research
Phase field modelling of fracture and fatigue in Shape Memory Alloys
Dear iMechanicians. I hope that the following paper is of interest to you. We develop the first phase field formulation for fracture (and fatigue) in Shape Memory Alloys. Its potential is demonstrated by solving a variety of paradigmatic 2D and 3D boundary value problems, from R-curves to fatigue cracking of a NiTi biomedical stent.
M. Simoes, E. Martínez-Pañeda. Phase field modelling of fracture and fatigue in Shape Memory Alloys. Computer Methods in Applied Mechanics and Engineering 373 (2021) 113504
EML Webinar on 4 November 2020 on Topological adhesion, wet and elastic by Zhigang Suo
EML Webinar on 4 November 2020 will be given by Zhigang Suo, Harvard University. Discussion leader: Jimmy Hsia, Nanyang Technological University
Title: Topological adhesion, wet and elastic
Time: 9:30 am Boston, 2 pm London, 3 pm Paris, 10:30 pm Beijing on 4 November 2020
New results on shock mitigation of MC gels to appear in JMPS
This recently accepted paper, to appear in the Journal of the Mechanics and Physics of Solids, reports our detailed experiments on shock energy absorption of methylcellulose hydrogels. A phenomenological model is developed and validated that allows for a quantitative estimate of the attnuated signal as a function of the gel layer thickness and composition.
Flower Inspiration: Broad-angle Structural Color through Tunable Hierarchical Wrinkles in Thin Film Multilayers
Dear colleagues, we have our recent paper, Flower Inspiration: Broad-angle Structural Color through Tunable Hierarchical Wrinkles in Thin Film Multilayers, published on Advanced Functional Materials. The cuticular nano-ridges on certain flower petals can selectively display broad-angle iridescence to enhance pollinators’ foraging efficiency. This paper develops a tunable broad-angle diffracting surface based on hierarchical wrinkling composites.
Numerical and experimental analysis of the bi-stable state for frictional continuous system
Friction induced vibrations are a very well known problem in engineering applications. Sometimes they are referred to be unpredictable, intermittent, capricious (!!!) and particularly experimentalists know this very well. Here, by means of numerical simulations and experimental measurements, we highlight how capriciousness may arise from the multistable behavior of frictional systems, i.e. their characteristic to show multiple stable solutions for the same set of governing parameters. Hence initial conditions and perturbations become crucial.
How contact area decreases under shear load in soft bodies?
A very good paper has just been published in JMPS by J.C. Mergel, J. Scheibert, R.A. Sauer "Contact with coupled adhesion and friction: Computational framework, applications, and new insights". it shows the results of numerical simulations with soft bodies sheared by a tangential force. There is a vivacious discussion in Literature if the contact area reduces due to adhesion or due to large deformation.
Invitation to attend Mr. Ran Tao PhD defense at COHMAS lab, KAUST.
Title:
Enhancing the bonding of CFRP adhesive bonding through laser-based surface preperation sterategies.
Abstract:
Carbon Fiber-Reinforced Polymers (CFRPs) have been widely applied in the aerospace and automotive industries to achieve unprecedented weight reductions. However, major challenges need to be solved in order to exploit their full potential, especially in the design of full composite primary structure, making then a vital part of the mobility and energy revolution.
A finite element formuation for a direct approach to elastoplasticity in special Cosserat rods
A finite element formulation is presented for a direct approach to model elastoplastic deformation in slender bodies using the special Cosserat rod theory. The direct theory has additional plastic strain and hardening variables, which are functions of just the rod's arc-length, to account for plastic deformation of the rod. Furthermore, the theory assumes the existence of an effective yield function in terms of stress resultants, i.e., force and moment in the cross-section and cross-section averaged hardening parameters.