Abstract: A twin pneumatic hammer is provided. The twin pneumatic hammer includes a first hammer head connected to a first pneumatic cylinder mounted on a first caliper arm, and a second hammer head connected to a second pneumatic cylinder mounted on a second caliper arm. The second hammer head is positioned opposite to the first hammer head. The first and second caliper arms are slidably coupled to a sliding track of a caliper base such that a distance between the first and second caliper arms may be adjusted. A plurality of tubing connects the first and the second pneumatic cylinders to a source of compressed air. An air controller is connected to the source of compressed air and performs a simultaneous impact stroke of the first and second hammer heads by controlling the release of compressed air into the plurality of tubing.

Abstract: A method includes exciting a vibration of a solid material preferably in cylindrical shape, detecting the vibration by a pair of transducers attached at opposing positions on the solid material and preferably orthogonally aligned to the excitation force, adding the pair of sensor signals to mostly cancel bending mode signal components, and processing the added output signal to obtain a frequency spectrum. A method may also include identifying a resonance peak of an extensional mode diametrically symmetric, measuring a characteristic of the resonance peak, comparing the characteristic with a series of measured values for standard samples, and determining a defect status such as decay in a wooden pole solid material.

Abstract: The present disclosure relates to evaluating an ovaling mode in a cylindrical object and determining a quality of the cylindrical object by analysis of the ovaling mode. In an embodiment, the present disclosure relates to a method for determining a structural quality of a cylindrical element, comprising measuring, as a result of a single applied force, surface vibrations of the cylindrical element via four or more surface transducers arranged on the cylindrical element along a circumference of the cylindrical element, the four or more surface transducers being equally spaced along the circumference, processing digital signals corresponding to each of the four or more surface transducers in order to generate a composite digital signal, transforming the composite digital signal to a frequency domain, comparing the transformed composite digital signal to a reference composite digital signal, and determining, based on the comparing, the structural quality of the cylindrical element.

Abstract: A testing apparatus, method and system for determining the ovaling mode in a cylindrical object, which may be excited through the synchronous application of two diametrically opposed identical vibrators to the outer perimeter. At least one vibration sensor transforms the vibrations to electrical voltage signals. Two vibration sensors placed at diametrically opposed locations, each halfway between the vibration inducers, may be used with a summer for adding the in phase response signals. The signal response is then converted into a digital signal and transformed into the frequency domain through a Fourier transform for determining the frequencies of the modes of interest. The resonant frequency of the ovaling mode of the element is identified and compared to that of a reference cylindrical object with comparable cross-sectional size to establish the stiffness and soundness degree of the cylindrical object. A structural integrity report including the strength and stiffness is generated.

Abstract: The present disclosure relates to evaluating an ovaling mode in a cylindrical object and determining a quality of the cylindrical object by analysis of the ovaling mode. In an embodiment, the present disclosure relates to a method for determining a structural quality of a cylindrical element, comprising measuring, as a result of a single applied force, surface vibrations of the cylindrical element via four or more surface transducers arranged on the cylindrical element along a circumference of the cylindrical element, the four or more surface transducers being equally spaced along the circumference, processing digital signals corresponding to each of the four or more surface transducers in order to generate a composite digital signal, transforming the composite digital signal to a frequency domain, comparing the transformed composite digital signal to a reference composite digital signal, and determining, based on the comparing, the structural quality of the cylindrical element.

Abstract: A testing apparatus, method and system for determining the ovaling mode in a cylindrical object, which may be excited through the synchronous application of two diametrically opposed identical vibrators to the outer perimeter. At least one vibration sensor transforms the vibrations to electrical voltage signals. Two vibration sensors placed at diametrically opposed locations, each halfway between the vibration inducers, may be used with a summer for adding the in phase response signals. The signal response is then converted into a digital signal and transformed into the frequency domain through a Fourier transform for determining the frequencies of the modes of interest. The resonant frequency of the ovaling mode of the element is identified and compared to that of a reference cylindrical object with comparable cross-sectional size to establish the stiffness and soundness degree of the cylindrical object. A structural integrity report including the strength and stiffness is generated.

Abstract: A method includes initiating a vibration of the solid material preferably in cylindrical shape, detecting the vibration by a pair of transducers attached opposing positions diametrically symmetric on a surface of the solid material, and aligned at an angle between a line connecting the pair of transducers and a radial direction of the excitation force being orthogonal, processing an electrical output signal generated by adding the pair of sensor signals to obtain a frequency spectrum. A method may also include identifying a resonance peak of an extensional mode diametrically symmetric, measuring a characteristic of the resonance peak, comparing the characteristic with a series of measured values for standard samples, and determining a defect status. A device includes a vibration exciting tool, a pair of transducers configured to be attached to the surface of the solid cylindrical material aligned at opposing positions diametrically symmetric, a voltage adder, and an analyzing unit.