Es wird ein einfacher Berechnungsansatz für ein Baukastensystem aus Kastenprofilen verschiedener Querschnittsabmessungen erarbeitet. Diese Profile bestehen aus WVC (Wood Veneer Composites, Holzfurnierlagenverbundwerkstoffen). Der Ansatz bildet den statischen Lastfall und das Ermüdungsverhalten unter schwellende Dreipunktbiegung ab. Am Beispiel eines ausgewählten Strukturbauteils aus handelsüblichen Birkensperrholz wird der Berechnungsansatz konkretisiert und durch Versuche evaluiert. Aufbauend auf dem Kraft-Verformungsverhalten der analysierten Einzelbauteile und der kapillarporösen Struktur des Holzes wird bei dem Berechnungsansatz auf eine Analyse der Spannungen verzichtet. Stattdessen wird als Berechnungskriterium die kritische Normaldehnung in der Randfaser der Strukturbauteile genutzt. Weiterhin wird eine Methode vorgestellt um mittels niederzyklischen Ermüdungsversuchs (LCF, ca. 1e+03 Lastwechsel) den „Knickpunkt“ der Zeitfestigkeitslinie eines einstufigen Ermüdungsversuchs bei hohen Lastspielzahlen (HCF, 1e+06 bis 1e+07 Lastwechsel) für diese Strukturbauteile zu bestimmen. / It was developed a simple approach for the calculation of a modular construction system for box sections (profile structures) of different cross-sectional dimensions. These profile structures consists of WVC (Wood Veneer Composites). The approach maps the static load case and the fatigue behavior under pulsating three-point bending. By using a structural component made from commercial birch plywood, the calculation approach is specified and verified. Based on the force-deformation behavior of the analyzed single components in connection with the capillary-porous structure of the wood, the calculation approach dispense on an analysis of the tensions. Instead, a criterion, which calculates the critical normal strain in the outer fibers of the structural components, is used. Furthermore, a method of a low-cycle fatigue test (LCF, abbr. 1e+03 cycles) is presented. This method detects the “knee point" of the fatigue limit line for the profiles. That point is usually determined by the use of a high-cycle fatigue tests (HCF, 1e+06 until 1e+07 cycles).

Pseudoelastic NiTi shape memory alloys exhibit different stress–strain curves and modes of deformation in tension vs. compression. We have recently shown that under a combination of compression and shear, heterogeneous deformation can occur. In the present study, we use digital image correlation to systematically analyze how characteristic features of the nominally uniaxial engineering stress–strain curves (particularly the martensite nucleation peak and the plateau length) are affected by extensometer parameters in tension, compression, and the novel load case of shear-compression. By post-experimental analysis of full surface strain field data, the effect of the placement of various virtual extensometers at different locations (with respect to the nucleation site of martensite bands or inhomogeneously deforming regions) and with different gauge lengths is documented. By positioning an extensometer directly on the region corresponding to the nucleating martensite band, we, for the first time, directly record the strain-softening nature of the material—a specific softening behavior that is, for instance, important for the modeling community. Our results show that the stress–strain curves, which are often used as a basis for constitutive modeling, are affected considerably by the choice of extensometer, particularly under tensile loading, that leads to a distinct mode of localized deformation/transformation. Under compression-shear loading, inhomogeneous deformation (without lateral growth of martensite bands) is observed. The effects of extensometer gauge length are thus less pronounced than in tension, yet systematic—they are rationalized by considering the relative impact of differently deforming regions.

This thesis deals with problems of biomechanics of soft tissues, namely of stress-strain analysis of abdominal aortic aneurysm (AAA). The introduction describes briefly the possibility of aneurysm occurrence with a focus on an aneurysm in the abdominal aorta.

Presented work deals with Biomechanical study of the facial skeleton. This work is focused on the fixation of the mandible after removal of a tumor from affected bone tissue. The aim of the work is to perform biomechanical study of the facial skeleton with subsequent detailed stress strain analysis of two mandible implants designed and manufactured for specific patients. The geometry model of mandible used for design of mandible implants and used for computational modelling has been obtained on the basis of CT data of two patients. A Theoretical-Clinical sub-study that deals with the comparison the CT data processing which is necessary for creating the model of geometry is a part of the thesis. Two models of mandible with applied mandible implant have been created for two specific patients with tumorous mandible bone tissue. Stress strain analysis has been performed for these two models. Results of the stress strain analysis of two models of mandibles with mandible implants are presented in the final chapters of the thesis. Findings of the biomechanical study have been published and applied in clinical practice.

Presented work deals with Biomechanical study of the facial skeleton. This work is focused on the fixation of the mandible after removal of a tumor from affected bone tissue. The aim of the work is to perform biomechanical study of the facial skeleton with subsequent detailed stress strain analysis of two mandible implants designed and manufactured for specific patients. The geometry model of mandible used for design of mandible implants and used for computational modelling has been obtained on the basis of CT data of two patients. A Theoretical-Clinical sub-study that deals with the comparison the CT data processing which is necessary for creating the model of geometry is a part of the thesis. Two models of mandible with applied mandible implant have been created for two specific patients with tumorous mandible bone tissue. Stress strain analysis has been performed for these two models. Results of the stress strain analysis of two models of mandibles with mandible implants are presented in the final chapters of the thesis. Findings of the biomechanical study have been published and applied in clinical practice.