A tool having at least one vibration sensor and at least one standoff is disposed in a contact with a material and the at least one standoff of the tool is pushed into the material. Vibration is excited by the at least one vibration source and at least one coupling frequency of the tool is measured by the at least one vibration sensor. Based on the determined coupling frequency determining a contact stiffness of the at least one standoff and the mechanical properties of the material are determined taking into account mechanical properties of the at least one standoff.

A multimode ultrasonic probe tip and transducer integrated into a micro tool, such as a nano indenter or a nano indenter interfaced with a Scanning Probe Microscope (SPM) is described. The tip component may be utilized to determine mechanical properties or characteristics of a sample, including for example, complex elastic modulus, hardness, friction coefficient, and strain and stress at nanometer scales and high frequencies. The tip component is configured to operate at multi-resonant frequencies providing sub-nanometer vertical resolution. The tip component may be quasi-statistically calibrated and contact mechanics constitutive equations may be utilized to derive mechanical properties of a sample. Contact mechanical impedance and acoustic impedance may also be compared.

A noncontact vibration measurement enables detection of acoustic emissions from fracture events in soft materials experimentally determined to be highly correlated to fracture energies, the latter revealing the toughness of the material.

A system and a method for validating damping material dynamic property are provided. In the method, a measured platform is established by a viscoelastic material firstly, and then obtains a measured frequency response data. Following up, establish a viscoelastic model for a viscoelastic material, and than derived the viscoelastic function based viscoelastic model. Then, the viscoelastic function is substitute into a dynamic load equation; further obtains a simulation storage modulus and a simulation loss modulus. Then, obtain a simulation frequency response data by the simulation elastic modulus and the simulation viscosity coefficient. Next, obtain the integrated frequency response data according to the reference temperature with an algorithm. Finally, calculating out an elastic modulus value and the viscosity coefficient value by the integrated frequency response data.

A material testing machine, including a machine body, a first fixing element, a second fixing element and a detection assembly; the first and the second fixing elements are mounted to the machine body, the first fixing element is configured to mount a first testing element, and the second fixing element is configured to mount a second testing element; in a first state, the first and the second testing elements are in sliding contact; in a second state, the first fixing element drives the first testing element to collide with the second testing element; the detection assembly is configured to detect a target parameter, and in the first state, the target parameter includes a friction force and/or, a friction sound between the first and the second testing elements; and in the second state, the target parameter includes a collision force received by the first or the second testing element.

In a vibration information detection step, a probe is inserted into a food sample, and any one of the displacement, the velocity or the acceleration of a vibration occurring on the probe by the insertion is detected as vibration information (step S1). In a frequency band dividing step, the vibration information is divided by a band pass filter into individual pieces of vibration information in each of a plurality of frequency bands (step S2). In a food texture index calculation step, a food texture index value based on vibrational energy per unit time in each of the frequency bands is calculated using a computer from the vibration information in each of the frequency bands and the center frequency of the corresponding frequency band (step S3).

A tool having at least one vibration sensor and at least one standoff is disposed in a contact with a material and the at least one standoff of the tool is pushed into the material. Vibration is excited by the at least one vibration source and at least one coupling frequency of the tool is measured by the at least one vibration sensor. Based on the determined coupling frequency determining a contact stiffness of the at least one standoff and the mechanical properties of the material are determined taking into account mechanical properties of the at least one standoff.

The present disclosure relates to a method and a system for determining the mechanical state of an agricultural land, wherein sensors, arranged in a tillage element of an agricultural machine, obtain measurements of a vibratory signal which is the product of the tillage operation of the agricultural machine on the land. Communication means send said measurements in data packets to a processor module. The processor module transfers the measurements to the frequency domain and calculates energy measurements in order to finally determine the mechanical state of the agricultural land, based on the analysis of said calculated energies, wherein the mechanical state determined comprises a degree of hardness and a degree of plasticity.

A dual piezoelectric wire sensor system and a method for non-destructive testing of a cylindrical structure utilizes a pair of H-shaped calipers attached to the cylindrical structure at radial positions ninety degrees apart. Each H-shaped caliper includes two arms and a crossbar connected to and perpendicular to the two arms. A caliper connecter is attached to the first ends of each arm. A wire connecter is attached to the second ends of each arm, between which a piezoelectric wire is connected and stretched. An electrical terminal connects one wire connector to a two-port signal subtractor, which receives signals from the two H-shaped calipers and generates a difference signal. A measurement unit, connected to the two-port signal subtractor, receives the difference signal, performs a frequency analysis, identifies a resonant frequency of an ovalling mode and identifies a stiffness value of the cylindrical structure.