# Igor Emri
Igor Emri (born 1952) is a Slovenian engineer and scientist in the mechanics of materials, a retired Chair Professor of Mechanics at the University of Ljubljana's Faculty of Mechanical Engineering, and an International Member of the United States National Academy of Engineering, elected in 2020.[1](https://www.ias.si/en/igor-emri) • [2](https://www.linkedin.com/in/prof-dr-igor-emri-a91a675) With Wolfgang G. Knauss of the [California Institute of Technology](https://www.edgepedia.org/california-institute-of-technology), he is regarded as a pioneer of mechanics of time-dependent materials. He developed the Knauss-Emri model for the non-linear behavior of such materials and co-founded the field as an organized discipline in 1993.[1](https://www.ias.si/en/igor-emri) • [3](https://www.fs.uni-lj.si/en/press-releases/the-book-advances-in-mechanics-of-time-dependent-materials-is-published-by-springer/)
| Fact | Detail |
|---|---|
| Born | Murska Sobota, Slovenia, 1952[1](https://www.ias.si/en/igor-emri) |
| Doctorate | 1981, mechanics of time-dependent materials, California Institute of Technology / University of Ljubljana[1](https://www.ias.si/en/igor-emri) |
| Field | Experimental mechanics of polymeric, time-dependent materials[4](https://cris.cobiss.net/ecris/si/sl/researcher/5090) |
| Known for | Knauss-Emri model; time-temperature-pressure superposition; co-founding mechanics of time-dependent materials (1993)[1](https://www.ias.si/en/igor-emri) • [3](https://www.fs.uni-lj.si/en/press-releases/the-book-advances-in-mechanics-of-time-dependent-materials-is-published-by-springer/) • [5](https://civil.csu.edu.cn/info/1005/10458.htm) |
| NAE membership | International Member, elected 2020[2](https://www.linkedin.com/in/prof-dr-igor-emri-a91a675) |
| Journal role | Editor of Springer's Mechanics of Time-Dependent Materials since its 1997 launch[3](https://www.fs.uni-lj.si/en/press-releases/the-book-advances-in-mechanics-of-time-dependent-materials-is-published-by-springer/) • [1](https://www.ias.si/en/igor-emri) |
| Patents | EP 12006059 (A1, 2014) and EP2700838 (B1, 2015), vibro-acoustic insulation[1](https://www.ias.si/en/igor-emri) |
| Bibliography | More than 300 co-authored works[3](https://www.fs.uni-lj.si/en/press-releases/the-book-advances-in-mechanics-of-time-dependent-materials-is-published-by-springer/) |
## Education and academic career
Emri was born in Murska Sobota, Slovenia, in 1952. He earned a degree in mechanics at the University of Ljubljana in 1974 and a master's degree in 1977; his 1981 doctorate, on the mechanics of time-dependent materials, was completed through the California Institute of Technology together with the University of Ljubljana. The Slovenian research registry SICRIS records his fields as experimental mechanics and polymeric materials.[1](https://www.ias.si/en/igor-emri) • [4](https://cris.cobiss.net/ecris/si/sl/researcher/5090)
At [Ljubljana](https://www.edgepedia.org/ljubljana) he became assistant professor in 1983, visiting scientist at Caltech in 1985, and full professor in 1996, eventually holding the Chair of Mechanics; his LinkedIn profile records that he is a retired Chair Professor of Mechanics at the Faculty of Mechanical Engineering, University of Ljubljana.[1](https://www.ias.si/en/igor-emri) • [2](https://www.linkedin.com/in/prof-dr-igor-emri-a91a675)
## Research: time-dependent materials and the Knauss-Emri model
Emri's early contribution, the Knauss-Emri model, is a theoretical-experimental approach to the non-linear viscoelastic behavior of such materials; the IAS profile links it to a 1981 publication in Computers & Structures (volume 13, pages 123-128).[1](https://www.ias.si/en/igor-emri)
In 1993 Emri and Wolfgang G. Knauss founded mechanics of time-dependent materials as a section of the (American) Society for Experimental Mechanics, and the field's first international conference was held in Ljubljana in 1995. When Springer launched the journal Mechanics of Time-Dependent Materials in 1997, Emri became its editor, a role he has held since, listed by the European Academy of Sciences and Arts as founder and Editor-in-Chief. His bibliography exceeds 300 co-authored works, and a Springer volume, Advances in Mechanics of Time-Dependent Materials (13 chapters, 247 pages), was dedicated to his 70th birthday.[3](https://www.fs.uni-lj.si/en/press-releases/the-book-advances-in-mechanics-of-time-dependent-materials-is-published-by-springer/) • [1](https://www.ias.si/en/igor-emri)
A second line of work concerns superposition principles. A lecture announcement by Central South University describing his patented technology explains the mechanism: by proper selection of the damping material and of the hydrostatic pressure applied during loading, a material's maximum damping can be matched to the frequency or rate of the applied loading. This pressure-frequency superposition is claimed to allow damping elements and sound insulation that surpass existing ones by several orders of magnitude.[5](https://civil.csu.edu.cn/info/1005/10458.htm) The announced applications span industrial machine vibration supports, vibro-seismic isolation for buildings and bridges, energy-absorbing systems for cable bridges, passive car safety, and railway couplers for cargo trains traveling beyond 300 km/h.[5](https://civil.csu.edu.cn/info/1005/10458.htm) The orders-of-magnitude claim in the lecture announcement is a promotional figure; the peer-reviewed 2023 study discussed below reports a measured improvement of up to 400% relative to the same material in bulk form.[7](https://doi.org/10.3390/polym15051299)
## Key publications
The works below are drawn from ORCID and Crossref/iCite records for the name Igor Emri. The 2021 plankton paper carries a caveat discussed in the next section.
