dmHUB invites you to attend the Global Composites Experts Webinar Series.
Title: Control of Reaction Fronts for Rapid Energy-Efficient Manufacturing of Multifunctional Polymers and Composites
Speaker: Dr. Nancy R. Sottos
Time: 6/3, 11AM-12PM EST.
Please go to https://www.purdue.edu/cmsc/events/2020-webinars/ to register for this webinar.
In situ dendrite reinforced Bulk Metallic Glass matrix composites (BMGCs) are known to overcome poor ductility and fracture response exhibited by monolithic bulk metallic glasses (BMGs). In this paper (Shear fracture in bulk metallic glass composites) recently published by our group in Acta Materialia, we report mode I and mode II fracture experiments on the above in situ BMGCs containing transforming and non-transforming dendrites.
How can we induce twist in tubular structures without applying a torque?
In nature, such behavior is enabled by material anisotropy. In our new work, we show that isotropic bi-layer tubes with twist incompatible layers can twist upon inflation and extension.
Interestingly, the direction of twist can spontaneously reverse as the load increases!
Check out our new paper at EML:
https://www.sciencedirect.com/science/article/pii/S2352431621000766
Dear colleagues,
We invite you to see the preprint of our new paper "Flexoelectricity in soft elastomers and the molecular mechanisms underpinning the design and emergence of giant flexoelectricity" that will appear in PNAS. Here we present a molecular-to-continuum scale theory for the flexoelectric effect in elastomers. The theory unveils a mechanism for achieving giant flexoelectricity--which finds support in prior experimental results; it is then leveraged for designing elastomers for 1) piezoelectricity, 2) tuning the direction of flexoelectricity, and 3) flexoelectricity which is invariant with respect to spurious deformations (https://doi.org/10.1073/pnas.2102477118).
In classical plasticity models, the physical length scale is not considered to control the size effects. Strain gradient plasticity models include one or more length scales that control size effects. Stress gradient plasticity model is introduced with a specific physical length scale and does not include any additional parameters.
The recent literature of finite eignestrains in nonlinear elastic solids is reviewed, and Eshelby's inclusion problem at finite strains is revisited. The subtleties of the analysis of combinations of finite eigenstrains for the example of combined finite radial, azimuthal, axial, and twist eigenstrains in a finite circular cylindrical bar are discussed. The stress field of a spherical inclusion with uniform pure dilatational eigenstrain in a radially-inhomogeneous spherical ball made of arbitrary incompressible isotropic solids is analyzed.
Transverse wrinkles usually emerge in a uniaxially stretched elastic film and can be suppressed upon further tension, which is an instability-restabilization behavior due to the nonlinear competition between stretching energy and bending energy. Here, we show that curvature can effectively and precisely tune the wrinkling localization and amplitude.
We are currently investigating the shock response of materials using molecular dynamics (MD). This project showed us that the preparation of properly equilibrated MD models can be very challenging even for someone with a strong background in molecular modeling. Therefore, we thought of sharing some of our recent MD models with the research community. We would like to share the LAMMPS input and data files required to run MD simulation of shock wave propagation and ballistic impacts. The two MD models are shown above.
