Technologia i Automatyzacja Montażu (Assembly Techniques and Technologies)

Influence of the Temperature Changes on Stresses in Carbon Composite Fastening Bolts

2024-07-02T20:22:34+00:00

High joint strength of composite structures can be achieved by using mechanical fasteners. The materials used for rivets and bolts have lower coefficients of thermal expansion than composites in the direction perpendicular to the reinforcement fibers. It is suspected, therefore, that temperature changes can cause stress changes in mechanical fasteners. The purpose of this study was to experimentally determine and analytically substantiate the values of stress changes resulting from a change in temperature in the range from -20 to 60°C in M8 steel bolts fastening carbon composite. The value of stress changes was estimated to be around 100 MPa, which can consequently lead to joint unsealing or plastic deformation of the mechanical fastener.

Projectile seating depth influence on a small arms cartridge performance

2024-07-02T20:23:02+00:00

Abstract
In the world of small-arms ammunition, precision reigns supreme. The most significant feature of ammunition for shooters is undoubtedly the repeatability from one shot to the next. This study explores the detailed assembly process of small arms cartridges, leveraging modern machinery and innovative designs employed by cartridge manufacturers. It emphasizes how these tools ensure the fundamental repeatability and precision necessary for the quality of each batch of rounds. Establishing standards for the highest possible quality requires assessing the impact of imprecise cartridge assembly on ballistic performance.
Utilizing a free-flight ballistic tunnel, a high-speed camera, light- and target-screen systems, the authors analyzed the effects of varying projectile seating depths thus affecting cartridge overall lengths (COAL) and cartridge base to ogive distance (CBTO) on the initial velocity and bullets’ point of impact at 50 meters. The study was conducted for two types of projectiles, differing in their ogive profiles: secant and tangent ogive. The performance differences between these profiles provided valuable insights for future projectile designs, highlighting that low-drag projectiles are slightly more sensitive to the seating depth than tangent profile bullets, and the importance of it should be considered in mass, military production as well. It is a valuable resource for analyzing the trade-off between producing bullets with a low drag coefficient and ensuring high precision. The research enhances the understanding of internal and external ballistics but most importantly draws attention to the importance of the standards of assembly processes to ensure optimal performance and safety in the field.

Streszczenie
Zapewnienie powtarzalności między kolejnymi strzałami jest niewątpliwie najistotniejszą cechą nabojów dla każdego strzelca. Autorzy poddali analizie proces montażu nabojów do broni strzeleckiej, wykorzystujący nowoczesne maszyny i innowacyjne rozwiązania konstrukcyjne stosowane przez światowych producentów amunicji. Biorąc pod uwagę jakość wykonanej amunicji, te narzędzia są wykorzystywane do zapewnienia jak największej dokładności i powtarzalności, które są fundamentalne w kwestii kontroli jakości partii nabojów. W celu wypracowania odpowiedniego standardu zapewniającego wymaganą jakość amunicji, istotne jest oszacowanie wpływu nieprecyzyjnego montażu nabojów na ich charakterystyki balistyczne.
Przeprowadzając badania w tunelu balistycznym z wykorzystaniem kamery szybkiej oraz bramek prędkościowych i współrzędnościowych, przeanalizowano wpływ zmiennej głębokości osadzenia pocisku, a więc również całkowitej długości nabojów (COAL) oraz odległości od dna łuski do części ostrołukowej (CBTO) na prędkość wylotową i punkt trafienia pocisków na odległości 50 metrów. Analizy przeprowadzono dla różnych typów pocisków, różniących się kształtem części ostrołukowej. Wpływ różnic w ich konstrukcji na charakterystyki balistyczne jest istotny pod względem przyszłościowych nabojów, ponieważ pociski o mniejszym współczynniku oporu czołowego – większym promieniu profilu części ostrołukowej, są wrażliwsze na głębokość osadzenia, niż pociski o profilu ostrołuku stycznym do części cylindrycznej, które charakteryzują się większym współczynnikiem oporu czołowego. Analizowane różnice okazują się istotne również w masowej produkcji amunicji wojskowej. Wyniki stanowią cenne źródło informacji w poszukiwaniu kompromisu między produkcją pocisków o niskim współczynniku oporu aerodynamicznego, a zapewnieniem wysokiej precyzji. Praca pogłębia zrozumienie balistyki wewnętrznej i zewnętrznej, ale przede wszystkim zwraca uwagę na znaczenie jakości procesu montażu amunicji w kwestii zapewnienia optymalnej skuteczności zastosowania i bezpieczeństwa na polu walki.

