Incremental calculation for large deformation measurement using reliability-guided digital image correlation

In-plane and out-of-plane crushing properties of the honeycomb core were investigated experimentally and with Digital Image Correlation. The out-of-plane direction of the core was found as the strongest direction which absorbed significant amount of energy during deformation. The ribbon direction was found two times stronger as compared to the transverse direction. Local deformation response in in-plane crushing was analyzed with Digital Image Correlation. It was found that the local plastic strain in the core was mainly in the shear band regime. Additionally, the local plastic strain was found higher as compared to the global stress level. The combination of experimental and Digital Image Correlation results worked excellently well in the determination of global and local deformation mechanism of the honeycomb core.

Experimental investigation of in-plane and out-of-plane crushing of aluminum honeycomb

Full-field characterization of mechanical behavior of polyurethane foams

The foam material of interest in this investigation is a rigid closed-cell polyurethane foam PMDI with a nominal density of 20 pcf (320 kg/m{sup 3}). Three separate types of compression experiments were conducted on foam specimens. The heterogeneous deformation of foam specimens and strain concentration at the foam-steel interface were obtained using the 3-dimensional digital image correlation (3D-DIC) technique. These experiments demonstrated that the 3D-DIC technique is able to obtain accurate and full-field large deformation of foam specimens, including strain concentrations. The experiments also showed the effects of loading configurations on deformation and strain concentration in foam specimens. These DIC results provided experimental data to validate the previously developed viscoplastic foam model (VFM). In the first experiment, cubic foam specimens were compressed uniaxially up to 60%. The full-field surface displacement and strain distributions obtained using the 3D-DIC technique provided detailed information about the inhomogeneous deformation over the area of interest during compression. In the second experiment, compression tests were conducted for cubic foam specimens with a steel cylinder inclusion, which imitate the deformation of foam components in a package under crush conditions. The strain concentration at the interface between the steel cylinder and the foam specimen was studied in detail.more » In the third experiment, the foam specimens were loaded by a steel cylinder passing through the center of the specimens rather than from its end surface, which created a loading condition of the foam components similar to a package that has been dropped. To study the effects of confinement, the strain concentration and displacement distribution over the defined sections were compared for cases with and without a confinement fixture.« less

Full-field characterization of mechanical behavior of polyurethane foams.

Huiqing Jin

Papers

Full-field characterization of mechanical behavior of polyurethane foams.

Green solvents-based molecular weight controllable fractionation process for industrial alkali lignin at room temperature.

Separation of surface sediments generated during the pre-hydrolysis via an efficient solvent dissolution and its physicochemical characterization

Validation of a Viscoelastic Model for Foam Encapsulated Component Response Over a Wide Temperature Range.

Modulating the emission spectrum of Ca2La8(SiO4)6O2:Eu(2+,3+) phosphor through Mn2+ ion doping