The study presents an analysis of S355J2+N steel and AA5083 aluminum alloy welded structural joints using explosion welded transition joints of reduced thickness. The transition joint thickness reduction significantly hinders the welding of the joints due to the risk of damage to the Al/steel interface as a result of the high temperatures during welding. In the previous article, the strength of the transition joint was analyzed but ship structures, apart from static loads, are subjected to many different cyclical loads. Welded structural joints are analyzed to determine the welding influence on the fatigue life and fracture type of the transition joints. The results of the fatigue tests show that the fatigue damage in the specimens occurs in the aluminum welded joint, and not in the explosively welded joint. The damage obtained was characteristic of cruciform welded joint specimens and both types of root and toe damage occurred. Based on the obtained results, fatigue curves for the joint were determined and compared to the fatigue curves for the AA5083 base material. The experimental fatigue curve was also compared with the design curve for welded aluminum structures from Eurocode. The conducted analysis showed the possibility of using Al/steel explosion welded transition joints of reduced thickness to transfer cyclical loads.

Structural adhesives are increasingly used in the construction of mechanical devices. Adhesive joints replace welded, soldered and other joints. The strength of the adhesive joints obtained allows the transfer of loads. The possibility of combining different materials is a significant advantage. In order to design joints, it is necessary to know the mechanical properties of adhesives. Determining them requires the use of special methods of obtaining specimens. Analytical and numerical methods of stress estimation in adhesive joints require more material data than is provided by manufacturers. The aim of the following work is to present the method of manufacturing specimens and to compare methods for determining mechanical properties based on three example structural adhesives. The paper presents two methods for determining the mechanical properties of exemplary structural adhesives: metacryl, epoxy and polyurethane adhesive. The tests were carried out on a cast and then machined specimens. Flat specimens were used in a tensile test. In compression test, round specimens were used. The results obtained from both tests were compared with the manufacturer's data. Differences and possible reasons for them were indicated. Stress distributions in the adhesive single lap joint were estimated using the Volkersen analytical method for various determined mechanical properties.

This study presents the testing results of methacrylic adhesive single-lap joints made from elements with different stiffness and of the adhesive itself, using cast specimens. Methods for the preparation and testing of material specimens of the adhesive joints have been presented. Moreover, an attempt was undertaken to determine the strength criterion and find out which of the presented calculation methods enables the most precise assessment of strength in the tested group of single-lap joints, that differ in terms of the adhered stiffness and thickness. For this purpose, C45 steel and 5754 aluminium flat bars were bonded. Stress distributions were determined for failure forces obtained in the experiment by means of three basic analytic and numerical methods. Stress and strain states were compared, indicating the highest consistency for the value of normal peel stresses acting in the direction perpendicular to the direction of the joint tension. Reduced stresses provided by the analyses reached values higher than those which were achieved during the specimen tension testing.

This study presents the results of tests involving determining quantities used to describe fracture toughness of a heat-treated AA2519 aluminum alloy applied in, among other things, constructing American military amphibians. These quantities were determined using the J–R curve method for two temperature values, 293 K and 77 K. The low temperature was provided by putting the tested specimen into a liquid nitrogen bath and keeping it there throughout the experiment. Based on the tests results, cryogenic conditions cause an increase in the maximum experimental value of the J–J_Q integral, from 66.3 to 87.3 kJ/m² Moreover, an analysis of the fatigue fracture microstructure revealed differences between specimens tested in ambient temperature and those tested in cryogenic temperature.

The article presents the results of an analysis of the crack growth and fatigue life of CT specimens made of explosively welded AA2519–AA1050–Ti6Al4V layered material for the construction of air and space structures. The investigations were carried out for two temperature conditions: ambient temperature (293 K) and under cryogenic conditions at the temperature of liquid nitrogen (77 K). The analysis of the test results revealed the impact of cryogenic conditions on the process of fatigue cracking of a layered material. However, this impact is partly limited by a significant scatter of the test results, which may be caused by the different character of the process of cracking.