Critical comparison of the boundary effect model with cohesive crack model and size effect law
For several decades it has been clear that the size effect on structural strength, exhibiting a major non-statistical component, is a quintessential property of all quasibrittle materials. However, progress in design codes and practice for these materials has been retarded by protracted controversie...
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ftunibolognairis:oai:cris.unibo.it:11585/812260 2024-02-11T10:08:34+01:00 Critical comparison of the boundary effect model with cohesive crack model and size effect law Carloni C. Cusatis G. Salviato M. Le J. -L. Hoover C. G. Bazant Z. P. Carloni C. Cusatis G. Salviato M. Le J.-L. Hoover C.G. Bazant Z.P. 2019 STAMPA http://hdl.handle.net/11585/812260 https://doi.org/10.1016/j.engfracmech.2019.04.036 eng eng info:eu-repo/semantics/altIdentifier/wos/WOS:000470057600014 volume:215 firstpage:193 lastpage:210 numberofpages:18 journal:ENGINEERING FRACTURE MECHANICS http://hdl.handle.net/11585/812260 doi:10.1016/j.engfracmech.2019.04.036 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85065607223 Analysis of experimental data Concrete structure Design code Energetic size effect Fracture mechanic Quasibrittle material Size effect justification Size effect law Statistical size effect info:eu-repo/semantics/article 2019 ftunibolognairis https://doi.org/10.1016/j.engfracmech.2019.04.036 2024-01-24T17:59:17Z For several decades it has been clear that the size effect on structural strength, exhibiting a major non-statistical component, is a quintessential property of all quasibrittle materials. However, progress in design codes and practice for these materials has been retarded by protracted controversies about the proper mathematical form and justification of the size effect law (SEL). A fresh exception is the American Concrete Institute which, in 2019, becomes the first concrete code-making society to adopt the SEL based on quasibrittle fracture mechanics. This article begins by discussing several long-running controversies that have recently abated, and then focuses critically on the so-called Boundary Effect Model (BEM), promoted for concrete relentlessly for two decades, in ever-changing versions, by Xiaozhi Hu et al. The BEM is here compared to the quasibrittle SEL based on asymptotic matching. Its errors, weaknesses and inconsistencies are identified—including incorrect large- and small-size asymptotic size effects, conflicts with broad-range comprehensive test data and with the cohesive crack model, incorrect aggregate-size dependence of strength, illogical dependence on ligament stress profile, inability to capture the statistical part of size effect at large sizes, simplistic effect of boundary proximity, and lack of distinction between Type 1 and 2 size effects. In contrast to the SEL, the BEM is not applicable to mixed and shear fracture modes and to complex geometries of engineering structures, and is not transplantable from concrete to other quasibrittle materials. The purpose of this critique is to help crystallize a consensus about the proper size effect formulation, not only for concrete structures but also, and mainly, for other quasibrittle materials and structures, including airframes made of fiber composites, ceramic components and micrometer-scale devices, and for failure assessments of sea ice, rock, stiff soils, bone, and various bio- or bio-mimetic materials, for all of which the ... Article in Journal/Newspaper Sea ice IRIS Università degli Studi di Bologna (CRIS - Current Research Information System) Engineering Fracture Mechanics 215 193 210 |
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Open Polar |
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IRIS Università degli Studi di Bologna (CRIS - Current Research Information System) |
op_collection_id |
ftunibolognairis |
language |
English |
topic |
Analysis of experimental data Concrete structure Design code Energetic size effect Fracture mechanic Quasibrittle material Size effect justification Size effect law Statistical size effect |
spellingShingle |
Analysis of experimental data Concrete structure Design code Energetic size effect Fracture mechanic Quasibrittle material Size effect justification Size effect law Statistical size effect Carloni C. Cusatis G. Salviato M. Le J. -L. Hoover C. G. Bazant Z. P. Critical comparison of the boundary effect model with cohesive crack model and size effect law |
topic_facet |
Analysis of experimental data Concrete structure Design code Energetic size effect Fracture mechanic Quasibrittle material Size effect justification Size effect law Statistical size effect |
description |
For several decades it has been clear that the size effect on structural strength, exhibiting a major non-statistical component, is a quintessential property of all quasibrittle materials. However, progress in design codes and practice for these materials has been retarded by protracted controversies about the proper mathematical form and justification of the size effect law (SEL). A fresh exception is the American Concrete Institute which, in 2019, becomes the first concrete code-making society to adopt the SEL based on quasibrittle fracture mechanics. This article begins by discussing several long-running controversies that have recently abated, and then focuses critically on the so-called Boundary Effect Model (BEM), promoted for concrete relentlessly for two decades, in ever-changing versions, by Xiaozhi Hu et al. The BEM is here compared to the quasibrittle SEL based on asymptotic matching. Its errors, weaknesses and inconsistencies are identified—including incorrect large- and small-size asymptotic size effects, conflicts with broad-range comprehensive test data and with the cohesive crack model, incorrect aggregate-size dependence of strength, illogical dependence on ligament stress profile, inability to capture the statistical part of size effect at large sizes, simplistic effect of boundary proximity, and lack of distinction between Type 1 and 2 size effects. In contrast to the SEL, the BEM is not applicable to mixed and shear fracture modes and to complex geometries of engineering structures, and is not transplantable from concrete to other quasibrittle materials. The purpose of this critique is to help crystallize a consensus about the proper size effect formulation, not only for concrete structures but also, and mainly, for other quasibrittle materials and structures, including airframes made of fiber composites, ceramic components and micrometer-scale devices, and for failure assessments of sea ice, rock, stiff soils, bone, and various bio- or bio-mimetic materials, for all of which the ... |
author2 |
Carloni C. Cusatis G. Salviato M. Le J.-L. Hoover C.G. Bazant Z.P. |
format |
Article in Journal/Newspaper |
author |
Carloni C. Cusatis G. Salviato M. Le J. -L. Hoover C. G. Bazant Z. P. |
author_facet |
Carloni C. Cusatis G. Salviato M. Le J. -L. Hoover C. G. Bazant Z. P. |
author_sort |
Carloni C. |
title |
Critical comparison of the boundary effect model with cohesive crack model and size effect law |
title_short |
Critical comparison of the boundary effect model with cohesive crack model and size effect law |
title_full |
Critical comparison of the boundary effect model with cohesive crack model and size effect law |
title_fullStr |
Critical comparison of the boundary effect model with cohesive crack model and size effect law |
title_full_unstemmed |
Critical comparison of the boundary effect model with cohesive crack model and size effect law |
title_sort |
critical comparison of the boundary effect model with cohesive crack model and size effect law |
publishDate |
2019 |
url |
http://hdl.handle.net/11585/812260 https://doi.org/10.1016/j.engfracmech.2019.04.036 |
genre |
Sea ice |
genre_facet |
Sea ice |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/WOS:000470057600014 volume:215 firstpage:193 lastpage:210 numberofpages:18 journal:ENGINEERING FRACTURE MECHANICS http://hdl.handle.net/11585/812260 doi:10.1016/j.engfracmech.2019.04.036 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85065607223 |
op_doi |
https://doi.org/10.1016/j.engfracmech.2019.04.036 |
container_title |
Engineering Fracture Mechanics |
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215 |
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193 |
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210 |
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1790607961052151808 |