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This paper concerns the numerical simulations, by a commercial FEM code, related to notched specimens experimentally tested by neutron diffraction and synchrotron radiation diffraction, in order to correlate the deformation states around the crack tip. Two cracked specimens were analyzed. In one case a long crack has been induced into the specimen, which has been investigated subsequently by neutron diffraction technique. In the other case a smaller crack was induced, which has been investigated by synchrotron radiation diffraction technique. The numerical and experimental results are substantially in good agreement. However some differences can be observed; the reason can be found in the microscopic structure and particular history of the material under load. [ABSTRACT FROM AUTHOR]

Fatigue crack growth experimental tests and numerical analyses on Friction Stir Welding (FSW) welded flat stiffened panels were performed in order to assess their fracture resistance capability. Panels and stiffeners are made of aluminum alloy 2024-T3. Linear elastic FEM (Finite Element Method) and DBEM (Dual Boundary Element Method) stress analyses were performed to simulatecrack growth, obtaininga satisfactory correlation againstexperimental outcomes. [ABSTRACT FROM AUTHOR]

• risk analysis of climate-induced fatigue on wooden surfaces inside six rural Swedish churches. • Past monitoring campaigns used for gathering info about number/entity of thermal fluctuations. • Investigated constant- and variable-amplitude climate-induced fatigue behaviors. ○ Assessed possible damage accumulation caused by repeated thermal fluctuations over time. ○ Compared results with surface decay level from in-situ conservation surveys. Environmental variations of Temperature (T) and Relative Humidity (RH) in air cause a superficial and/or sub-surface deformation (shrinkage/swelling) of organic hygroscopic objects, as for example wood. These environmental variations may be due to the natural variability of climate, to the use of Heating, Ventilation and Air Conditioning (HVAC) systems and to the presence of people. This contribution focuses on a group of wooden rural churches located in harsh climates in Sweden. The churches, which are still in use for the local communities, are heated during wintertime to reach acceptable indoor comfort levels causing potentially risky T and RH fluctuations for hygroscopic objects. In this framework, the main goal is assessing the risk of fracture on wooden structural elements caused by hygrothermal fluctuations. The method is based on a preliminary approach for reconstructing the climate history experienced by a typical wooden structural element of these churches and that, over time, results in a cyclic fatigue loading, naturally induced by the outdoor climate. Then, the effect of the artificial heating on the indoor microclimate and, therefore, on the reconstructed fatigue curve is assessed. Main outcomes were obtained by using a methodology that is preliminary based on simplifying assumptions, due to a severe lack of knowledge, in literature, about the fatigue behavior of wood. Finally, main considerations on the fatigue behavior of exposed wooden elements are drawn up, namely the estimation of their residual life (or "life-to-damage"), which may support conservators or church managers in better managing the microclimate to reduce the risk of fracture on valuable objects. [ABSTRACT FROM AUTHOR]

• Exploring post-processing treatments to improve fatigue resistance of LPBF Ti6Al4V. • High pressure heat treatment produced isotropic α + β macrostructure. • Dry electropolishing and sandblasting reduced inherent surface irregularities. • Tensile properties comparable to forged Ti6Al4V used in automotive field. • Fatigue performance is increased with tailored post-processing treatments sequence. This study investigates the impact of post-processing techniques on the fatigue behaviour of specimens in Ti6Al4V made by laser powder bed fusion (LPBF) for relevant applications, such as motorsport. Despite the LPBF advantages in terms of complex design and weight reduction, challenges such as reduced fatigue performance persist. Therefore, the application of post-processing treatments can play a critical role. In addition to traditional sandblasting (SB), three post-processing conditions were investigated to enhance mechanical properties under quasi-static and fatigue loading conditions: heat treatment (HT) and the innovative High Pressure Heat Treatment (HPHT) along with dry electropolishing (EP) treatment. The results indicate that both the HT and HPHT treatments produced a macrostructure with equiaxial grains composed of fine α + β lamellae. Mechanical analyses demonstrated that the HPHT-SB-EP condition exhibits properties comparable to those of forged Ti6Al4V used in the automotive field, with a good balance between strength and ductility. The EP treatment effectively reduced surface roughness and inherent surface irregularities caused by the LPBF process. The best fatigue results were achieved with the HPHT-SB-EP condition, despite data scattering. An increase in fatigue resistance was observed by using SB at a higher pressure. [ABSTRACT FROM AUTHOR]