IDENTIFICATION OF MATERIAL PROPERTIES OF COMPOSITE MATERIALS

摘要

Straipsnyje apra?omas kompozitini? med?iag? tamprumo charakteristik? identifikavimo metodas naudojant bandini? vibracinius bandymus, genetinius algoritmus, baigtini? element? metod? ir bandini? formos optimizavim?. Identifikavimo metu tamprumo charakteristikos skaitmeniniame modelyje yra atnaujinamos tol, kol skaitinio eksperimento rezultatai nustatytu tikslumu sutampa su vibracinio bandymo rezultatais. ?io straipsnio pagrindinis u?davinys yra padidinti Puasono koeficiento identifikavimo tikslum?, kadangi ?is, palyginti su kit? tamprumo charakteristik? identifikavimo tikslumais, yra menkas d?l ypa? ma?os koeficiento ?takos bandinio tikriniams da?niams. Darbe parodyta, kad ?manoma padidinti Puasono koeficiento ?tak? optimizavimo procedūromis, pasirenkant konkre?ias bandinio savybes (kra?tini? proporcijas, ortotropijos kamp? ir t.t.). Pateikiami keleto stiklo ir anglies pluo?tais armuot? kompozitini? med?iag? tamprumo charakteristik? identifikavimo rezultatai.%Present paper describes the facilities of composite material properties identification technique using specimen vibration tests, genetic algorithms, finite elements analysis and specimen shape optimization. In identification process the elastic constants in a numerical model is updated so that the output from the numerical code fits the results from vibration testing. Main problem analysed in this paper is that Poisson's ratio is the worst determined elastic characteristic due to its low influence on specimen eigenfrequencies. It is shown that it is possible to increase its influence by choosing specific test specimen characteristics (side aspect ratio, orthotropy angle, etc.) via optimization routine. In this paper are presented test results of some experiments wherein glass-epoxy and carbon-epoxy material properties were identified.