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arash_yavari's picture

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.

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@umn.edu.

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

Application of new orthotropic model in plane stress problems

The plane stress problems have solved by using a new orthotropic element model, compared with the finite element method, it can be found that the results of the two methods are in good agreement.
Supplemental Videos:
(1) https://www.bilibili.com/video/BV1yd4y167i6/?spm_id_from=333.999.0.0
(2) https://www.bilibili.com/video/BV1CV4y1M7y6/?spm_id_from=333.999.0.0

mohsenzaeem's picture

A Phase-Field Model for Interactive Evolution of Phase Transformation and Cracking in Super-Elastic Shape Memory Ceramics

This work presents a modified phase-field model for accurate coupling of phase transformation and cracking in shape memory ceramics. The existing phase-field models underestimate the elastic response at the beginning of the mechanical response. We modified the chemical free energy to control the rate of phase transformation and consequently obtain a physical elastic response before initiation of phase transformation. First, the forward and reverse martensitic phase transformation in a superelastic single crystal 3 mol% yttria-stabilized tetragonal zirconia is studied.

Wenbin Yu's picture

ASME SSDM Conference

ASME Aerospace Division is launching a new conference called ASME Aerospace Structures, Structural Dynamics, and Materials (SSDM) Conference. The mission of this conference is to convene and serve the global aerospace structures, structural dynamics, and materials communities, continuing the legacy left behind by the AIAA/ASME/ASCE/AHS/ASC SDM conference. SSDM accepts two types of submissions: Paper (abstract deadline: Nov. 14) and Presentation Only (deadline: Feb. 13). The inaugural conference will be held in San Diego (June 19-21 2023).

arash_yavari's picture

On the Direct and Reverse Multiplicative Decompositions of Deformation Gradient in Nonlinear Anisotropic Anelasticity

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.

Emilio Martínez Pañeda's picture

Griffith-based analysis of crack initiation location in a Brazilian test

Dear iMechanicians, I hope that the paper below is of interest, given the wide use this experiment. Essentially, we use the generalised Griffith criterion to determine the crack initiation location in the Brazilian split test, establishing the conditions (jaws geometry and material properties) that lead to a valid test. We find that the range of conditions where the Brazilian test is valid is much narrower than previously thought, with current standards being inappropriate for a wide range of rock-like materials.

Article: Modal added-mass matrix of an elongated flexible cylinder immersed in a narrow annular fluid, considering various boundary conditions. New theoretical results and numerical validation

This paper considers the fluid–structure interaction problem of two coaxial cylinders separated by a thin layer of fluid. The flexible inner cylinder is imposed a small amplitude harmonic displacement corresponding to a dry vibration mode of an Euler–Bernoulli beam, while the external cylinder is rigid. A new theoretical formulation based on the assumption of a narrow fluid annulus is derived to estimate the modal added-mass matrix of the vibrating cylinder.

Production of Fibres from Lunar Soil: Feasibility, Applicability and Future Perspectives

The construction of a lunar base is considered to be an important step towards deep-space exploration by humanity, and will rely on the utilisation of in situ lunar resources. In this paper, we discuss the current knowledge on the feasibility of converting lunar soil to high-performance fibres that can be used for the construction of a lunar base. This fibre would be combined with further portions of lunar soil to generate fibre-reinforced composites, which is utilized as multi-functional materials for lunar base construction.

Joshua's picture

Mechanical couplings of 2D lattices uncovered by decoupled micropolar elasticity tensor and symmetry operation

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.

enrico.salvati1's picture

Defect-based Physics-Informed Machine Learning Framework for Fatigue Prediction

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.

Zheng Jia's picture

Delayed tensile instabilities of hydrogels

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)

susanta's picture

Article: An Atomistic-based Finite Deformation Continuum Membrane Model for Monolayer Transition Metal Dichalcogenides

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

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