research

Our paper on the phase-field mixture theory of tumor growth is published in JMPS. The continuum model simulates significant mechano-chemo-biological features of avascular tumor growth in the various microenvironment, i.e., nutrient concentration and mechanical stress.

Faghihi, Feng, Lima, Oden, and Yankeelov (2020). A Coupled Mass Transport and Deformation Theory of Multi-constituent Tumor Growth. Journal of the Mechanics and Physics of Solids, 103936.

Journal Club for April 2020: Curvature-Affected Instabilities in Membranes and Surfaces

Fan Xu, Fudan University

Theory of physical aging from polymer science is, for the first time, introduced to understand ACL injury and its prevention. By analogy to physical aging of amorphous polymer materials, we think physical aging of two bundles of ACL will largely increase risk of ACL injury. Besides, physical aging will also build a heterogeneous stress and strain in ACL due to its natural anatomic structure, which is a large risk for athletes. The specific designed prevention programs for ACL injury such as plyometrics, strengthening and other neuromuscular training exercises [1] are believed to erase physical aging of ACL. ACL with less physical aging is less likely to get injured in sport activities. In this article, a virtual physical aging simulation is built to validate current hypothesis. Erasing physical aging of ACL may provide an accurate and quantitative way to prevent ACL injury.

By Alexa S. Kuenstler, Yuzhen Chen, Phuong Bui, Hyunki Kim, Antonio DeSimone, Lihua Jin, Ryan C. Hayward

Abstract: Advanced machine learning methods could be useful to obtain novel insights into some challenging nanomechanical problems. In this work, we employed artificial neural networks to predict the fracture stress of defective graphene samples. First, shallow neural networks were used to predict the fracture stress, which depends on the temperature, vacancy concentration, strain rate, and loading direction.

In this paper, we formulate a theory for the coupling of accretion mechanics and thermoelasticity. We present an analytical formulation of the thermoelastic accretion of an infinite cylinder and of a two-dimensional block.

Fracture mechanics is one of the key research topics in our field (of mechanics) and has a rather rich history of innovation and applications. From earth-quakes to air-planes---the mechanics underpinning the phenomenon of materials falling apart has been essential in the development of technology.  Griffith’s work on fracture was published about a 100 years ago and is often widely regarded as the start of modern fracture mechanics.

Engineering ceramic/nanocomposite interfaces may lead to the development of ultra-tough ceramic nanocomposites. The novel processing method, as well as micromechanical interpretation of the above result, can be found here: https://doi.org/10.1016/j.carbon.2020.02.075

Christos E. Athanasiou

S. Thomas, A. Kulangara Madam, and M. Asle Zaeem. Stone-Wales defect induced performance improvement of BC3 monolayer for high capacity lithium-ion rechargeable battery anode applications. The Journal of Physical Chemistry C (2020) (10 pages). 

http://dx.doi.org/10.1103/PhysRevMaterials.4.033602

Abstract

Dear iMechanicians,

I hope this paper is of interest to you. We show that quasi-Newton methods make monolithic phase field fracture implementations very robust. Convergence and computations times orders of magnitude smaller than the usual staggered approaches are demonstrated in complex problems such as unstable cracking, fatigue or dynamic crack branching.

https://pubs.acs.org/doi/abs/10.1021/acsbiomaterials.9b01983

This is the preprint of an article that will appear in Computer Methods in Applied Mechanics and Engineering (https://doi.org/10.1016/j.cma.2020.112946).

Effective Response of Heterogeneous Materials using the Recursive Projection Method

Cyclic Plasticity of the As-Built EOS Maraging Steel: Preliminary Experimental and Computational Results

https://www.mdpi.com/2076-3417/10/4/1232/htm

Jian Cheng, Zheng Jia*, Teng Li*, A constitutive model of microfiber reinforced anisotropic hydrogels: with applications to wood-based hydrogels, Journal of the Mechanics and Physics of Solids, 138 (2020) 103893 (DOI: https://doi.org/10.1016/j.jmps.2020.103893)

Journal Club for March 2020: Molecular Simulation-Guided and Physics-Informed Multiscale Modeling of Polymer Viscoelasticity

Ying Li, Department of Mechanical Engineering, University of Connecticut

1.       Introduction

MDPI- Sustainability:  Special Issue "Sustainability of Additive Manufacturing and 3D-printed Parts"

https://www.mdpi.com/journal/sustainability/special_issues/AdditiveManufacturing_3D-printedParts

Submission deadline :30 June 2020

This is our recent work on the design of fatigue-resistant hydrogel adhesion. In this work, we show that fatigue-resistant hydrogel adhesion can be achieved by anchoring ordered nanocrystalline domains at the interface. This method is applicable to glass, ceramic, titanium, aluminum, stainless steel, and even elastomers including PU and PDMS. We also demonstrate its potential applications as endurant hydrogel coatings for versatile engineering materials with complex geometries.

Chiqun Zhang         Amit Acharya        Alan C Newell          Shankar C Venkataramani

Defects, a ubiquitous feature of ordered media, have certain universal features, independent of the underlying physical system, reflecting their topological, as opposed to energetic properties. We exploit this universality, in conjunction with smoothing defects by "spreading them out," to develop a modeling framework and associated numerical methods that are applicable to computing energy driven behaviors of defects across the amorphous-soft-crystalline materials spectrum. Motivated by ideas for dealing with elastic-plastic solids with line defects, our methods can handle order parameters that have a head-tail symmetry, i.e. director fields, in systems with a continuous translation symmetry, as in nematic liquid crystals, and in systems where the translation symmetry is broken, as in smectics and convection patterns. We illustrate our methods with explicit computations.

Preprint

The Hector Fellow Academy offers you the opportunity to realize a self-developed research project under supervision Prof. Peter Gumbsch. He is one of the Hector Fellows, a community of outstanding professors from different research institutions across Germany working in STEM-subjects, medicine, and psychology.

The extraordinary mechanical properties of graphene were measured on very small or supported samples. In our new paper published in Nature Communications, by developing a protocol for sample transfer, shaping and straining, we report the outstanding elastic properties and stretchability of free-standing single-crystalline monolayer graphene under in situ tensile tests.