Technologia i Automatyzacja Montażu (Assembly Techniques and Technologies)

Strength tests of repair joints loaded with tension and loss of stability

Iga Barca — 2024-12-27

During aircraft service, the skin is the component that first comes into contact with factors that can cause mechanical damage - that is why it is most often damaged during use. Semi-monocoque aircraft structures are made of a skin (usually aluminum alloy) and a frame. The skin is an element that significantly affects the safety of the structure, since it transfers loads between the elements of the frame. For this reason, the skin is subject to special supervision during technical maintenance, and any damage detected must be repaired. The research was carried out on specimens made of AW 2024-T3 plate sheet with a thickness of 1 mm. In the study, a comparative analysis of damaged, undamaged and repaired specimens loaded in tension and compression was performed. Different patches were used in repaired specimens, made of metallic as well as composite materials, connected to the structure with rivets or using adhesive materials. The study showed that the use of riveted as well as adhesively bonded overlays does not allow the original strength of the tensile-loaded skin to be restored, but does allow the strength of the compression-loaded skin to be restored (loss of stability). In addition, numerical simulations were performed to define the stress field occurring in the adhesive joint for different geometric dimensions of the plate (thickness, width). The results of the numerical analysis showed that the geometry of the plate model influences the values of reduced stresses in the adhesive weld and the patch. Regardless of the analyzed changes in the geometry of the plate model, the maximum values of reduced stresses are similar to each other. The smallest values of reduced stresses in the adhesive joint and composite patch were obtained for the case of a plate with a thickness of 1 mm and a width of 160 mm.

E-learning, VR and techno-educational stands as a way for practical optimalisation of education for the automation needs

Andrzej Stępnikowski — 2024-12-27

The publication presents a hybrid learning approach for training in the field of automation, focused on Programmable Logic Controllers and teacher-trainer relation in the VR. In this case hybrid learning is a mix of such methods like: physical techno-educational stands (possible to be used also for distant learning), e-learning courses and Virtual Reality Learning Environment (VRLE). In this article we will present two such VRLE that can be used through web browsers 2D and/or fully immersive experience in VR. To some extent we will present here also results of our initial research on the use of VR in this context. This article gives an insight on the ways how to embed such interactive environment with traditional forms like work-based learning, simulations and e-learning courses. Such “blended” education helps to develop learning management system through the Protocol of Learning Technologies Integration (PLTI). This contribution presents results of studies conducted during hybrid workshops in Poland and Lithuania. Results show that blended learning approach can give greater motivation and satisfaction to a learner thanks to multi-modal learning environment (MMLE), moreover there are some indications that it could also enrich learning retency. This MMLE was developed in response to market demands (pilot), offered and implemented in research laboratories by the Ruhr University in Bochum (Germany) and Łukasiewicz Institute for Sustainable Technologies in Radom (Poland). Such actions are aligned with the newly adopted EU strategy to lead Web 4.0 and virtual worlds.

The Influence of aging on the load capacity of adhesive lap joints made of aluminum alloy EN AW-2024-T3

Ewelina Ozga — 2024-12-27

The aim of the study was to assess the effect of environmental ageing on the load capacity of single-lap adhesive joints made of EN AW-2024-T3 aluminum alloy, subjected to and not subjected to pneumatic shot peening. Adhesive joints were made using two-component epoxy adhesive Loctite EA 3430. Half of the formed joints were strengthened by pneumatic shot peening of the overlap zone. The shot peening time was 120 s, the ball diameter was 1.0 mm, and the compressed air pressure was 0.5 MPa. The adhesive joints were then subjected to different variants of ageing in natural conditions. Individual variants differed in the length of ageing. The next step was to examine the load capacity of the adhesive joints using a static tensile test. The results were subjected to statistical analyzes, including analysis of variance (ANOVA), regression and correlation analysis, and Student's t test. Based on the analyzes, it was found that for the assumed range of input factor variability, ageing of joints not subjected to shot peening increased their load capacity by 38%. Aging of joints strengthened by shot peening resulted in a 62% decrease in their load capacity. The ageing length had a significant effect on the load capacity of the adhesive joints.

Analysis of the possibilities of implementing alternative methods of joining semifinished products in the production process of steel rims

Izabela Miturska-Barańska — 2024-12-27

Assembly technology plays a crucial role in the manufacturing process, influencing the efficiency, quality, cost and lead time of production. Assembly technology in the manufacturing process encompasses all techniques and methods used to join components into a finished product. Depending on the industry and specific requirements, assembly technologies can include a variety of techniques, from traditional mechanical joints to advanced bonding, welding or soldering methods. The paper analysed the feasibility of implementing alternative methods of joining blanks in the steel wheel manufacturing process. Testing was carried out to replace the wheel rim flash welding process with laser welding. The effectiveness of laser welding was evaluated by testing prepared butt jointed sheet samples. Tests were carried out on two types of structural steel: S355MC and DD11, which were subjected to flash welding and laser welding. The specimens were subjected to strength and macrographic tests to analyse their structure and mechanical properties. The results showed that laser welding for DD11 steel leads to an increase in tensile strength, while for S355MC steel this strength is reduced. Statistical analysis showed no significant differences between the assembly methods used and the steel types. Macrographic tests confirmed the presence of oxides and other characteristics of the assembly methods used. The results suggest that the choice of the appropriate joining method can have a significant impact on the quality and durability of the final product, which is crucial in the context of steel wheel production

Surface topography creation of machine elements after carburizing process with application of burnishing method

Lidia Gałda — 2024-12-27

Various types of bushings or pins are widely used in the machinery industry, i.e. in the automotive industry, agricultural machinery and production lines. Such machine components operate in a diverse environment, not infrequently in polluted or dusty environments and these components may be subjected to intensive wear. Particles circulating in various types of machine kinematic pairs contribute to accelerated or even emergency wear of the equipment. One way to prevent such dangerous failures is to use an additional machining to create dimples in the surface, which are a place to collect lubricant but also abrasive particles. The article presents a method of burnishing a cylindrical surface after carburizing treatment and after hardening, after which the hardness of the surface layer was about 60 HRC. As a result of using appropriate tools, it was possible to create regular and reproducible dimples in the surface. A surface topography parameter was also proposed, which makes it possible to evaluate the increase in oil capacity of the created cavities quickly and with high quality standards.

Voice control system for collaborative robot used in assembly process

Jan Czyżewski — 2024-12-27

This work is devoted to the issue of recognizing voice commands by the voice control system of a collaborative robot in an industrial environment. Such a robot will be designed to cooperate with a human during the assembly process. This method of communication significantly facilitates and speeds up work, increasing the efficiency of the assembly process and reducing the operator's workload. However, production halls and other places where assembly takes place are environments filled with sounds with a wide spectrum of intensity and frequency. Such an environment significantly impedes the functioning of the voice control system. This work examined the impact of sound pollution on the robot's command recognition.