**Granular damping (2023).** In Polymers, Emri and co-authors studied tubular specimens filled with thermoplastic polyurethane granules in Shore 90A and 75A hardness grades and introduced a combined energy parameter to evaluate damping performance together with weight-to-stiffness ratio. Granular form gave up to 400% better vibration-damping performance than the bulk material. Mechanistically, the paper attributes this to two complementary effects: pressure-frequency superposition operating at the molecular scale, which dominates at high prestress, and physical interactions between granules forming a force-chain network at the macro scale, which dominates at low prestress.
**Bitumen and roofing viscoelasticity.** A 2017 paper in Construction and Building Materials determined linear viscoelastic creep compliance and retardation spectra of bitumen-impregnated fiberglass mat and polymer-modified bitumen (about 12 citations per Crossref); a 2018 SEM conference chapter derived time-temperature superposition and Prony series coefficients for asphalt roof shingle material from creep testing.[8](https://doi.org/10.1016/j.conbuildmat.2017.08.030) • [9](https://doi.org/10.1007/978-3-319-63393-0_6) Neither abstract is available in the retrieved records, so their specific findings are not summarized here.
**Inverse methods and processing.** A 2017 paper in Mechanics of Time-Dependent Materials applied neural networks to determine the relaxation modulus of time-dependent materials (about 4 citations per Crossref).[10](https://doi.org/10.1007/s11043-016-9332-x) A 2018 Materials Today: Proceedings paper presented a new methodology for measuring the flowability of granular materials, relevant to [powder injection molding](https://www.edgepedia.org/powder-injection-molding) (about 2 citations per Crossref).[11](https://doi.org/10.1016/j.matpr.2018.08.137)
**Membranes (2018).** A Journal of Membrane Science paper examined the mechanical properties and drug permeability of PA6 membranes prepared by immersion precipitation (about 7 citations per Crossref).[12](https://doi.org/10.1016/j.memsci.2018.05.022)
**Attribution caveat.** ORCID and Crossref list a 2021 Journal of Plankton Research paper, The rôles of plankton and neuston microbial organic matter in climate regulation (about 9 citations per Crossref), under the name Igor Emri.[13](https://doi.org/10.1093/plankt/fbab067) The Ljubljana professor's [Google Scholar](https://www.edgepedia.org/google-scholar) profile, which otherwise covers his viscoelasticity oeuvre, does not include it, so the paper most likely belongs to a different person of the same name; its attribution is unresolved and it should not be counted among the NAE member's works.[14](https://scholar.google.co.ve/citations?hl=en&user=45eNXJkAAAAJ) The same caution applies to a 2007 Soft Matter paper on anisotropic polymer brushes, a molecular-dynamics study whose subject is distant from his experimental mechanics record (about 2 citations per iCite).[15](https://doi.org/10.1039/b711649g)
## Applied and biomedical directions
Emri's laboratory has carried its results into engineering through Slovenian projects recorded in SICRIS: nanostructured electrospun fiber materials for targeted deposition of pharmaceutical ingredients (2016-2019), flowability of nano powders for injection molding (2014-2017), vibro-acoustic structural elements based on waste tires (2009-2012), and nanostructured polymer implants in medicine (2008-2011).[4](https://cris.cobiss.net/ecris/si/sl/researcher/5090) The high-pressure force-network technology itself is protected by European patents EP 12006059 (A1, 2014) and EP2700838 (B1, 2015), granted by the European Patent Office in Munich for a vibro-acoustic insulation advance.[1](https://www.ias.si/en/igor-emri) He also founded the consulting company EMRI d.o.o.[2](https://www.linkedin.com/in/prof-dr-igor-emri-a91a675)
