G-Force Test Stand for the Evaluation of Weapon Component Strength

This paper discusses the design of a G-force test stand intended to examine of the effects of mechanical loads present during firing of a weapon and applied to the electronic components contained in the 155 mm calibre guided projectile. The G-force test stand is used to develop and test the effects of using high mechanical loads by decelerating a test specimen through the use of a purpose-designed fender assembly. For the purpose of testing, it is irrelevant whether a load is developed by acceleration or deceleration of the test specimen, as a test result obtained by the deceleration of a test specimen is equivalent to a test result obtained by the acceleration of a test specimen, as used in a 155 mm calibre artillery guided projectile. The G-force test stand was used to test and determine the velocities developed by the test specimens and the G-forces applied to them. The maximum velocity to which a test specimen was accelerated was approx. 72 m/s. The test stand was able to propel the test specimens to velocities an order of magnitude higher than the velocities obtained with a Kast and Masset ram. The tests were performed with rubber and copper fender assemblies. The effect of the specific fender used was demonstrated on the trend of the generated G-force. The test stand could develop G-forces in excess of 10,000 with a duration of more than 500 µs.

Design and Test of Load-Lifting Performance for Hydraulic Linkage of the High-Medium Horsepower Tractor

To improve the detection efficiency and safety of the tractor, the research proposed a device for detecting the loading–lifting performance of the lower link of the tractor based on the four-bar mechanism. According to the actual use requirements and the testing standards, the critical components in the device were designed. The dynamic analysis of the load-lifting device was carried out by dynamic simulation, and the component strength in the machine was checked by the finite element simulation method. The results showed that the designed device could realize the hooking and connection of the lower link without an artificial method. The average cost of the device was 5.13 s to realize the connection with the lower link, and it took 7.30 s to raise the lower hitch point to a set height, about 750 mm. The loading test showed that the device could keep the loading force of the lower link stable during the lifting process. The designed device could shorten the detection time of the tractor hydraulic linkage and improve the cost, safety, and efficiency of detection. The research could provide a reference for the design of hydraulic linkage detection devices for the large-medium horsepower tractors and help realize the intelligent detection of tractors.

TIMBRAL ALTERNATIONS IN TCHAIKOVSKY’S VIOLIN CONCERTO AS A MULTIFUNCTIONAL SYSTEM

The purpose of the article is to consider the alternations in Tchaikovsky’s Violin Concerto as a multifunctional system. The methodology includes score analysis as a way to determine the functions of different instruments in the Concerto and variants of their interaction; stylistic analysis is applied in order to highlight the specific features of the presentation in the orchestra of Tchaikovsky; comparative method allows us to compare the features of the orchestra in different concertos of other composers. The scientific novelty lies in the interpretation of the alternations in the Violin Concerto as an interconnected system with multifaceted influence. This paper aims to examine timbral alternations in the Concerto. On the first layer, there are alternations as a means to expose musical material: the change of timbre becomes an impetus to deploy the theme. On the second layer, there are alternations as a means of expression: a lyrical mood receives a touch of joy, a dramatic component strength, the foreground/background comparisons give a three-dimensional effect. On the third level, the alternations have form-defining function. They mark the end of a section when thematically different but emotionally identical material appears; recall the ‘remote alternations’ (tutti – tutti frame the development in the first movement). On the fourth layer, the alternations reflect Tchaikovsky’s style: his reliance on the strings’ timbers, particular attention to woodwind instruments and the horn, and a number of ‘in-the-orchestra’ soloists. Conclusions. The alternations enhance the concertizing effect, enforce the timbre and texture contrasts, add particular dynamization, and contribute to the active involvement of the orchestra in a development process by making the interaction between the soloist and the orchestra, and within the orchestra itself, much more expressive. Such a diversity of alternations creates a multifunctional system that became a distinctive feature of the Concerto.

Orbital Ultrasonic Welding of Ti-Fittings to CFRP-Tubes

Hybrid structures are important for the automotive and aeronautical industry as they have the potential to reduce vehicle or aircraft weight and to improve fuel efficiency. Continuous ultrasonic metal welding is a promising technique for hydraulic applications in aircraft to realise tubular metal/fiber reinforced polymer (FRP) hybrids. Fluid proof connections between dissimilar components can be joined by continuous welding seams. Tubular metal/FRP hybrids, produced by a new advanced variant of ultrasonic metal welding, are investigated as a potential substitute for metallic hydraulic tubes. The oscillating welding system moves around the tubular joining partners to generate a sealed orbital connection. Homogeneous joint quality is required to assure the requested component strength. Therefore, the amplitude of sonotrode displacement and the welding force are controlled to keep the induced welding energy constant and the joint quality uniform. High mechanical strength is required for a safe application in the 5000 psi hydraulic system of current and future aircraft concepts. For this study metal injection molded (MIM) titanium fittings (TiAl6V4) and carbon fiber reinforced PEEK (CF-PEEK) tubes were investigated. Process parameters for metal/FRP hybrid joining were evaluated considering their mechanical and technological properties, as well as the microstructure of the hybrid interfacial area. The entire joining area of tubular joining partners has to be in close contact before welding to assure a continuous tight joint. Hence, the titanium fitting is thermally shrunk onto the CFRP tube before ultrasonic welding. The presented orbital ultrasonic welding technology was developed for prospective industrial use and future applications of ultrasonically welded tubular multi-material-components.

