research
Buckling of viscoelastic spherical shells
By Tianzhen Liu, Yuzhen Chen, John W. Hutchinson, Lihua Jin
An electroelastic Kirchhoff rod theory incorporating free space electric energy
This work presents a geometrically exact Kirchhoff-like electroelastic rod theory wherein the contribution of free space energy is also factored in. In addition to the usual mechanical variables such as the rod's centerline and cross-section orientation, three electric potential parameters are also introduced to account for the variation in electric potential within the rod's cross-section as well as along the rod length. The free space energy is included through an electric flux-like variable acting on the lateral surface of the rod.
Isogeometric Shape Optimization of Auxetics with Prescribed Nonlinear Deformation
Graphical Abstract (from Publication 2 below):
Abstract:
Snap-induced morphing: From a single bistable shell to the origin of shape bifurcation in interacting shells
Liu, M., Domino, L., de Dinechin, I. D., Taffetani, M., & Vella, D.* (2023). Snap-induced morphing: From a single bistable shell to the origin of shape bifurcation in interacting shells. J Mech. Phys. Solids, 170, 105116.
Accretion Mechanics of Nonlinear Elastic Circular Cylindrical Bars Under Finite Torsion
In this paper we formulate the initial-boundary value problem of accreting circular cylindrical bars under finite torsion. It is assumed that the bar grows as a result of printing stress-free cylindrical layers on its boundary while it is under a time-dependent torque (or a time-dependent twist) and is free to deform axially. In a deforming body, accretion induces eigenetrains, and consequently residual stresses. We formulate the anelasticity problem by first constructing the natural Riemannian metric of the growing bar.
Enhancing the fracture resistance of hydrogels by regulating the energy release rate via bilayer designs: Theory and experiments
Yijie Cai, Jie Ma, Zihang Shen, Xianmin Shao, Zheng Jia *, Shaoxing Qu, Enhancing the fracture resistance of hydrogels by regulating the energy release rate via bilayer designs: Theory and experiments, Journal of the Mechanics and Physics of Solids, 170, 105125 (2023)
Two Funded PhD positions at University of Minnesota, Twin Cities
Multiscale mechanics and extreme materials lab (https://z.umn.edu/ravi-research-lab) at the University of Minnesota Twin Cities has two fully funded Ph.D. positions starting in fall 2023. Interested candidates may reach out to sravi [at] umn.edu (sravi[at]umn[dot]edu). The research will be on two main topics
Chiral topographic instability in shrinking spheres
Many biological structures exhibit intriguing morphological patterns adapted to environmental cues, which contribute to their important biological functions and also inspire material designs. Here, we report a chiral wrinkling topography in shrinking core–shell spheres, as observed in excessively dehydrated passion fruit and experimentally demonstrated in silicon core–shells under air extraction. Upon shrinkage deformation, the surface initially buckles into a buckyball pattern (periodic hexagons and pentagons) and then transforms into a chiral mode.
Solution of plane strain problems based on a new model
For orthotropic plane strain problems, the various existing calculation methods are very complex. The orthotropic plane strain problem with cracks have solved by using a new element model, and compared with the finite element method, it can be found that the displacements and the stresses of the two methods are in good agreement.
Supplemental Videos:
(1) https://www.bilibili.com/video/BV1QW4y1e7YQ/?spm_id_from=333.999.0.0