2023-04-05 08:00:00
A finite strain continuum theory is advanced for static and dynamic simulations of material response under combined mechanical and magnetic fields. The general thermomechanical theory accounts for nonlinear thermoelasticity, plastic flow from slip and twinning, damage mechanics from voids, and phase transformations. Maxwell’s equations…
Deformation-induced microstructural modification is utilized by several high-strain processing methods such as rolling, friction-stir-based processing, welding, or additive manufacturing. Consistent distribution of high density of crystallographic defects allows heterogeneous nucleation sites for nano-scale precipitation of intermetallic phases and often results in high-performing nanostructured alloys….
A homogenized framework for ductile damage accounting for the effect of void growth on the thermomechanical response of single crystals under dynamic loading (CPD-FE) is developed. The current framework extends our prior work (Nguyen et al., 2017) by incorporating the yield function of Han…
Plate impact experiments were performed to probe the dynamic response of Galfenol, specifically the Hugoniot elastic limit (HEL), spall strength, and failure characteristics. Galfenol exhibits low HEL and high spall strength as compared to α-Fe, possibly owing to the large grain size and strong…
The deformation and damage mechanisms in (α+β) titanium alloys lead to plastic strain inhomogeneity at the micro-level, calling for extensive characterization efforts. For example, exhibiting a Burgers orientation relationship (BOR) between the BCC-structured retained β-phase (βr) and the HCP-structured transformed β-phase (βt), the transformed…
Predicting the failure of crystalline materials requires knowledge of the underlying failure mechanisms and their dependence on microstructure. When undergoing high strain rate deformation, ductile metals generally follow a pathway of nucleation, growth, and coalescence of voids followed by failure. In order to adequately…
Existing methods to design metamaterials for dynamic loading involve tuning the crushing behavior so that sufficient energy can be absorbed over extremely short time scales. While this approach is effective for manipulating and dispersing low to moderate amplitude loads, when lattice-based metamaterials are subjected…
The deformation behavior of BCC metal microstructures at high pressures has contributions from dislocation slip, deformation twinning, and phase transformation. The current efforts to investigate plasticity contributions in BCC metals are largely limited to real-time in situ x-ray diffraction (XRD) and single-crystal (sc) systems….
Conventional engineering design for structural materials relies on the implementation of large safety factors and inefficient overdesign. More modern approaches seek to develop metamaterials focusing on the topology. However, emphasis on material selection and metallurgy is needed to enable such optimized topological designs. A…
From Da Vinci to Galileo to modern experimentalists a variety of characterization methods have been introduced for investigating the fracture of materials. However, determining fracture properties of materials at small length scales, with complex shapes, under extreme environmental conditions, is still extremely challenging. This…