Gompertz Fréchet Strength of a component between two stresses Reliability Estimation

In this paper, the reliability of the stress-strength model is derived for probability P( <X< ) of a component strength X between two stresses , , when X and , are independent Gompertz Fréchet distribution with unknown and known shape parameters and common known scale parameters. Different methods used to estimate R and Gompertz Fréchet distribution parameters which are [Maximum Likelihood, Least square, Weighted Least square, Regression and Ranked set sampling methods], and the comparison between these estimations by simulation study based on mean square error criteria. The comparison confirms that the performance of the maximum likelihood estimator works better than the other estimators.

Berücksichtigung des Zähnezahleinflusses bei der Bestimmung der Bauteilfestigkeit von Zahnrädern mit experimentell ermittelten Zahnfußtragfähigkeitskennwerten/Consideration of the Influence of the Number of Teeth for the Determination of the Component Strength of Gears with Experimentally Determined Load Carrying Capacity Parameters

Zahnfußtragfähigkeitskennwerte für Zahnräder werden in der Praxis üblicherweise in Pulsator- oder Laufversuchen ermittelt. In den genannten Prüfverfahren liegen, bedingt durch den Aufbau des Prüfgeräts, unterschiedliche Beanspruchungen in den zu prüfenden Zahnrädern vor. Dies kann dazu führen, dass für das selbe Bauteil je nach Prüfverfahren unterschiedliche Tragfähigkeitskennwerte ermittelt werden. Es wird ein statistisches Modell vorgestellt, das den Einfluss der Zahl der beanspruchten Zähne auf die Tragfähigkeitskennwerte eines Zahnrads berücksichtigt, um eine zuverlässige Auslegung eines Getriebesystems sicherzustellen. Basierend auf der Modifikation eines bestehenden Modells kann ein relevanter statistischer Zähnezahleinfluss im Bereich praxisrelevanter Zähnezahlen nachgewiesen werden. Für die praktische Anwendung wurden aus den Ergebnissen der Auswertung des statistischen Modells einfach anwendbare Methoden zur Umwertung von Festigkeitskennwerten im Auslegungsprozess abgeleitet. Diese ermöglichen eine zuverlässige Auslegung von Getriebesystemen, die im Kontext steigender Leistungsdichte und der Umsetzung von Leichtbaukonzepten zunehmend an Bedeutung gewinnt. Die mathematische Formulierung des Ansatzes ermöglicht die einfache Anpassung für die Auswertung anderer Schadensarten, Verteilungsformen und Versuchsstreuungen.

Autonomous Instrumentation for Measuring Spontaneous Electromagnetic Emissions in Mining

This article presents the design of an innovative receiver capable of identifying electric and magnetic components of electromagnetic fields. The receiver senses and records electromagnetic disturbances generated as mine tunnels collapse. It offers excellent operating specification and the ability to sense and log magnetic and electrical component strength values in real time. The paper analyzes the data obtained with the use of a system installed in a working mine and attempts to determine hazards resulting from increased rock stress levels that, cause spontaneous EM emissions.

Characterization and Modeling of Intermetallic Phase Formation during the Joining of Aluminum and Steel in Analogy to Co-Extrusion

The reinforcement of light metal components with steel allows to increase the strength of the part while keeping the weight comparatively low. Lateral angular co-extrusion (LACE) offers the possibility to produce hybrid coaxial profiles consisting of steel and aluminum. In the present study, the effect of the process parameters temperature, contact pressure and time on the metallurgical bonding process and the development of intermetallic phases was investigated. Therefore, an analogy experiment was developed to reproduce the process conditions during co-extrusion using a forming dilatometer. Based on scanning electron microscopy analysis of the specimens, the intermetallic phase seam thickness was measured to calculate the resulting diffusion coefficients. Nanoindentation and energy dispersive X-ray spectroscopy measurements were carried out to determine the element distribution and estimate properties within the joining zone. The proposed numerical model for the calculation of the resulting intermetallic phase seam width was implemented into a finite element (FE) software using a user-subroutine and validated by experimental results. Using the subroutine, a numerical prediction of the resulting intermetallic phase thicknesses is possible during the tool design, which can be exploited to avoid the weakening of the component strength due to formation of wide intermetallic phase seams.