Performance Evaluation and Frequency Response Analysis of a Two Stage Two Spool Electrohydraulic Servovalve with a Linearized ModelNitesh MONDAL & Biswanath DATTA
This article focuses on the performance study and frequency response analysis with the state space model of a linearized two stage two spool non-conventional electrohydraulic servovalve from a set of nonlinear state equations. The performance of this valve depends on many valve geometries and fluid parameters. This non-conventional electrohydraulic servovalve is controlled by a pressure controlled pilot, which generates a differential pressure between the upper and lower chambers of two spools. This differential pressure acts...
Virtual additive manufacturing (AM) is one of the new directions of research that is necessary to improve AM technology. Abaqus/SIMULIA software allows to simulate the whole process using user subroutines to expand solver capabilities. Two of the most important subroutines are UepActivationVol and UMATHT. The UepActivationVol is related to an activation of elements in accordance with the defined path of the process. The second one the UMATHT is used to implement and combine thermal and...
Crystallization Kinetics of Polyamide 2200 in the Modelling of Additive Manufacturing Processes by FE AnalysesPaweł BAJERSKI, Ryszard B. PĘCHERSKI, Damian CHUDY & Leszek JARECKI
The thermoplastic polymers present amorphous or semi-crystalline structures which are very important factors in describing volumetric shrinkage. The thermoplastic materials are commonly used for production of daily life products, industrial or as the prototypes. Different techniques of manufacturing polymer structures are considered like: injection molding, extrusion, milling, additive manufacturing (AM). AM is a very fast developing field in the manufacturing and research. Unfortunately, components or prototypes made using the thermoplastic semi-crystalline materials in 3D techniques...
The Impact of Temperature Oscillations and Heat Transfer Conditions in Thick-Walled Elbows and Tubes on the Local Stress-Strain Behaviour During the Fast Start-Up of Power BoilersJerzy OKRAJNI & Krzysztof WACŁAWIAK
The paper presents results of tests designed for predicting the behaviour of components subjected to variable temperature and mechanical loading conditions. Elbows and tubes, as examples of components widely used in power plant pipelines, have been examined. This analysis includes a description of model characteristics, the operating parameters of devices under industrial conditions, and the results of computational modelling (FEM).
Development of Non-Contact Fatigue Crack Propagation Monitoring Method Using Air-Coupled Acoustic Emission SystemTakuma MATSUO & Daisuke HATANAKA
A monitoring system for fatigue crack propagation was developed using a non-contact acoustic emission (AE) monitoring system. The AE signals generated during the plane bending fatigue test were first monitored. The AE generation rate increased after approximately 0.5 of the fatigue life ratio. The maximum amplitude of the AE signals increased with a tendency similar to that of the crack propagation. The sensor sensitivities for the flat and arced surfaces were then compared. The sensitivity...
Poznań University of Technology4
Phetchabun Rajabhat University2
AGH University of Science and Technology2
Cracow University of Technology1
Dorodnitsyn Computing Centre1
China University of Mining and Technology1
Lublin University of Technology1
Przemysłowy Instytut Motoryzacji1
Jan Grodek State Vocational Academy in Sanok1