2021-04-07 08:00:00
In woven composite material, microscopic damage phenomena including fiber-matrix interface debonding, fiber breakage, and matrix fracture will subsequently result in macroscopic failure behaviors. Conventional detailed micromechanical models for predicting the effective composite material property are limited to microscale due to high computational cost. Continuum…
The integrative model “integrates” various mechanisms at the continuum level which can possibly be developed within the target material subjected to projectile impact. The possible mechanisms that can be developed within the material include evolution of the initial cracks which has been modeled based…
At present, methods for evaluating helmet performance focus primarily on head kinematics as a means of quantifying risk of brain injury. Head kinematics are used as inputs in computational models of injury, as well as a range of impact severity measures, in an effort…
Porous and particulate materials with internal microstructure exhibit complex constitutive mechanical responses, but informing constitutive laws based on microstructural information remains a significant challenge. We demonstrate a surrogate modeling approach to this problem, using both Gaussian processes and neural network regression techniques in combination…
Magnesium alloys are an attractive material system for protection applications owing to their high specific strength and stiffness, but have low failure strains relative to similar strength lightweight metals in this application (e.g. Al, Ti). The plastic anisotropy from the low-symmetry HCP crystal structure…
We have been conducting hypervelocity impact tests and numerical simulations in order to create Japanese design guidelines that protect satellites against a certain degree of impact by micrometeoroids and orbital debris (hereinafter referred to as M/OD). Certain members of JAXA, university researchers, computer analysts,…
In fiber-reinforced composites, cracks initiate around the fibers aligned transversely to the loading direction. The transverse cracks can potentially cause leakage in specific applications or progress to inter-ply delamination and catastrophic failure. Initiated micro-cracks can go undetected since the instantaneous loss in the composites’…
With the development of directed energy weapons (DEWs) such as high energy lasers and high-power microwave (HPM) weapons, there is a growing concern regarding the unknown biological effects that result from directed energy exposure. In this study, we create a multiphysics computational framework to…
Cellular solids such as foam are high performance energy absorbers and are widely used in the field of automobile impact safety. Their microstructure provides the ability to undergo large plastic deformations at near constant plateau stresses, so they can absorb large amounts of kinetic…
Sizing emulsions are key in stabilization of glass fibers for use in the fiber-reinforced composites that continue to enjoy rapid growth in applications. To tailor composites with enhanced performance, it is necessary to understand the chemistries that determine sizing emulsion performance, including the epoxy…
