"Materi\u00E1lov\u00E9 vztahy p\u0159i velk\u00FDch p\u0159etvo\u0159en\u00EDch se zam\u011B\u0159en\u00EDm na probl\u00E9my \u0161\u00ED\u0159en\u00ED nap\u011B\u0165ov\u00FDch vln a jejich aplikace v NDT"@cs . "393"^^ . . "1"^^ . . "One of the modern non-destructive methods for detecting residual stresses in materials is based on the dependence of propagating wave velocity on stress. This dependence is a result of the nonlinear interaction of the propagating wave with the pre-stressed continuum. The commonly used material model is based on the description of deformation by means of the Green-Lagrange strain tensor and the strain energy function in the form of a third-order polynomial. However, material parameters of this model are strongly unstable. In the presented project a new material model is proposed, in which the GL description is replaced with the logarithmic strain tensor. According to the previous research higher stability of material parameters is expected. The expressions for the velocities of acoustic waves in elastic material will be derived for the pre-stressed material by subjecting it to the hydrostatic pressure as well as to the uniaxial stress in the longitudinal and transverse directions with"@en . "Material response under finite strains aiming at problems of stress wave propagation and its applications in NDT"@en . . . . "Jedna z modern\u00EDch nedestruktivn\u00EDch metod zji\u0161\u0165ov\u00E1n\u00ED zbytkov\u00FDch pnut\u00ED v materi\u00E1lu je zalo\u017Eena na z\u00E1vislosti rychlosti \u0161\u00ED\u0159en\u00ED akustick\u00FDch vln na nap\u011Bt\u00ED. Tato z\u00E1vislost je projevem neline\u00E1rn\u00ED interakce \u0161\u00ED\u0159\u00EDc\u00ED se vlny s p\u0159edepjat\u00FDm prost\u0159ed\u00EDm. Obvykle pou\u017E\u00EDvan\u00FD materi\u00E1lov\u00FD model je zalo\u017Een na popisu deformace pomoc\u00ED Greenova-Lagrangeova tenzoru (GL) p\u0159etvo\u0159en\u00ED a funkci deforma\u010Dn\u00ED energie ve tvaru polynomu t\u0159et\u00EDho stupn\u011B. Materi\u00E1lov\u00E9 parametry tohoto modelu jsou v\u0161ak velmi nestabiln\u00ED. V p\u0159edkl\u00E1dan\u00E9m projektu je navr\u017Een jin\u00FD materi\u00E1lov\u00FD model, ve kter\u00E9m se GL popis nahrazuje logaritmick\u00FDm tenzorem p\u0159etvo\u0159en\u00ED. Na z\u00E1klad\u011B dosud proveden\u00E9ho v\u00FDzkumu se o\u010Dek\u00E1v\u00E1 vy\u0161\u0161\u00ED stabilita materi\u00E1lov\u00FDch konstant. Budou odvozeny vztahy pro rychlost \u0161\u00ED\u0159en\u00ED akustick\u00FDch vln v elastick\u00E9m materi\u00E1lu p\u0159edepjat\u00E9m hydrostatick\u00FDm tlakem a d\u00E1le jednoos\u00FDm nap\u011Bt\u00EDm ve sm\u011Bru p\u0159\u00ED\u010Dn\u00E9m a pod\u00E9ln\u00E9m ke sm\u011Bru \u0161\u00ED\u0159en\u00ED vlny. Bude navr\u017Eena metoda pro identifikaci koeficient\u016F t\u0159et\u00EDho \u0159\u00E1du a ov\u011B\u0159ena na v\u00FDsledc\u00EDch ji\u017E proveden\u00FDch m\u011B\u0159en\u00ED. Nov\u00E1"@cs . "393"^^ . . . . . . . "Neuvedeno."@en . "0"^^ . "4"^^ . "0"^^ . "4"^^ .