The paper presents an analysis of mixed-mode fatigue crack growth in bridge steel after 100-years operating time. Experiments were carried out under mode I + II configuration on Compact Tension Shear (CTS) specimens and mode I + III on rectangular specimens with lateral stress concentrator under bending and torsion loading type. Due to the lack of accurate Stress Intensity Factor (SIF) solutions, the crack path was modelled with the finite element method according to its experimental observation. As a result, the Kinetic Fatigue Fracture Diagrams (KFFD) were constructed. Due to the change in the tendency of higher fatigue crack growth rates from K_I towards K_III dominance for the samples subjected to bending and torsion, it was decided to analyze this phenomenon in detail using electron-scanning microscopy. The fractographic analysis was carried out for specimens subjected to I + III crack loading mode. The mechanism of crack growth in old bridge steel at complex loads was determined and analyzed.

The present study examines the separate and synergistic effects of macroalgal extract and static magnetic field (SMF) on the germination of soybean seeds (Glycine max (L.) Merrill), cv. Abelina, seedling growth, chlorophyll, and carotenoids content in leaves. Algal extract was produced from freshwater green macroalga (Cladophora glomerata) using ultrasound-assisted extraction. The germination tests were conducted in two stages. Firstly, different concentrations of extracts, 20%, 40%, 60%, 80%, and 100%, were applied to a paper substrate. The best results (taking into account germination percentage, seedlings length and weight, and pigments content in leaves) were observed for 20% and 80% extracts. At the same stage, germination of seeds exposed to SMF (exposure times for 3 and 12 min and magnetic inductions of 250 and 500 mT) was studied. The best developed seedlings were determined for the group treated at 3 min with a magnetic induction of 250 mT. In the final step, the simultaneous effects of 20% and 80% algal extracts and treatment with 3 min at 250 mT SMF were tested. Taking into account all the parameters, the simultaneous use of 20% extract and 3 min of 250 mT magnetic induction is recommended.

The paper presents a comparison of the results of the fatigue crack growth rate for raw rail steel, steel reinforced with composite material—CFRP—and also in the case of counteracting crack growth using the stop-hole technique, as well as with an application of an “anti-crack growth fluid”. All specimens were tested using constant load amplitude methods with a maximum loading of Fmax = 8 kN and stress ratio R = σmin/σmax = 0.1 in order to analyze the efficiency of different strategies of fatigue crack growth rate deceleration. It has been shown that the fatigue crack grows fastest in the case of the raw material and slowest in the case of “anti-crack growth fluid” application. Additionally, the study on fatigue fracture surfaces using light and scanning electron (SEM) microscopy to analyze the crack growth mechanism was carried out. As a result of fluid activity, the fatigue crack closure occurred and significantly decreased crack driving force and finally resulted in fatigue crack growth decrease.

In this paper the investigations of magnetostriction as well as DC magnetic properties for composites doped with Terfenol-D particles are presented. All investigations were performed for the materials with 35%, 46% and 70% volume fraction of the Terfenol-D particles surrounded by epoxy matrix. Moreover, the bulk Terfenol-D alloy was tested. The obtained results show that the magnetization of the composite materials increases with increasing the volume fraction of Terfenol-D particles. Similar dependence as for magnetization was observed for the magnetostriction measurements. Although the magnetostriction of composite material is smaller than for solid Terfenol-D it is still tens of times bigger than in case of traditional magnetostrictive materials. Obtained results gives opportunity to use these materials for variety applications such as actuators and sensors.