. "P\u0159\u00EDsp\u011Bvek k\u00A0teorii neline\u00E1rn\u00ED viskoelasticity je zalo\u017Een na d\u016Fsledn\u00E9 aplikaci volnoobjemov\u00E9 koncepce, v n\u00ED\u017E je krom\u011B tepeln\u00E9 dilatace voln\u00E9ho objemu uva\u017Eov\u00E1na i dilatace indukovan\u00E1 tahovou deformac\u00ED. Pokud je rostouc\u00ED voln\u00FD objem korigov\u00E1n pomoc\u00ED posuvn\u00E9"@cs . . "Neline\u00E1rn\u00ED viskoelasticita popisuje vratn\u00E9 deformace mezi limitou linearity nap\u011Bt\u00ED-deformace (n\u011Bkolik desetin % pro termoplasty) a bud' (i) deformac\u00ED na mezi kluzu nebo (ii) deformac\u00ED p\u0159i p\u0159etr\u017Een\u00ED (pro k\u0159ehk\u00E9 materi\u00E1ly). Neline\u00E1rn\u00ED chov\u00E1n\u00ED, kter\u00E9 je charakterizov\u00E1no r\u016Fstem poddajnosti s deformac\u00ED, neplatnost\u00ED superpozi\u010Dn\u00EDch princip\u016F a pomal\u00FDm zotaven\u00EDm, je pro aplikace mnohem d\u016Fle\u017Eit\u011Bj\u0161\u00ED ne\u017E line\u00E1rn\u00ED chov\u00E1n\u00ED. Rozm\u011Brov\u00E1 stabilita uva\u017Eovan\u00E1 v r\u00E1mci vratn\u00FDch deformac\u00ED mus\u00ED b\u00FDt nevyhnuteln\u011B popisov\u00E1na vterm\u00EDnech neline\u00E1rn\u00ED viskoelasticity. Jeliko\u017E termoplasty jsou \u010Dasto vystaveny dlouhodob\u011B p\u016Fsob\u00EDc\u00EDmu zat\u00ED\u017Een\u00ED, je jejich rozm\u011Brov\u00E1 stabilita p\u0159ednostn\u011B hodnocena podle odolnosti v\u016F\u010Di creepu a podle pr\u016Fb\u011Bhu zotaven\u00ED. Nam\u00EDsto obvykl\u00E9ho fenomenologick\u00E9ho popisu neline\u00E1rn\u00EDch viskoelastick\u00FDch vlastnost\u00ED je n\u00E1\u0161 alternativn\u00ED p\u0159\u00EDstup zalo\u017Een na (i) specifikaci p\u0159\u00ED\u010Din nelinearity, nap\u0159. deforma\u010Dn\u011B indukovan\u00FD voln\u00FD objem, existence prahov\u00E9ho nap\u011Bt\u00ED, neline\u00E1rn\u00ED vliv nap\u011Bt\u00ED na molekul\u00E1rn\u00ED pohyblivost, (ii)" . "5"^^ . "Neuvedeno."@en . "GA106/04/1051" . "5"^^ . . "Neline\u00E1rn\u00ED viskoelasticita a rozm\u011Brov\u00E1 stabilita termoplast\u016F a jejich sm\u011Bs\u00ED" . . "Nonlinear viscoelasticity describes reversible (recoverable) deformations between the stress-strain linearity limit (a few tenths of % for thermoplastics) and either (i) the yield strain or (ii) the strain at break (for brittle materials). Nonlinear behavior, which is characterized by the compliance rising with strain, invalidity of the superposition principles and slow strain recovery, is much more important for applications than linear behavior. The dimensional stability considered in the framework of recoverable deformations has to be inevitably treated in the terms of nonlinear viscoelasticity. As thermoplastics are often exposed to long-lasting loads, their dimensional stability is preferably evaluated according to their creep resistance and recovery. Instead of ordinary phenomenological description of nonlinear viscoelastic properties, our alternative approach will (i) specify the origins of nonlinearity, e.g. strain-induced free volume, existence of a stress threshold,"@en . . . "The contribution to the theory of nonlinear viscoelasticity is based on consistent application of the free volume concept considering the strain-induced dilatation in addition to the thermal dilatation. If the rising free volume is corrected by means of"@en . . . "1"^^ . . "2007-10-16+02:00"^^ . . "http://www.isvav.cz/projectDetail.do?rowId=GA106/04/1051"^^ . "0"^^ . "Nonlinear viscoelasticity and dimensional stability of thermoplastics and their blends"@en . . "0"^^ . . . . . . . . . .