8 results match your criteria Acta Mechanica[Journal]

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Doppler effect described by the solutions of the Cattaneo telegraph equation.

Acta Mech 2021 Feb 30;232(2):725-740. Epub 2020 Nov 30.

Department of Mechanical Science and Engineering, Beckman Institute and Institute for Condensed Matter Theory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.

The Cattaneo telegraph equation for temperature with moving time-harmonic source is studied on the line and the half-line domain. The Laplace and Fourier transforms are used. Expressions which show the wave fronts and elucidate the Doppler effect are obtained. Read More

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February 2021

Belt-pulley interaction: role of the action line of friction forces.

Authors:
Evgenii Oborin

Acta Mech 2020 27;231(9):3979-3987. Epub 2020 Jun 27.

Institute of Technical Mechanics, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria.

A simplified model of the belt motion with small strains is proposed. The main purpose of the modeling is to show the effects arising when the line of action of friction forces is shifted to the belt's middle axis. The prestressed shearable model of the belt is used in this study. Read More

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Application-oriented fundamental research on concrete and reinforced concrete structures: selected findings from an Austro-Chinese research project.

Acta Mech 2020 12;231(6):2231-2255. Epub 2020 Mar 12.

Institute for Mechanics of Materials and Structures, TU Wien - Vienna University of Technology, Karlsplatz 13/202, 1040 Vienna, Austria.

In this paper, the significance of application-oriented fundamental research on concrete and reinforced concrete structures for progress regarding practical applications to structural design is addressed based on four examples. They were treated in a joint research project of Vienna University of Technology and Tongji University. The first topic refers to sudden heating or cooling of concrete structures, the second one to high-dynamic strength of specimens made of cementitious materials, the third one to structural analysis of segmental tunnel rings used in mechanized tunneling, and the fourth one to serviceability and ultimate limit states of concrete hinges used in integral bridge construction. Read More

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Measurement in opaque flows: a review of measurement techniques for dispersed multiphase flows.

Authors:
Christian Poelma

Acta Mech 2020 13;231(6):2089-2111. Epub 2020 May 13.

Multiphase Systems (3ME-P&E), Delft University of Technology, Leeghwaterstraat 21, 2628 CA Delft, The Netherlands.

A review is presented of measurement techniques to characterise dispersed multiphase flows, which are not accessible by means of conventional optical techniques. The main issues that limit the accuracy and effectiveness of optical techniques are briefly discussed: cross-talk, a reduced signal-to-noise ratio, and (biased) data drop-out. Extensions to the standard optical techniques include the use of fluorescent tracers, refractive index matching, ballistic imaging, structured illumination, and optical coherence tomography. Read More

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On proportional deformation paths in hypoplasticity.

Acta Mech 2020 28;231(4):1603-1619. Epub 2020 Jan 28.

2Institute for Mathematics and Scientific Computing, University of Graz, NAWI Graz, Heinrichstr. 36, 8010 Graz, Austria.

We investigate rate-independent stress paths under constant rate of strain within the hypoplasticity theory of Kolymbas type. For a particular simplified hypoplastic constitutive model, the exact solution of the corresponding system of nonlinear ordinary differential equations is obtained in analytical form. On its basis, the behaviour of stress paths is examined in dependence of the direction of the proportional strain paths and material parameters of the model. Read More

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January 2020

Steady state motion of a shear deformable beam in contact with a traveling surface.

Acta Mech 2019 9;230(11):4021-4033. Epub 2019 Aug 9.

2Institute of Mechanics and Mechatronics, Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria.

A shear deformable beam moving along a straight path is considered as an idealization of the problem of stationary operation of a belt drive. The partial contact with a traveling surface results in the shear deformation of the beam. The tangential contact force grows near the end of the contact zone. Read More

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Analysis of pole acceleration in spatial motions by the generalization of pole changing velocity.

Authors:
Gábor Csernák

Acta Mech 2019 9;230(7):2607-2624. Epub 2019 May 9.

1Department of Applied Mechanics, Budapest University of Technology and Economics, Budapest, Hungary.

It is well known in planar kinematics of rigid bodies that the acceleration of the material point coinciding with the instantaneous center of rotation (or pole) is perpendicular to the so-called pole changing velocity. In the present paper, the concept of pole changing velocity is generalized to spatial motions. Using this result, the acceleration of the material points along the instantaneous screw axis can be expressed in a straightforward way, without the tools of advanced differential geometry. Read More

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Hypoelastic Soft Tissues: Part II: In-Plane Biaxial Experiments.

Acta Mech 2010 Aug;213(1-2):205-222

Clifford H. Spicer Chair in Engineering, Saginaw Valley State University, 202 Pioneer Hall, 7400 Bay Road, University Center, MI 48710, Tel.: 1-989-964-2288.

In Part I, a novel hypoelastic framework for soft-tissues was presented. One of the hallmarks of this new theory is that the well-known exponential behavior of soft-tissues arises consistently and spontaneously from the integration of a rate based formulation. In Part II, we examine the application of this framework to the problem of biaxial kinematics, which are common in experimental soft-tissue characterization. Read More

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