Bryan Zuanetti - Academia.edu (original) (raw)

Papers by Bryan Zuanetti

Metals

Conventional Split Hopkinson Pressure Bars (SHPB) or “Kolsky” bars are often used for determining... more Conventional Split Hopkinson Pressure Bars (SHPB) or “Kolsky” bars are often used for determining the high-rate compressive yield and failure strength of materials. However, for experiments generating very high strain-rates (>103/s) miniaturization of the setup is often required for minimizing the effects of elastic wave dispersion in order to enable the inference of decreasingly short loading events from the data. Miniature aluminum and steel bars are often sufficient for meeting these requirements. However, for high enough strain-rates, miniaturization of steel or aluminum Kolsky bars may require prohibitively small diameter bars and test specimens that could become inappropriate for inferring representative properties of materials with large grain size relative to the test specimen size. The use of a beryllium Kolsky bar setup is expected to enable high rates to be accessible with larger diameter bars/specimen combinations due to the inherent physical properties of beryllium, ...

The 18th International Conference on Experimental Mechanics, 2018

Dynamic Behavior of Materials, Volume 1, 2019

In this paper, we present results from a series of elevated temperature combined pressure-and-she... more In this paper, we present results from a series of elevated temperature combined pressure-and-shear plate impact (PSPI) experiments conducted on polycrystalline commercial purity aluminum (99.999%) and magnesium (99.9%) samples at temperatures ranging from 23 °C to 320 °C. These experiments are designed to study the effect of temperature on flow stress of fcc and hcp metals at ultra-high shear strain rates (greater than 105/s) and high shear strains (approaching 50%). In order to conduct this research, the single-stage gas-gun facility at Case Western Reserve University was modified to include a breech-end sabot heater system and a fully fiber-optics based combined NDI/TDI interferometer. The flow stress of commercial purity aluminum and magnesium, as inferred from the transverse particle velocity record measured at the free surface of a fully elastic Tungsten Carbide (WC) target plate reveal that both sample materials soften when heated to temperatures approximately 50% of their melt temperatures.

In this paper, we present the results from a series of plate impact experiments designed to study... more In this paper, we present the results from a series of plate impact experiments designed to study dynamic response of commercial 99.6% purity tungsten carbide (WC) under simultaneous compression-and-shear stress wave loading. The symmetric oblique plate-impact experiments are conducted using progressively increasing angles of inclination (5°, 10°, and 22°). The longitudinal and transverse components of the measured particle velocity history at the free surface of the target plate in experiments with inclination angles of up to 10° and impact velocities ~100 m/s coincide well with their corresponding elastic particle velocity predictions. However, the normal particle velocity profiles for experiments conducted at an oblique impact angle of 22° are markedly different and exhibit a sudden increase in particle velocity from their plateau levels reminiscent of failure waves observed by other investigators in soda lime glass and silicon carbide (SIC-B). The increase in normal particle vel...

The key to the effective implementation of polymers in structural applications is an understandin... more The key to the effective implementation of polymers in structural applications is an understanding of the mechanical response under a variety of conditions. In this study, an unreinforced poly(etherimide) (PEI) known as Ultem 1000 was characterized under quasi-static and high-strain-rate loading. Standard tension, compression, and torsion experiments were conducted in order to investigate the multi-regime response of this material. The elastic response of the material to multiple loading conditions was correlated using the Ramberg–Osgood model. The effects of thermal and mechanical rejuvenation processes on the mechanical response were investigated; the upper yield strength of the material was reduced, and the strain softening regime responsible for strain localization was largely eliminated. The fracture toughness of the material was evaluated using a Charpy impact test, and the mechanisms of failure were shown to be brittle. The high-strain-rate response of the material to uniaxia...

