Wyniki wyszukiwania - BazTech

1

Modernized Resonant Column and Torsional Shearing Apparatus With Multipoint Contactless Displacement Detection System

Bujko Marcin, Bocheńska Marta, Srokosz Piotr, Dyka Ireneusz

Studia Geotechnica et Mechanica

|

2023

|

Vol. 45, nr s1

382--394

EN

In this study, a modification of resonant column/torsional shearing (RC/TS) apparatus was proposed to perform a qualitative analysis of a noncohesive soil specimen vibration during RC tests. An additional multipoint displacement detection system was installed in the RC/TS WF8500 device. In the new measuring system, 48 mini-magnets are attached to the side surface of a cylindrical soil specimen, creating a regular grid of measuring points. Around 48 Hall sensors (Honeywell SS495A1) are used to measure changes in the magnetic field strength due to the movement of the corresponding magnets on the surface of the specimen subjected to dynamic torque. The Hall sensor generates an analog signal that is proportional to the change in the magnetic field. The measurements are collected with a newly developed data acquisition system that consists of a set of analog-to-digital converters and a set of ARM (Advanced RISC (Reduced Instruction Sets Computing) Machine) microcontrollers. The measurement system is controlled with a dedicated software, ControlRec, developed by the authors. The measurements are taken synchronically with and independently from the standard RC test procedure. The new measuring technique allows to observe displacements of the 48 points on the specimens’ surface with over 4 times higher sampling rate than in the original measuring system. As a result, additional effects related to the mechanical wave propagation through soil specimen were observed (local disturbances in distribution of vibration amplitudes or significant displacements near the bottom end of the specimen, which is assumed to be fixed in the standard RC/TS results analysis), that could not be identified using the standard equipment of the device.

2

Influence of Experimental Setup Parameters on Ultrasonic Assisted Micro-Upsetting

Presz W.

Archives of Metallurgy and Materials

|

2020

|

Vol. 65, iss. 1

423--431

EN

The progressive development of miniature systems increases the demand for miniature parts. Reducing the size of manufactured components on one hand is a serious challenge for traditional technologies, but on the other hand, mainly by removing the energy barrier opens the possibility of using other unconventional techniques. A good example is the ultrasonic excitation of the punch during the micro-upsetting process. The anti-barreling phenomenon and dependent on the amplitude of vibrations, intensive deformation of the surface layers in contact with the tools at both ends of the sample was noted. Based on the measured strains and stresses, an increase in temperature in the extreme layers to approx. 200°C was suggested. By adopting a simplified dynamic model of the test stand, the possibility of detaching the surface of the punch from the surface of the sample was demonstrated.

3

Some aspects of the experimental assessment of dynamic behavior of the railway track

Solonenko V., Mahmetova N., Musayev J., Kvashnin M., Alpeisov A., Zhauyt A.

Journal of Theoretical and Applied Mechanics

|

2017

|

Vol. 55 nr 2

421--432

EN

The paper suggests application of an experimental method for the assessment of the dynamic effect of a locomotive underframe on the railway track. The assessment is to be based on spectral analysis of the response of structural elements of the railway track undergoing a shock pulse. Application of digital measuring systems for monitoring of motion of the train is also proposed.

4

Analiza efektów dynamicznych procesu cięcia przemysłowego

Świłło S., Czyżewski P.

Hutnik, Wiadomości Hutnicze

|

2016

|

Vol. 83, nr 1

34--39

PL

W prezentowanym opracowaniu autorzy skoncentrowali się na wskazaniu potrzeby zastosowania odpowiedniego modelu komputerowego MES do symulacji numerycznej dynamicznego procesu cięcia. Ponadto, podjęto tematykę pomiaru doświadczalnego odkształceń i określenia momentu pękania. W wyniku opracowanego systemu do nadzorowania przebiegu procesu cięcia na prasie mimośrodowej powstał oryginalny układ pomiarowy do ultra-szybkich pomiarów przebiegu procesu cięcia. W pierwszej części artykułu, autorzy demonstrują zaprojektowane stanowisko do realizacji cięcia przemysłowego w trakcie realizacji pozyskiwania danych pomiarowych. W drugiej części, przedstawiono udaną próbę zarejestrowania i wskazania na szereg charakterystycznych zjawisk, które są udziałem jedynie dynamiki procesu. Na zakończenie przedstawiono zalecenia do realizacji komputerowej symulacji procesu cięcia dynamicznego.

EN

The presented study is generally focused on the description of FEM model verification for the industrial blanking process. Additional problems are also discussed, which included experimental strain measurement and monitoring of material crack propagation. As a results of investigation a specially equipped measurement device was designed to obtain accurate material flow results, based on a ultra- speed camera and an image processing analysis. First, the authors present the design measurement equipment and apparatus for the blanking process for industrial application after the workflow data collection. Second the authors demonstrate a successfully pointed several typical moments of the blanking process, that are resulted of process speed. Finally, the authors present recommendation for the computer simulation (FEM) for the blanking process analysis is provided.

5

Factors affecting the choice of fault duration in transmission lines for computation of dynamic effects in EHV distribution substations

Frąckowiak R., Piechocki P.

Computer Applications in Electrical Engineering

|

2013

|

Vol. 11

176--188

EN

In the paper, the method of assessment of the fault duration in transmission line regard¬ing dynamic effects in the EHV distribution stations with flexible bus conductors is pre¬sented. Expected yearly frequency of exceeding the indicated dynamic forces has been assumed to be a criterion of choice of the short-circuit duration values. Results of simula¬tions carried out using Monte Carlo technique have shown the influence of parameters of the distribution substation and devices installed in it (nominal voltage, short-circuit capaci¬ty, unreliability of circuit-breakers and protections, EAZ configurations) on suggested fault duration values in the engineer-type short-circuit computations.