type of defect in the structure, quantify the defect in the structure (e.g., give a specified numerical value), and / or make other determinations about the characteristics of the structure.

[0070] The properties(s) of a structure can be determined by the characteristic component 112 based on measured values ​​of inspection acoustic excitations within the structure and / or other information. The properties(s) of a structure can be determined using the acoustic response of the structure to an excitation frequency (selected by the excitation frequency selection component 106). The amount and / or type of inspection acoustic excitations measured within the structure can be used to determine the properties(s) of the structure. For example, the characteristic component 112 can use the amount and / or type of inspection acoustic excitations in a particular part of the structure to determine the properties(s) of that particular part of the structure. In some implementations, geometric shapes (e.g., excitation shape, excitation focus, excitation width) can be used to determine geometric information (e.g., defect size / shape) related to the properties(s) of the structure.

[0071] For example, the amplitude of a structure's velocity response may indicate the type of defect in the structure (e.g., material addition, material loss, material crack) and / or size (e.g., width, depth). The amplitude profile of the velocity response through the structure can be used to determine the location, shape, and / or size of defects within the structure. Using the velocity response within a structure to determine defects within it may enable the identification and / or quantification of defects hidden from view (e.g., defects below the surface of the structure, covered defects).

[0072] In some implementations, determining the properties of a structure based on measurements of inspection acoustic excitations within the structure may include (1) generating one or more damage maps of the structure based on measurements of inspection acoustic excitations within the structure, and (2) determining the properties of the structure based on the damage maps and / or other information. In some implementations, the damage maps may be displayed within one or more graphical user interfaces. In some implementations, the damage maps may be displayed on one or more displays.

[0073] Damage maps can provide images that visually represent defects in a structure. Damage maps can also provide images that visually represent various characteristics of a structure. For example, damage maps can visually represent various acoustic responses within a structure using various pixel values ​​(e.g., different colors, different intensities).

[0074] In some implementations, damage maps may be generated based on the filtering of measured and / or other information of inspection acoustic excitations within a structure. For example, measured inspection acoustic excitations within a structure can be obtained as a heatmap representing various acoustic responses (e.g., velocity responses) using various pixel characteristics, and damage maps can be generated by filtering the heatmap. In some implementations, filtering can reduce the number of excitation frequencies that need to be used to create an accurate damage map. Filtering may increase the signal-to-noise ratio in the measured inspection acoustic excitations within the structure.

[0075] For example, measurements of inspection acoustic excitations within a structure with respect to excitation frequency may include time-series data, which can be divided into segments corresponding to pixels in the measured grid. The segments may be scattered at complex exponents of the excitation frequency, resulting in a single complex-valued velocity response (amplitude and phase) for each pixel.

[0076] One or more filters can be used to improve the information contained in a heatmap. For example, a bandpass filter can be used to preserve information near the primary spatial frequency while reducing other information as noise. For instance, a bandpass filter can cut out frequencies that are too high or too low while preserving the primary vibration of a structure (along with the surrounding frequencies). Filters can be used to smooth the heatmap and generate a damage map, resulting in a more visible heatmap feature within the damage map. Filters can remove the dominant frequency component from a measurement, making other components of the measurement more visible. In some implementations, the dominant frequency component of a measurement can be determined by converting the heatmap to the wavenumber domain and identifying the maximum value in the wavenumber domain.

[0077] In some implementations, the bandpass filter may be set slightly higher than the dominant structural modes. Such a bandpass filter can enable the detection of small defects that increase the wavenumber (a shift in energy from the dominant modes). Defects in a structure can be found in a damage map by looking for a set of energies that are not the dominant frequency / wavenumber in the defect-free areas. In some cases, the damage map can identify changes in wavenumber without performing wavenumber estimation.

[0078] For example, Figure 3 shows an exemplary processing of a damage map. In Figure 3, the raw data 310 may show measured values ​​of inspection acoustic excitations within a structure using a heatmap. The color / intensity of the heatmap may reflect the amplitude of the velocity response at various locations within the structure. The 2D FFT of the raw data 320 shows the raw data 310 converted to the wavenumber domain. As shown in the 2D FFT of the raw data 320, the circles represent the first mode in which the structure is vibrating. The raw data 320 can be filtered to generate filtered data 330. The filtered data 330 can be used as a damage map of the structure. Certain features of the structure that are not visible in the raw data 310 (e.g., ripple features) are visible in the filtered data 330.