International Journal of Plasticity, 2021

Abstract Normal and Pressure-shear plate impact (NPI and PSPI) experiments are popular experiment... more Abstract Normal and Pressure-shear plate impact (NPI and PSPI) experiments are popular experimental techniques for studying the mean-field macroscopic behavior of polycrystalline metals under high-rate dynamic loading. However, since both configurations rely upon geometry for subjecting the specimen to high strain rates, these experiments often involve a limited specimen size. Moreover, because of the inherent heterogeneities present within polycrystalline metals, it is difficult to ascertain if the size of the specimen and/or regions where measurements are made are sufficiently large for making representative inferences about the mean-field macroscopic properties from single-point velocity measurements. In the present study, we quantify the expected measurement variability on observable point measurements in NPI and PSPI experiments by carrying out direct numerical simulations (DNS) of statistically representative polycrystalline microstructures subjected to dynamic compression and compression-shear loading. In particular, we consider the role of specific material heterogeneities (e.g. the grain-to-grain difference in size, crystallographic orientation) on dispersion in the normal and transverse particle velocity records and on local fluctuations in key state variables (e.g. velocity, accumulated plastic strain) by incorporating these effects directly into a representative synthetic microstructure geometry and crystalline description of pure polycrystalline aluminum. The form of the present study is a large parametric investigation, consisting of ten ensembles of one hundred simulations. Each of the thousand simulations reflects a randomly realized synthetic microstructure in one of five cases of decreasing average grain size for the two loading configurations. Our analysis of the DNS results demonstrates that for both of these experimental configurations, the grain size directly correlates with the coefficient of variation (CV) in simulated point measurements, showing a convergent decrease in CV to zero (i.e. particle velocity record approaches the mean-field value) with decreasing grain size. Remarkably, the magnitude of variations in the particle velocity record is shown to be largest where the deviatoric stresses are most significant. In the case of NPI, this occurs at the elastic and plastic wavefront, whereas, in the case of PSPI, the magnitude of fluctuations are approximately constant throughout the experimental window time. The reasoning for the scatter in particle velocity due to the heterogeneous microstructure is demonstrated to be dependent on the mechanisms for accommodating deformation and on the interaction of reflection waves generated at sites of heterogeneities occurring at the scale of grains. Lastly, we develop a power-law description for the magnitude of scattering versus characteristic length, which provides a statistical framework for assessing the required number of grains per characteristic specimen dimension for minimizing scatter within these two experimental configurations (NPI, PSPI).

SHOCK COMPRESSION OF CONDENSED MATTER - 2019: Proceedings of the Conference of the American Physical Society Topical Group on Shock Compression of Condensed Matter, 2020

Journal of the Mechanics and Physics of Solids, 2021

Journal of Applied Physics, 2018

International Journal of Impact Engineering, 2019

International Journal of Impact Engineering, 2018

Journal of visualized experiments : JoVE, Aug 7, 2018

A novel approach for conducting normal and/or combined pressure-shear plate impact experiments at... more A novel approach for conducting normal and/or combined pressure-shear plate impact experiments at test temperatures up to 1000 °C is presented. The method enables elevated temperature plate-impact experiments aimed towards probing dynamic behavior of materials under thermomechanical extremes, while mitigating several special experimental challenges faced while performing similar experiments using the conventional plate impact approach. Custom adaptations are made to the breech-end of a single-stage gas-gun at Case Western Reserve University; these adaptations include a precision-machined extension piece made from SAE 4340 steel, which is strategically designed to mate the existing gun-barrel while providing a high tolerance match to the bore and keyway. The extension piece contains a vertical cylindrical heater-well, which houses a heater assembly. A resistive coil heater-head, capable of reaching temperatures of up 1200 °C, is attached to a vertical stem with axial/rotational degre...

Journal of Dynamic Behavior of Materials, 2017

The application of polymers in robust engineering designs is on the rise due to their excellent m... more The application of polymers in robust engineering designs is on the rise due to their excellent mechanical properties such as high fracture toughness, specific strength, durability, as well as, thermal and chemical resistances. Implementation of some advanced polymeric solids is limited due to the lack of available mechanical properties. In order for these materials to endure strenuous engineering designs it is vital to investigate their response in multiple loading rates and conditions. In this thesis, the mechanical response of polyethermide (PEI) is characterized under quasi-static, high strain rate, and multiple impact conditions. Standard tension, torsion, and compression experiments are performed in order to distinguish the multi-regime response of PEI. The effects of physical ageing and rejuvenation on the quasi-static mechanical response are investigated. The strain softening regime resulting from strain localization is eliminated by thermal and mechanical rejuvenation, and ...

Matls. Perf. Charact., 2014

The Review of scientific instruments, 2017

While Photonic Doppler Velocimetry (PDV) has become a common diagnostic tool for the measurement ... more While Photonic Doppler Velocimetry (PDV) has become a common diagnostic tool for the measurement of normal component of particle motion in shock wave experiments, this technique has not yet been modified for the measurement of combined normal and transverse motion, as needed in oblique plate impact experiments. In this paper, we discuss the design and implementation of a compact fiber-optics-based heterodyne combined normal and transverse displacement interferometer. Like the standard PDV, this diagnostic tool is assembled using commercially available telecommunications hardware and uses a 1550 nm wavelength 2 W fiber-coupled laser, an optical focuser, and single mode fibers to transport light to and from the target. Two additional optical probes capture first-order beams diffracted from a reflective grating at the target free-surface and deliver the beams past circulators and a coupler where the signal is combined to form a beat frequency. The combined signal is then digitized and ...