Indentation Measurement in Thin Plates under Bending Using 3D Digital Image Correlation

Abstract

In the current paper, a novel experimental methodology to characterize the contact behavior on thin plates under bending is presented. The method is based on the experimental measurement of the indentation observed during contact experiments. Tests were conducted using aluminum thin plates and a steel sphere to evaluate the effect of thickness and bending during contact. For this purpose, a non-contact optical technique, 3D Digital Image Correlation (3D-DIC), has been employed to measure the out-of-plane displacements experienced at the rear face of the specimens (opposite where the contact is occurring). An indirect measurement of the experimental contact law is obtained for different plate thicknesses (2 mm, 3 mm, 4 mm, 5 mm and 6 mm) as the contact load increases. An energy balance performed during contact experiments made it possible to evaluate and quantify the applied energy to generate bending and contact deformation. When the specimen thickness increases from 2 mm to 6 mm, contact deformation reaches higher values from the total applied energy. In addition, it is also possible to evaluate the portion of the elastically recovered energy for contact and bending deformation during the unloading. It has been observed that thicker specimens show a lower elastic energy recovery due to bending and a higher elastic energy recovery due to contact. Results clearly show how the ratio between absorbed and applied energy changes as the specimen thickness increases, highlighting the relevance of the proposed method for the characterization of contact behavior in thin plates.

Analysis of fracture mechanisms of ultrathin glass for flexible cover window under pen drop conditions

“…This result implies that the maximum displacement increased to a certain extent and then saturated under the influence of the soft film structures attached below the UTG. However, when the fracture displacement is discussed in relationship with Hertzian ring crack diameter, the thickness effect should also be considered the applied energy, elastic energy, and permanent damage decrease with thickness as reported by Almazán-Lázaro et al 39 We believe, thus, further study is required for UTG to clearly understand the effect of thickness on the fracture mechanism of UTG. Deformation and fracture by the PDT were difficult to quantify or analyze in the real environment, even using the state-of-the-art high-speed cameras.…”

Effectiveness of Selected Strain and Displacement Measurement Techniques in Civil Engineering

“…It is the effect of load acting on the beam on displacement in the α-α cross-section. The results discussed in Section 3.2 demonstrate that the accuracy of all measurement techniques was good enough and that they can be used to measure displacement in construction work [26][27][28][29][30].…”