[0079] In some implementations, background signals generated by the excitation mechanism can be removed. In Figure 3, background signals can be removed from the filtered data 330 to generate background-removed data 340. For example, noise may be introduced into the acoustic excitation by the excitation mechanism, and this can be removed. For example, transducers mounted at specific locations within a structure can cause non-uniform acoustic excitation within the structure (e.g., the energy of the acoustic response increases towards the location where the transducer is mounted). In other words, energy can be introduced non-uniformly within the structure. Background removal may include removing distortion of the acoustic excitation caused by the non-uniformly introduced energy. In some implementations, background signals in the data can be identified as the highest value pixels that are less than a certain percentage (e.g., 5%). A plane can be fitted to the background pixels, for example, by using a linear least squares method, and the entire intensity image can be divided into the fitted plane.

[0080] In some implementations, data can be smoothed. For example, in Figure 3, background-removed data 340 can be smoothed to generate smoothed data 350. Smoothing can remove artifacts from the data. For example, filtering the data can introduce ripples into the data (shown in filtered data 330 and background-removed data 340). One or more smoothing kernels can be used to remove ripples from the data, which may make feature identification easier.

[0081] In some implementations, data may be analyzed and / or presented using a logarithmic scale. A logarithmic scale can make the characteristics of the data clearer. For example, in Figure 3, the smoothed data 350 can be represented as logarithmic scale data 360. Defects within the structure (locations with high response) may be easier to identify using logarithmic scale data 360 than using smoothed data 350.

[0082] A composite damage map can be generated by combining damage maps from different excitation frequencies. For example, a composite damage map can be generated by adding the values ​​of damage maps from different excitation frequencies. In some implementations, the values ​​of damage maps from different excitation frequencies may be weighted equally (a response from one excitation frequency is given the same weight as a response from another). In some implementations, the values ​​of damage maps from different excitation frequencies may be weighted differently (for example, a response from one excitation frequency is weighted differently than a response from another). A composite damage map can provide a more comprehensive view of structural defects than individual damage maps.

[0083] Figure 4 shows exemplary damage maps 410, 420, 430, and 440 generated using a variety of frequencies. Damage map 410 shows a logarithmic view of a damage map generated using a single excitation frequency. Damage map 420 shows a logarithmic view of a damage map generated by combining damage maps from two excitation frequencies. Damage map 430 shows a logarithmic view of a damage map generated by combining damage maps from 10 excitation frequencies. Damage map 440 shows a logarithmic view of a damage map generated by combining damage maps from 400 excitation frequencies. As shown in Figure 4, increasing the number of excitation frequencies used can improve the accuracy / precision of the damage map. However, increasing the number of excitation frequencies used may increase the length of time required to perform the inspection.

[0084] Figure 5 shows an illustrative identification of defects in a structure. The structure in Figure 5 may include a steel plate 510, a steel column 520, and a steel plate reinforcement 530. The structure may include the following defects: pitting 540, corrosion 550, and cracks 560. A transducer 500 may be attached to the steel column 520 to generate acoustic excitations in the structure. Different excitation frequencies can be tested on the structure by generating and measuring acoustic excitations within the structure using different frequencies. Using the best-performing (e.g., optimal) excitation frequency obtained from the tests, the structure can be excited using steady-state excitations, and the acoustic excitations of the structure can be measured using these excitation frequencies (e.g., using a laser Doppler vibrometer). The measurements can be used to identify defects in the structure. For example, the measurements can be used to identify the location, shape, size, and / or type of the following defects: pitting 540, corrosion 550, and cracks 560.

