Correlated Solutions recently assisted in an important research project in the College of Engineering and Computing at the University of South Carolina with members of Dr. Austin Downey’s research group who are investigating the degradation parameters of rapidly discharging Lithium-ion batteries in the ARTS lab (Adaptive Real-Time Systems). In some cases – especially in defense and aerospace applications – it is necessary to push battery performance to extreme limits. Dr. Downey’s team, working with support from the NSF and Airforce Research Laboratory are using a NHR 9200 Battery Test System to investigate the material characteristics of an 18650 2500mAh 20A battery as it rapidly discharges.

In this test, the focus is on Current Interrupt Devices (CID). CIDs play a critical role in ensuring safety in high-performance battery applications by interrupting current flow when it exceeds a predetermined safe limit. This prevents battery cells from overheating, which can lead to damage, fire, or even explosion. In high-performance batteries that are designed to deliver large amounts of current very quickly, this protection is essential to prevent catastrophic failure.

This paper describes a series of experiments in which truncated cone geometries were formed using two multistage methods and compared to the same geometry formed using the traditional single stage method. The geometric accuracy and thickness distributions, including 3D thickness distribution plots, of each are examined using digital image correlation (DIC).

The proposed method is based on measurements of nonuniform deformations of the rail under thermal loading, as observed in computer simulations and laboratory investigations. The implementation uses thermal imaging and three-dimensional stereo-digital image correlation technology to acquire full-field deformations.

To measure the inhomogeneous 3D-strain fields present during inflation-extension testing of physiologically submerged micro-aneurysms, a Stereo Digital Image Correlation (StereoDIC) microscopy system is developed that revolves 15° stereo-angle cameras around a centrally-mounted target. Calibration is performed using submerged dot patterns and system accuracy verified using strain and deformation analyses for rigid body motions of speckle-patterned, micro-aneurysmal surrogates. In terms of the Green-Lagrange strain tensor and the 3D displacement fields, the results are stable even after 120 minutes, with maxima in both strain bias and strain standard deviation less than 2E-03 for all components, and micron-level displacement standard deviation.

A reinforced rubber matrix composite is mounted between two grips, and a set of reference images are acquired from a CT scanner at know increments. Each ‘slice’ of data is then analyzed to compute a static volume measurement. After the specimen undergoes a tensile load, images are acquired again by the CT scanner at the same locations.

The VIC-3D Stereo Microscope System The VIC-3D stereomicroscope system enables local analysis within very small elements. One industry that benefits from this small field imaging is microelectronics.

A rubber puck is mounted between two grips, and a set of reference images are acquired from a CT scanner at know increments. Each ‘slice’ of data is then analyzed to compute a static volume measurement. After the puck undergoes a compression load, images are acquired again by the CT scanner at the same locations. Digital Image Correlation algorithms are used to calculate the volumetric change or deformation at each individual voxel, which make up the 3D volume.

Understanding thermo-mechanical behavior of material can be a vital component when designing vehicles and structures that may become exposed to high temperatures. Virginia Tech’s Extreme Environments, Robotics, and Materials (ExtReMe) Laboratory focuses on the impact of extreme environments on materials. This includes research that is focused on understanding the thermo-mechanical behavior of materials both during and following fires. Experimental investigations are performed to understand the evolution of the material due to elevated temperature.

Studying the behavior of metals during a high-speed dynamic compression event has always been challenging due to the complex test set up and fast data capture rates required. Currently, very little literature is available regarding deformation behavior at strain rates of 10 to 500s-1. Utilizing high-speed cameras, the VIC-3D HS system can be used to quantify the surface displacements and strains in three dimensions over the entire field with great precision. Digital image correlation (DIC) has gained widespread popularity over recent years in such high-speed applications due to its high accuracy, flexibility and ease of use.

In this study, for the first time, a novel full-field three dimensional (3D) blister test via stereo-digital image correlation (StereoDIC) was developed to characterize the interfacial interaction between as-grown graphene on nickel (Ni) and copper (Cu) substrates, respectively.