Analytical and Experimental Analysis of Stress Uniformity in Specimen During Direct Impact Hopkinson Bar Test

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21260%2F22%3A00364083" target="_blank" >RIV/68407700:21260/22:00364083 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.21495/512109" target="_blank" >https://doi.org/10.21495/512109</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.21495/512109" target="_blank" >10.21495/512109</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Analytical and Experimental Analysis of Stress Uniformity in Specimen During Direct Impact Hopkinson Bar Test

Popis výsledku v původním jazyce

Stress uniformity in a specimen represents a crucial parameter for validity of impact experiment conducted in a split Hopkinson bar. Principle of the experimental method is to measure elastic stress waves that propagate in the bars of an experimental setup and to calculate stress to strain relations at the interfaces with the specimen. However, standard procedure to evaluate the experiment can only be valid when stress is distributed approximately uniformly along the specimen. As the stress wave has to propagate through the specimen during the experiment, a time period of significantly non-uniform stress distribution is present and a certain number of wave transits is required to achieve approximately uniform stress distribution. In this paper, a simple analytical model assuming one-dimensional wave propagation theory, non-equal mechanical impedance of the bars and linear elastic material model of the specimen is introduced to determine a number of transits required to achieve uniform stress distribution in the specimen. Potential of the calculated results is discussed in an experiment using a direct impact Hopkinson bar and a material with significant plateau in its stress-strain response.

Název v anglickém jazyce

Analytical and Experimental Analysis of Stress Uniformity in Specimen During Direct Impact Hopkinson Bar Test

Popis výsledku anglicky

Stress uniformity in a specimen represents a crucial parameter for validity of impact experiment conducted in a split Hopkinson bar. Principle of the experimental method is to measure elastic stress waves that propagate in the bars of an experimental setup and to calculate stress to strain relations at the interfaces with the specimen. However, standard procedure to evaluate the experiment can only be valid when stress is distributed approximately uniformly along the specimen. As the stress wave has to propagate through the specimen during the experiment, a time period of significantly non-uniform stress distribution is present and a certain number of wave transits is required to achieve approximately uniform stress distribution. In this paper, a simple analytical model assuming one-dimensional wave propagation theory, non-equal mechanical impedance of the bars and linear elastic material model of the specimen is introduced to determine a number of transits required to achieve uniform stress distribution in the specimen. Potential of the calculated results is discussed in an experiment using a direct impact Hopkinson bar and a material with significant plateau in its stress-strain response.

Druh

D - Stať ve sborníku

CEP obor

—

OECD FORD obor

20505 - Composites (including laminates, reinforced plastics, cermets, combined natural and synthetic fibre fabrics; filled composites)

Projekt

<a href="/cs/project/GM22-18033M" target="_blank" >GM22-18033M: Dynamika rázů s využitím rychlé rentgenové radiografie a zábleskového rentgenového zdroje</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2022

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

ENGINEERING MECHANICS 2022

ISBN

978-80-86246-51-2

ISSN

1805-8248

e-ISSN

1805-8256

Počet stran výsledku

4

Strana od-do

109-112

Název nakladatele

Institute of Theoretical and Applied Mechanics, AS CR

Místo vydání

Prague

Místo konání akce

Milovy

Datum konání akce

9. 5. 2022

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

—