research

Meng, Z., Liu, M., Yan, H., Genin, G. M., & Chen, C. Q.* (2022). Deployable mechanical metamaterials with multistep programmable transformation. Science Advances, 8(23), eabn5460.

Mao, J. J.*, Wang, S., Tan, W.*, & Liu, M.* (2022). Modular multistable metamaterials with reprogrammable mechanical properties. Engineering Structures, 272, 114976.

Zhang, Y., Yang, J., Liu, M.*, & Vella, D. (2022). Shape-morphing structures based on perforated kirigami. Extreme Mechanics Letters, 56, 101857.

In this paper we discuss nonlinear anisotropic anelasticity formulated based on the two multiplicative decompositions F=FeFa and F=FaFe. Using the Bilby-Kroner-Lee decomposition F=FeFa one can define a Riemannian material manifold (the natural configuration of an anelastic body) whose metric explicitly depends on the anelastic deformation Fa.

Dear Colleagues, Our recent publication on the Journal of Applied Mechanics:

https://doi.org/10.1016/j.jmps.2022.105031

Abstract

We introduce a generalized methodology to uncover all mechanical couplings in 2D lattice geometries by obtaining the decoupled micropolar elasticity tensor. We also correlate the mechanical couplings with the point groups of 2D lattices by applying the symmetry operation to the decoupled micropolar elasticity tensor. The decoupled micropolar constitutive equation reveals eight mechanical coupling effects in planar solids, four of which are discovered for the first time in the mechanics' community.

I would like to draw your attention to our recently proposed predictive method based on a semi-empirical model (LEFM) and Neural Network, exploiting the Physics-informed Machine Learning concept. We show how the accuracy of state-of-the-art fatigue predictive models, based on defects present in materials, can be significantly boosted by accounting for additional morphological features via Physics-Informed Machine Learning.

Jie Ma, Daochen Yin, Zhi Sheng, Jian Cheng, Zheng Jia*, Teng Li, Shaoxing Qu, Delayed Tensile Instabilities of Hydrogels, Journal of the Mechanics and Physics of Solids, 168, 105052 (2022)

Highlights

• A finite-deformation crystal-elastic membrane model for TMD monolayers is presented.

• Strains of the middle surface and two normal-stretches describe the deformation.

• The continuum hyperelastic strain energy is obtained from an interatomic potential.

• The present model matches well with the purely atomistic simulations.

Abstract

The homogenized constitutive models that have been utilized to simulate the behavior of nanostructures are typically based on the Cauchy–Born hypothesis, which seeks the fundamental properties of material via relating atomistic information to an assumed homogeneous deformation field. It is well known that temperature has a profound effect on the validity and size-dependency of the Cauchy-Born hypothesis in finite deformations.

Renheng Bo, Shunze Cao, and Yihui Zhang

Department of Engineering Mechanics, Tsinghua University

1. Introduction

Large deformation of shape-memory polymer-based lattice metamaterials. International Journal of Mechanical Sciences (2022) 107593  

The Applied Mechanics Executive Committee (AMD-EC) is pleased to announce the 2022 IMECE student travel award competition, which is sponsored by the Haythornthwaite Foundation*.

This article addresses the interaction of two coaxial cylinders separated by a thin fluid layer. The cylinders are flexible, have a finite length, and are subject to a vibration mode of an Euler–Bernoulli beam. Assuming a narrow channel, an inviscid and linear theoretical approach is carried out, leading to a new simple and tractable analytical expression of the fluid forces.

Hard-magnetic soft materials have attracted broad interests because of their flexible programmability, non-contact activation and rapid response in various applications such as soft robotics, biomedical devices and flexible electronics. Such multifunctional materials consist of a soft matrix embedded with hard-magnetic particles, and can exhibit large deformations under external magnetic stimuli. Here, we develop a three-dimensional (3D) rod model to predict spatial deformations (extension, bending and twist) of slender hard-magnetic elastica.

May a double restabilization of the trivial path occurr at monotonically increasing compression force?

May movable constraints be exploited to attain target force–displacement curves?

Dear colleagues, 

We recently pablished a paper titled "Multiscale design of nonlinear materials using reduced-order modeling", which might be interesting to you. The paper is freely accessible by this link through 09/24/2022 on Elsiver, and an author's copy is here. The abstract is attached below. Thank you for your interest. 

Dear Colleague, 

I'm pleased to announce our latest paper on configurational mechanics has just appeared in Acta Mechanica:

Nathaniel N. Goldberg and Oliver M. O’Reilly. A Material Momentum Balance Law for Shells and Plates with Application to Phase Transformations and Adhesion. Acta Mechanica, 2022.

Open Access is kindly provided by UC Berkeley Library.

Dear All,

I am excited to share that we recently developed iVABS as an integrated VABS-based framework for design and optimization, parametric studies, uncertainty quantifications of composite rotor blades, and other beam-like structures. This tool is particularly useful for rapid design of composite slender structures with accuracy of detailed 3D FEA at the speed of simple engineering beam theories.