[0085] Figure 6 illustrates the exemplary identification of defects in a structure. The structure in Figure 6 may include a steel pipe section 610. The structure may include the following defects: pitting 640, corrosion 650, and cracks 660. A transducer 600 may be attached to the steel pipe section 610 to generate acoustic excitations in the structure. Different excitation frequencies can be tested on the structure by generating and measuring acoustic excitations within the structure using different frequencies. Using the best-performing (e.g., optimal) excitation frequency obtained from the tests, the structure can be excited using steady-state excitations, and the acoustic excitations of the structure can be measured using these excitation frequencies (e.g., using a laser Doppler vibrometer). The measurements can be used to identify defects within the structure. For example, the measurements can be used to identify the location, shape, size, and / or type of the following defects: pitting 640, corrosion 650, and cracks 660. Other types of structural inspection and other types of defects are intended.

[0086] Implementations of this disclosure can be in the form of hardware, firmware, software, or any suitable combination thereof. The embodiment of this disclosure shown in Figure 1 may be implemented as instructions stored on a machine-readable medium, which can be read and executed by one or more processors. The machine-readable medium may include any mechanism for storing or transmitting information in a format readable by a machine (e.g., a computing device). For example, tangible (non-temporary) machine-readable storage media may include read-only memory, random-access memory, magnetic disk storage media, optical storage media, flash memory devices, etc., and machine-readable transmission media may include the form of propagated signals, such as carrier waves, infrared signals, digital signals, etc. Firmware, software, routines, or instructions may be described herein in terms of specific exemplary embodiments and implementations of this disclosure and the execution of specific actions.

[0087] In some implementations, some or all of the functions attributed to System 10 in Figure 1 in this specification may be provided by external resources not included in System 10. External resources may include hosts / sources of information, computing, and / or processing, and / or other providers of information, computing, and / or processing outside of System 10.

[0088] In Figure 1, the processor 11, the electronic memory device 13, the acoustic excitation device 14, and the acoustic measurement device 15 are shown connected to the interface 12, but any communication medium can be used to facilitate direct and / or indirect interaction between any of the components of the system 10. One or more components of the system 10 can communicate with each other via wired communication, wireless communication, or both. For example, one or more components of the system 10 can communicate with each other via a network. For example, the processor 11 can communicate wirelessly with the electronic memory device 13. In non-limiting examples, wireless communication may include one or more of the following: wireless communication, Bluetooth® communication, Wi-Fi communication, cellular communication, infrared communication, or other wireless communication. Other types of communication are contemplated in this disclosure.

[0089] In Figure 1, the processor 11 is shown as a single entity, but this is for illustrative purposes only. In some implementations, the processor 11 may comprise multiple processing units. These processing units may be physically located within the same device, or they may represent the processing functions of multiple devices in which the processor 11 works in conjunction. The processor 11 may be separate from and / or part of one or more components of the system 10. The processor 11 may be configured to execute one or more components by software, hardware, firmware, any combination of software, hardware, and / or firmware, and / or other mechanisms for configuring the processing capabilities of the processor 11.

[0090] Although the computer program components are shown in Figure 1 as being located in the same place within a single processing unit, it should be understood that in an implementation where the processor 11 has multiple processing units, one or more computer program components may be located separately from other computer program components. While computer program components are described as performing or being configured to perform an action, they may include instructions that can program the processor 11 and / or system 10 to perform an action.

[0091] Computer program components are described herein as being implemented via the processor 11 through machine-readable instructions 100, but this is for the sake of ease of reference only and is not intended to limit them. In some implementations, one or more functions of the computer program components described herein may be implemented via hardware (e.g., a dedicated chip, a field-programmable gate array) rather than software. One or more functions of the computer program components described herein may be implemented in software, in hardware, or in both software and hardware.

[0092] The descriptions of the functions provided by the various computer program components described herein are illustrative and not intended to limit any computer program component, as any of them may provide more or less functionality than that described. For example, one or more computer program components may be removed and some or all of their functions may be provided by other computer program components. As another example, processor 11 may be configured to execute one or more additional computer program components that can perform some or all of the functions resulting from one or more computer program components described herein.

