As part of an evaluation to determinate the influence of the stress gradient on the stress-life response of a given component, a series of double-notched samples was tested uniaxial stress-controlled fatigue tests. Its results were then compared with the results of similar tests made using single notch specimens. Although the inherent geometrical differences between the sample series, the stress concentration factors are in the range of 2.5 ± 10 % for all series. Nevertheless, the experimental results have shown a very different fatigue response of the double- notched series. To explain the aforementioned behavior, the authors have employed numerical simulation and a non-linear regression function to generate adjusted stress-life curves. The investigation shows, that is not enough to consider the stress concentration factor as main governing parameter, but also the stress gradient and the fatigue notch factor should be taken into account in order to narrow down non- conservative calculations when estimating lifetime.

This paper outlines two examples of application of close-range photogrammetry, their preliminary results and observations. The first application is identification and measurement of deformations and displacements of the vehicle chassis after a frontal crash-test. This is done by comparison between the pre- and post-crash models and measurements. The second mentioned application is determination of the road pavement macro-texture, where the photogrammetry can serve as an alternative method.

Unlike most metallic materials, some synthetic materials are known to exhibit a very prominent creep behavior. Additionally, among many other variables, this type of effect is highly dependent on the material temperature. The aim of this work is to study the creep behavior of synthetic ropes used in the anchorage of offshore platforms working in deep and ultra-deepwater. In these regions the low temperature of the water affects directly the behavior of the synthetic materials when subjected to permanent tensile loads. These results are shown in a displacement-time graph, in which the three creep phases are identified by the slope of each curve. The creep test is characterized by the application of a static load with the purpose to observe the deformation of the synthetic material over time. The loadings applied in this paper are relative to 5%, 20% and 45% MBL (medium break load of the material). To perform such test, this paper details the project of an equipment in which the specimens will be positioned vertically and submerged into water at 4 °C ± 1 K. The load will then be applied in a lever-type mechanism. This type of system is relatively simple and requests a minimum friction between its mechanical components. The data are recorded by a digital system during the test time.

The paper describes validation of selected multiaxial fatigue criteria in the region of limited lifetime. Used test data and methodology of validation are described. Results of validation are presented.

Current research is aimed to create functional material models out of test data to use them in numerical simulations. This process contains several material tests such as tensile tests and dynamic mechanical analyses at different temperatures. All determined test results were used as input data to process model parameters. The selected material models are the hyperelastic Odgen-model, the viscoelastic Prony-series and the hyper-viscoelastic Bergström-Boyce model. After the implementation in ABAQUS/CAE, a comparison of real tensile test data and simulated tensile tests under the same circumstances was developed to ensure the correctness of the models. Finally, a Diabolo specimen was modeled and loaded in the same way as in real-life fatigue tests under tensile loading. This simulation provides information about the stress-strain behavior of the specimen and is meant to build calibration curves which are used for strain-based Wöhler curves later on.