Classification Graph of Poka-Yoke Techniques for Industrial Applications: Assembly Process Case Studies Effectiveness Evaluation

2024-07-02T20:23:28+00:00

It is widely acknowledged that the expenses associated with substandard quality constitute a significant portion of a company's overall costs. Consequently, organizations adopt quality management systems and implement corrective and preventive measures to reduce these expenses. Within these implementations, Poka-Yoke techniques are notably prominent. Theoretically, these techniques are designed to prevent mistakes that lead to costs, especially quality-related costs associated with nonconforming products. This study proposes a classification of Poka-Yoke techniques and a methodology for evaluating the effectiveness of these techniques. The methodology was applied in the evaluation of selected techniques implemented in various assembly tasks. This assessment relies on objective characteristics of the techniques. The value of this method lies in its ability to easily evaluate techniques to implement in areas where interventions are needed to increase the reliability of the production system. Thus, it serves as a simple tool to help design new and improve existing workplace organizations.

Compact VOC emission test chamber

2024-07-02T20:23:58+00:00

The publication presents the test method and construction of a compact VOC emission test chamber. Volatile organic compounds (VOCs) are mainly occur in paint and construction materials containing chemical resins, bitumen, binders, adhesives, etc., as well as residues of unreacted monomers. VOC emission testing is carried out on product samples in environmental chambers in accordance with PN-EN ISO 16000-9. The developed chamber, together with a proprietary control and test parameter acquisition system, allows testing at a stabilized temperature and humidity of air washing over the sample at a specified rate. Qualitative identification and quantitative testing of compounds present in the air inside chambers is carried out using a chromatograph, and the test results are compared with regulations on permissible chemical pollutants in the air of buildings and in atmospheric air. The developed chamber with horizontal sample loading is another version of VOC chambers, developed in response to market demands, offered and implemented in research laboratories by the Łukasiewicz Institute for Sustainable Technologies in Radom.

The impact of the degree of automation on the configuration of a car battery assembly line

2024-07-02T20:24:18+00:00

This paper presents the concept of an automotive battery assembly line. The line includes in its structure fully and semi-automated assembly sockets, as well as manual assembly sockets. The transport between the sockets is carried out using an AGV autonomous trolley system. The selection of the assembly process execution method was based on an analysis of the technical feasibility of the process as well as an analysis of the occupation time of individual assembly stations. The resulting line structure indicates to what extent the automation of the assembly process contributes to a change in material flow and influences the way the process is carried out, including a variety of technical means used. The paper presents an analysis of the use of particular workstations. This analysis was used to optimise the flow of the component assembly line. Maximum utilisation of the resources involved in the production process was used as a criterion for optimisation.

Using drones and artificial intelligence to assess damage in aircraft assembly joints

2024-07-02T20:24:41+00:00

Rapid development of Artificial Intelligence (AI) technologies in recent years has created new opportunities to address the growing challenges in the aviation industry. Machine learning and Deep Learning, particularly through Convolutional Neural Networks (CNNs), have advanced image recognition capabilities, enhancing inspection processes possibilities. This paper explores the integration of AI with drones to improve the precision, efficiency, and speed of inspections of airframe emphasizing the necessity of accurate equipment preparation and precise operational planning. The study demonstrates how AI algorithms can process high-resolution images and sensor data to identify and classify defects. The motivation for this paper is to address the critical need for more efficient inspection methods in aviation, driven by the industry's increasing demand for higher repair process throughput and stringent safety standards.