[0093] The electronic storage medium of the electronic storage device 13 may be provided integrally with (i.e., substantially inremovably) one or more components of the system 10, and / or as removable storage that can be connected to one or more components of the system 10, for example, via a port (e.g., a USB port, a Firewire port, etc.) or a drive (e.g., a disk drive, etc.). The electronic storage device 13 may include one or more of the following: optically readable storage media (e.g., optical discs, etc.), magnetically readable storage media (e.g., magnetic tape, magnetic hard drives, floppy drives, etc.), charge-based storage media (e.g., EPROM, EEPROM, RAM, etc.), solid-state storage media (e.g., flash drives, etc.), and / or other electronically readable storage media. The electronic storage device 13 may be a separate component within the system 10, or it may be provided integrally with one or more other components of the system 10 (e.g., a processor 11). In Figure 1, the electronic storage device 13 is shown as a single entity, but this is for illustrative purposes only. In some implementations, the electronic storage device 13 may comprise multiple storage units. These storage units may be physically located within the same device, or the electronic storage device 13 may represent the storage functions of multiple devices working together.

[0094] Figure 2 illustrates method 200 for inspecting a structure. The actions of method 200 described below are illustrative. In some implementations, method 200 may be achieved using one or more additional actions not described and / or without one or more of the actions described. In some implementations, two or more actions may occur substantially simultaneously.

[0095] In some implementations, one or more operations of Method 200 may be implemented in one or more processing units (e.g., digital processors, analog processors, digital circuits designed to process information, central processing units, graphics processing units, microcontrollers, analog circuits designed to process information, state machines, and / or other mechanisms for electronically processing information). One or more processing units may include one or more devices that perform some or all of the operations of Method 200 in response to instructions electronically stored in one or more electronic storage media. One or more processing units may include one or more devices that are comprised through hardware, firmware, and / or software specifically designed to perform one or more of the operations of Method 200.

[0096] Referring to Figure 2 and Method 200, in Operation 202, preliminary acoustic excitations can be generated within the structure using multiple excitation frequencies. In some implementations, Operation 202 may be performed by the same or similar components as the acoustic excitation device 14 and / or preliminary excitation component 102 (shown in Figure 1 and described herein).

[0097] In operation 204, measurements of preliminary acoustic excitations within the structure can be obtained. In some implementations, operation 204 may be performed by the same or similar components as the acoustic measurement device 15 and / or preliminary measurement component 104 (shown in Figure 1 and described herein).

[0098] In operation 206, a subset of multiple excitation frequencies may be selected for use in inspecting the structure based on preliminary acoustic excitation measurements and / or other information within the structure. In some implementations, operation 206 may be performed by the same or similar components as the excitation frequency selection component 106 (shown in Figure 1 and described herein).

[0099] In operation 208, the test acoustic excitation may be generated within the structure using a subset of multiple excitation frequencies. In some implementations, operation 208 may be performed by the same or similar components as the acoustic excitation device 14 and / or the preliminary excitation component 108 (shown in Figure 1 and described herein).

[0100] In operation 210, measurements of inspection acoustic excitations within the structure can be obtained. In some implementations, operation 210 may be performed by the same or similar components as the acoustic measurement device 15 and / or inspection measurement component 110 (shown in Figure 1 and described herein).

[0101] In operation 212, one or more characteristics of the structure may be determined based on measured values ​​of test acoustic excitations within the structure and / or other information. In some implementations, operation 212 may be performed by the same or similar components as the excitation frequency selection component 112 (shown in Figure 1 and described herein).

[0102] The systems and / or methods described herein have been described in detail for illustrative purposes based on what is considered to be the most practical and preferred implementations currently available. However, such details are for illustrative purposes only, and it should be understood that this disclosure is not limited to the disclosed implementations, but rather intended to cover modifications and equivalent configurations within the spirit and scope of the appended claims. For example, it should be understood that, where possible, this disclosure is intended to allow the combination of one or more features of any implementation with one or more features of any other implementation.

Claims

1. A method for inspecting structures, Generating preliminary acoustic excitations in the structure using various excitation frequencies, wherein the various excitation frequencies generate preliminary acoustic excitations of various types and / or varying amounts within the structure. Obtaining measurements of various types and / or quantities of preliminary acoustic excitations within the structure from various excitation frequencies, wherein the measurement of preliminary acoustic excitations within the structure is performed at fewer points and / or in a narrower area than the measurement of inspection acoustic excitations within the structure. Selecting a plurality of the various excitation frequencies to be used for inspecting the structure, based on the structure's response to various types and / or varying amounts of preliminary acoustic excitations within the structure at the various excitation frequencies. Using a selection of multiple excitation frequencies, generate the inspection acoustic excitation within the structure. Obtaining measurements of the test acoustic excitation within the structure from a selected excitation frequency, wherein the measurements of the test acoustic excitation within the structure are performed at a greater number of points and / or over a wider area than the measurements of the preliminary acoustic excitation within the structure, and Based on the combination of the measured values ​​of the inspection acoustic excitations within the structure from the selected excitation frequencies, one or more defects in the structure are determined. The method, including the method described above.

