Editing Photoelasticity (section)

==Applications==
[[File:Photoelasticity stiffener.jpg|thumb|Photoelastic model to validate the [[rigid line inclusion|stiffener]] model. Isochromatic fringe patterns around a steel platelet in a photo-elastic two-part epoxy resin.]]

Photoelasticity has been used for a variety of stress analyses and even for routine use in design, particularly before the advent of numerical methods, such as [[finite elements]] or [[boundary element method|boundary elements]].<ref>Frocht, M.M., ''Photoelasticity''. J. Wiley and Sons, London, 1965</ref> Digitization of polariscopy enables fast image acquisition and data processing, which allows its industrial applications to control quality of manufacturing process for materials such as glass<ref>{{cite journal | doi=10.1088/0957-0233/23/2/025601 | title=RGB photoelasticity applied to the analysis of membrane residual stress in glass | year=2012 | last1=Ajovalasit | first1=A. | last2=Petrucci | first2=G. | last3=Scafidi | first3=M. | journal=Measurement Science and Technology | volume=23 | issue=2 | page=025601 | bibcode=2012MeScT..23b5601A | hdl=10447/61842 | s2cid=53600215 | hdl-access=free }}</ref> and polymer.<ref>{{cite book | doi=10.1007/978-1-4419-9796-8_21 | chapter=Characterization of Mechanochemically Active Polymers Using Combined Photoelasticity and Fluorescence Measurements | title=Application of Imaging Techniques to Mechanics of Materials and Structures, Volume 4 | series=Conference Proceedings of the Society for Experimental Mechanics Series | year=2013 | last1=Kramer | first1=Sharlotte | last2=Beiermann | first2=Brett | last3=Davis | first3=Douglas | last4=Sottos | first4=Nancy | last5=White | first5=Scott | last6=Moore | first6=Jeffrey | pages=167–78 | isbn=978-1-4419-9528-5 }}</ref> [[Dentistry]] utilizes photoelasticity to analyze strain in denture materials.<ref>{{cite journal | doi=10.1016/s0109-5641(02)00019-2 | title=Reflection photoelasticity: A new method for studies of clinical mechanics in prosthetic dentistry | year=2003 | last1=Fernandes | first1=Cláudio P. | last2=Glantz | first2=Per-Olof J. | last3=Svensson | first3=Stig A. | last4=Bergmark | first4=Anders | journal=Dental Materials | volume=19 | issue=2 | pages=106–17 | pmid=12543116 }}</ref>

Photoelasticity can successfully be used to investigate the highly localized stress state within masonry<ref>{{cite journal | doi=10.1016/j.euromechsol.2009.10.009 | title=Localized stress percolation through dry masonry walls. Part I – Experiments | year=2010 | last1=Bigoni | first1=Davide | last2=Noselli | first2=Giovanni | journal=European Journal of Mechanics - A/Solids | volume=29 | issue=3 | pages=291–98 | bibcode=2010EuJMA..29..291B | url=https://hal.science/hal-00551037 }}</ref><ref>{{cite journal | doi=10.1016/j.euromechsol.2009.10.013 | title=Localized stress percolation through dry masonry walls. Part II – Modelling | year=2010 | last1=Bigoni | first1=Davide | last2=Noselli | first2=Giovanni | journal=European Journal of Mechanics – A/Solids | volume=29 | issue=3 | pages=299–307 | bibcode=2010EuJMA..29..299B | url=https://hal.science/hal-00551038 }}</ref><ref>{{cite book |last=Bigoni |first=D. |year=2012 |title=Nonlinear Solid Mechanics: Bifurcation Theory and Material Instability |publisher=Cambridge University Press |isbn=9781107025417}}</ref> or in proximity of a [[rigid line inclusion (stiffener, anticrack)|rigid line inclusion (stiffener)]]  embedded in an elastic medium.<ref>{{cite journal | doi=10.1007/s10704-010-9502-9 | title=The stress intensity near a stiffener disclosed by photoelasticity | year=2010 | last1=Noselli | first1=G. | last2=Dal Corso | first2=F. | last3=Bigoni | first3=D. | journal=International Journal of Fracture | volume=166 | issue=1–2 | pages=91–103 | s2cid=56221414 }}</ref> In the former case, the problem is nonlinear due to the contacts between bricks, while in the latter case the elastic solution is singular, so that numerical methods may fail to provide correct results. These can be obtained through photoelastic techniques. Dynamic photoelasticity integrated with high-speed photography is utilized to investigate fracture behavior in materials.<ref>{{cite journal | doi=10.1243/0309324011512658 | title=High-speed fracture studies on bimaterial interfaces using photoelasticity—a review | year=2001 | last1=Shukla | first1=A. | journal=The Journal of Strain Analysis for Engineering Design | volume=36 | issue=2 | pages=119–42 | s2cid=137504535 }}</ref> Another important application of the photoelasticity experiments is to study the stress field around bi-material notches.<ref>{{cite journal | doi=10.1016/j.matdes.2011.06.002 | title=Experimental determination of stress field parameters in bi-material notches using photoelasticity | year=2011 | last1=Ayatollahi | first1=M.R. | last2=Mirsayar | first2=M.M. | last3=Dehghany | first3=M. | journal=Materials & Design | volume=32 | issue=10 | pages=4901–08 }}</ref> Bi-material notches exist in many engineering application like welded or adhesively bonded structures.{{Citation needed|date=September 2024}}

For example, some elements of Gothic cathedrals previously thought decorative were first proved essential for structural support by photoelastic methods.<ref>{{Cite news |last=Lewis |first=Michael |date=3 September 2024 |title=The Canary: Michael Lewis on Chris Mark of the Department of Labor |url=https://www.washingtonpost.com/opinions/interactive/2024/michael-lewis-chris-marks-the-canary-who-is-government/?itid=hp_latest-headlines_p001_f015 |work=[[The Washington Post]]}}</ref>