Detecting Localized Plastic Strain by a Scanning Collinear Wave Mixing Method
نویسندگان
چکیده
When the frequencies of a pair of collinear shear and longitudinal waves satisfy the resonant condition, mixing of these two primary waves generates a third, resonant shear wave that propagates in the direction opposite to the propagating direction of the primary shear wave. In this study, experiments were conducted to demonstrate that the acoustic nonlinearity parameter at the location of the mixing zone can be obtained by measuring the resonant shear wave. Since the location of the mixing zone can be controlled by adjusting the trigger time of the transducers that generate the primary waves, this collinear wave mixing technique enables the scanning of a bar sample to measure the distribution of acoustic nonlinearity along the bar. To demonstrate this scanning capability, bar samples with non-uniform acoustic nonlinearity parameters were fabricated by inducing localized plastic deformation at known locations. Scanning collinear wave mixing tests conducted on such bar samples clearly identified the locations of the plastic zone. These results show that collinear wave mixing is a promising method for scanning the test sample to map out the distribution of localized plastic deformation.
منابع مشابه
Measuring acoustic nonlinearity parameter using collinear wave mixing
Related Articles Quantitative evaluation of hidden defects in cast iron components using ultrasound activated lock-in vibrothermography Rev. Sci. Instrum. 83, 094902 (2012) Quantitative trap and long range transportation of micro-particles by using phase controllable acoustic wave J. Appl. Phys. 112, 054908 (2012) Nonlinear nonclassical acoustic method for detecting the location of cracks J. Ap...
متن کاملThe use of non-collinear mixing for nonlinear ultrasonic detection of plasticity and fatigue.
This letter reports on the application of the non-collinear mixing technique to the ultrasonic measurement of material nonlinearity to assess plasticity and fatigue damage. Non-collinear mixing is potentially more attractive for assessing material state than other nonlinear ultrasonic techniques because system nonlinearities can be both independently measured and largely eliminated. Here, measu...
متن کاملNon-collinear wave mixing for non-linear ultrasonic detection of physical ageing in PVC
This work considers the characterization of linear PVC acoustic properties using a linear ultrasonic measurement technique and the non-collinear ultrasonic wave mixing technique for measurement of the physical ageing state in PVC. The immersion pulse-echo measurements were used to evaluate phase velocity dispersion and attenuation of longitudinal waves in PVC test specimens. The suggested nonco...
متن کاملA New Approach for Stress State - Dependent Flow Localization Failure Bounded Through Ductile Damage in Dynamically Loaded Sheets
In this paper, a new approach is proposed for stress state - dependent flow localization in bifurcation failure model bounded through ductile damage in dynamically loaded sheets. Onset of localized necking is considered in phenomenological way for different strain rates to draw the forming limit diagram (FLD). Using a strain metal hardening exponent in the Vertex theory related to the strain ra...
متن کامل