2. The method according to claim 1, wherein the preliminary acoustic excitation within the structure includes preliminary steady-state acoustic excitation within the structure, and the inspection acoustic excitation within the structure includes inspection steady-state acoustic excitation within the structure.

3. The method according to claim 1, wherein the measurement of the preliminary acoustic excitation within the structure includes a partial measurement of the preliminary acoustic excitation within the structure, and the measurement of the inspection acoustic excitation within the structure includes a complete measurement of the inspection acoustic excitation within the structure.

4. The method according to claim 1, wherein the measured value of the preliminary acoustic excitation within the structure includes a measured value of the velocity response within the structure.

5. Selecting a plurality of the various excitation frequencies to be used for inspecting the structure, based on the structure's response to various types and / or varying amounts of preliminary acoustic excitations within the structure, The method according to claim 4, comprising selecting a plurality of the various excitation frequencies based on the mean and / or standard deviation of the velocity response of the structure to the various excitation frequencies.

6. Based on the combination of the measured values ​​of the inspection acoustic excitations within the structure from the selected excitation frequencies, one or more defects in the structure can be determined. To generate individual damage maps of the structure based on the measured values ​​of the inspection acoustic excitations within the structure from distinct excitation frequencies among the selected excitation frequencies, wherein each individual damage map visually represents one or more damages within the structure. Generating a composite damage map from the individual damage maps, and The method according to claim 1, comprising determining the defect in the structure based on the composite damage map.

7. The method according to claim 6, wherein the individual damage maps are generated based on filtering of the measured values ​​of the inspection acoustic excitation in the structure.

8. The method according to claim 1, wherein the one or more defects in the structure include the addition of material, the loss of material, or the cracking of material.

9. The method according to claim 1, wherein the structure includes a hollow structure, a support structure, or a movable structure.

10. The aforementioned structure includes steel columns and steel plates having steel plate reinforcement members. The method according to claim 1, wherein the preliminary acoustic excitation and the test acoustic excitation are generated by one or more transducers attached to one or more of the steel columns.

11. The method according to claim 10, wherein the one or more defects of the structure include pitting, corrosion, and / or cracking of the steel plate.

12. The aforementioned structure includes a steel pipe section, The method according to claim 1, wherein the preliminary acoustic excitation and the inspection acoustic excitation are generated by one or more transducers attached to the steel pipe section.

13. The method according to claim 12, wherein the one or more defects of the structure include pitting, corrosion, and / or cracking of the steel pipe section.

14. A system for inspecting structures, the system comprising one or more physical processors, Obtaining measurements of various types and / or quantities of preliminary acoustic excitations within the structure from various excitation frequencies, wherein the preliminary acoustic excitations within the structure are generated using various excitation frequencies, the various excitation frequencies generate various types and / or quantities of preliminary acoustic excitations within the structure, and the measurement of the preliminary acoustic excitations within the structure is performed at fewer points and / or over a narrower area than the measurement of inspection acoustic excitations within the structure. Selecting a plurality of the various excitation frequencies to be used for inspecting the structure, based on the structure's response to various types and / or varying amounts of preliminary acoustic excitations within the structure, wherein the inspection acoustic excitations within the structure are generated using the selected plurality of excitation frequencies. Obtaining measurements of the test acoustic excitations within the structure from selected excitation frequencies, wherein the test acoustic excitations within the structure are generated using a selection of excitation frequencies, and the measurements of the test acoustic excitations within the structure are performed at a greater number of points and / or over a wider area than the measurements of the preliminary acoustic excitations within the structure, and Determining one or more defects in the structure based on a combination of the measured values ​​of the inspection acoustic excitations within the structure from the selected excitation frequency. The system is configured by machine-readable instructions to perform the following.

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