## Honours and recognition
In 2020 Emri was elected an International Member of the US National Academy of Engineering; the Central South University announcement paraphrases the grounds as experimental and theoretical contributions to the mechanics of time-dependent materials and new sound and vibration insulation materials, and he attended the diploma ceremony in his capacity as a full member of the European Academy of Sciences and Arts.[5](https://civil.csu.edu.cn/info/1005/10458.htm) • [6](https://www.ias.si/novice-sl/redni-lan-ias-prof-dr-igor-emri-prejel-diplomo-mednarodnega-lana-national-academy-of-engineering-of-the-usa) He is a fellow of the Society of Experimental Mechanics (USA), the [Russian Academy of Engineering](https://www.edgepedia.org/russian-academy-of-engineering), the Russian Academy of Natural Sciences, the European Academy of Sciences, and Arts, the European Academy of Sciences, and the [Slovenian Academy of Sciences and Arts](https://www.edgepedia.org/slovenian-academy-of-sciences-and-arts), and has served as president of SEM and of the International Committee on Rheology and as chair of the Science Europe Scientific Committee on Engineering.[1](https://www.ias.si/en/igor-emri)
## References
1. Igor Emri — member profile, European Academy of Sciences and Arts. https://www.ias.si/en/igor-emri
2. Igor Emri, LinkedIn profile. https://www.linkedin.com/in/prof-dr-igor-emri-a91a675
3. "The book Advances in Mechanics of Time-Dependent Materials is published by Springer", University of Ljubljana Faculty of Mechanical Engineering. https://www.fs.uni-lj.si/en/press-releases/the-book-advances-in-mechanics-of-time-dependent-materials-is-published-by-springer/
4. SICRIS researcher record, dr. Igor Emri (no. 04316). https://cris.cobiss.net/ecris/si/sl/researcher/5090
5. "Time-Temperature-Pressure Superposition", lecture announcement, Central South University. https://civil.csu.edu.cn/info/1005/10458.htm
6. "Prof. dr. Igor Emri received the diploma of International Member of the National Academy of Engineering of the USA", European Academy of Sciences and Arts news. https://www.ias.si/novice-sl/redni-lan-ias-prof-dr-igor-emri-prejel-diplomo-mednarodnega-lana-national-academy-of-engineering-of-the-usa
7. On the Vibration-Damping Properties of the Prestressed Polyurethane Granular Material, Polymers (2023). https://doi.org/10.3390/polym15051299
8. Linear viscoelastic creep compliance and retardation spectra of bitumen impregnated fiberglass mat and polymer modified bitumen, Construction and Building Materials (2017). https://doi.org/10.1016/j.conbuildmat.2017.08.030
9. Time temperature superposition and Prony series coefficients of asphalt roof shingle material, SEM Conference Proceedings (2018). https://doi.org/10.1007/978-3-319-63393-0_6
10. Determination of relaxation modulus of time-dependent materials using neural networks, Mechanics of Time-Dependent Materials (2017). https://doi.org/10.1007/s11043-016-9332-x
11. A new methodology for measuring the flowability of granular materials, Materials Today: Proceedings (2018). https://doi.org/10.1016/j.matpr.2018.08.137
12. Mechanical properties and drug permeability of the PA6 membranes, Journal of Membrane Science (2018). https://doi.org/10.1016/j.memsci.2018.05.022
13. The rôles of plankton and neuston microbial organic matter in climate regulation, Journal of Plankton Research (2021). https://doi.org/10.1093/plankt/fbab067
14. Google Scholar profile, Igor Emri (Ljubljana). https://scholar.google.co.ve/citations?hl=en&user=45eNXJkAAAAJ
15. Computer simulation of anisotropic polymer brushes, Soft Matter (2007). https://doi.org/10.1039/b711649g
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*Topic: Encyclopedia › Technology and the built world › Engineers and computer scientists › Engineers and materials scientists › Researchers in mechanical and aerospace engineering, robotics, and control › Solid Mechanics and Materials*
*Initially written Sep 17, 2026 · Reviewed: Sep 30, 2026 · Edited: Oct 11, 2026; Oct 15, 2026 · Last review: Sep 30, 2026*
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