The present disclosure proposes a non-baseline on-line stress monitoring system and monitoring method based on multi-mode Lamb wave data fusion. A Lamb wave dispersion curve is established according to geometric dimensions and material parameters of a measured object, a cut-off frequency of a first-order Lamb wave mode is obtained, an excitation frequency of a Lamb wave signal is determined, and then pure Lamb waves in S0 and A0 modes obtained inside the measured object are obtained; an acoustoelastic equation is established, an elastodynamic equation of the measured object under a prestress condition is solved, and linear relationships between a group velocity and a stress of the Lamb waves in the S0 and A0 modes under the excitation frequency are obtained; data is processed through the on-line monitoring system; a stress gradient in a depth direction is calculated, and finally, a stress state of the measured object is represented. The present disclosure does not require data under a zero stress state as baseline data, does not require designing a wedge block capable of generating a critical refraction longitudinal wave, and combines acoustoelastic effects of Lamb waves in different modes to realize online stress monitoring without the baseline data.

The present disclosure proposes a non-baseline on-line stress monitoring system and monitoring method based on multi-mode Lamb wave data fusion. A Lamb wave dispersion curve is established according to geometric dimensions and material parameters of a measured object, a cut-off frequency of a first-order Lamb wave mode is obtained, an excitation frequency of a Lamb wave signal is determined, and then pure Lamb waves in S0 and A0 modes obtained inside the measured object are obtained; an acoustoelastic equation is established, an elastodynamic equation of the measured object under a prestress condition is solved, and linear relationships between a group velocity and a stress of the Lamb waves in the S0 and A0 modes under the excitation frequency are obtained; data is processed through the on-line monitoring system; a stress gradient in a depth direction is calculated, and finally, a stress state of the measured object is represented. The present disclosure does not require data under a zero stress state as baseline data, does not require designing a wedge block capable of generating a critical refraction longitudinal wave, and combines acoustoelastic effects of Lamb waves in different modes to realize online stress monitoring without the baseline data.

Systems for ultrasonic measurements of an inspection surface is described. An inspection robot with a payload moves in a direction of travel across an inspection surface. The payload has two sensor holders, the first sensor holder to hold a first UT array at a first orientation and the second to hold a second UT array at a second orientation A sensor holder linking component holds the two UT phased arrays in a parallel configuration along their long edges. An arm of the payload may be pivotably connected to both the sensor linking component at one end and a lift connection element on the other end. The lift component has a lift motor to raise the lift connection element. A rastering device moves the payload in a direction of inspection which is distinct from both the direction of travel and the parallel configuration of the two phased UT arrays.

The invention comprises a device and method to estimate the elasticity of soft elastic solids from surface wave measurements. The method is non-destructive, reliable and repeatable. The final device is low-cost and portable. It is based in audio-frequency shear wave propagation in elastic soft solids. Within this frequency range, shear wavelength is centimeter sized. Thus, the experimental data is usually collected in the near-field of the source. Therefore, an inversion algorithm taking into account near-field effects was developed for use with the device. Example applications are shown in beef samples, tissue mimicking materials and in vivo skeletal muscle of healthy volunteers.

The invention comprises a device and method to estimate the elasticity of soft elastic solids from surface wave measurements. The method is non-destructive, reliable and repeatable. The final device is low-cost and portable. It is based in audio-frequency shear wave propagation in elastic soft solids. Within this frequency range, shear wavelength is centimeter sized. Thus, the experimental data is usually collected in the near-field of the source. Therefore, an inversion algorithm taking into account near-field effects was developed for use with the device. Example applications are shown in beef samples, tissue mimicking materials and in vivo skeletal muscle of healthy volunteers.

A rapid ultrasonic dual-wave calibrated detection method includes: numbering a plurality of high strength bolts; searching, in a database in equipment, a calibrated empirical value R.sub.0e of initial ratios R.sub.0 of ultrasonic transverse wave transit time to ultrasonic longitudinal wave transit time for bolts with entirely or partially same specification data, or a calibrated empirical value k.sub.e of a slope k of variation of a bolt tension with a ratio of transverse wave transit time to longitudinal wave transit time; measuring ratios R.sub.i of the ultrasonic transverse wave transit time to the longitudinal wave transit time for the plurality of high strength bolts; acquiring a pretightening axial force value, and using the pretightening axial force value in place of an average value of tensions of the plurality of high strength bolts, calculating calibrated another parameter k.sub.e or R.sub.0e; and calculating axial forces of the high strength bolts.

A rapid ultrasonic dual-wave calibrated detection method includes: numbering a plurality of high strength bolts; searching, in a database in equipment, a calibrated empirical value R.sub.0e of initial ratios R.sub.0 of ultrasonic transverse wave transit time to ultrasonic longitudinal wave transit time for bolts with entirely or partially same specification data, or a calibrated empirical value k.sub.e of a slope k of variation of a bolt tension with a ratio of transverse wave transit time to longitudinal wave transit time; measuring ratios R.sub.i of the ultrasonic transverse wave transit time to the longitudinal wave transit time for the plurality of high strength bolts; acquiring a pretightening axial force value, and using the pretightening axial force value in place of an average value of tensions of the plurality of high strength bolts, calculating calibrated another parameter k.sub.e or R.sub.0e; and calculating axial forces of the high strength bolts.

Methods, systems, and computer-readable storage media for providing high-resolution assessment of the condition of pipes of a fluid distribution down to the individual pipe stick. An acoustic sensor is placed in acoustical communication with a pipe at one end of a target segment. An acoustical wave is generated in the pipe at a first out-of-bracket excitation location while signal data is recorded from the acoustic sensor. Timing information regarding the arrival at the acoustic sensor of reflections of the acoustic wave from pipe joints in the target segment is extracted from the recorded signal data, and a time delay between reflections from consecutive pipe joints is computed. An acoustic propagation velocity in a pipe stick between the consecutive pipe joints is then computed based on the time delay and a length of the pipe stick. A condition of the pipe stick is determined based on the computed acoustic propagation velocity.

Methods, systems, and computer-readable storage media for providing high-resolution assessment of the condition of pipes of a fluid distribution down to the individual pipe stick. An acoustic sensor is placed in acoustical communication with a pipe at one end of a target segment. An acoustical wave is generated in the pipe at a first out-of-bracket excitation location while signal data is recorded from the acoustic sensor. Timing information regarding the arrival at the acoustic sensor of reflections of the acoustic wave from pipe joints in the target segment is extracted from the recorded signal data, and a time delay between reflections from consecutive pipe joints is computed. An acoustic propagation velocity in a pipe stick between the consecutive pipe joints is then computed based on the time delay and a length of the pipe stick. A condition of the pipe stick is determined based on the computed acoustic propagation velocity.

The present invention relates to a method for evaluating the thermal expansion properties of a titania-containing glass body. On the basis of measured values, obtained at a certain temperature, for a physical parameter that changes depending on the titania concentration and a physical parameter that changes depending on the fictive temperature, the thermal expansion coefficient of the titania-containing silica glass body and the slope of the thermal expansion coefficient are calculated using a linear relational expression represented by a plurality of physical properties. The thermal expansion properties of the titania-containing silica glass body are evaluated on the basis of the calculated thermal expansion coefficient and thermal expansion coefficient slope.