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          Domain

          4.1 - Eco-nano-tehnologii

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Abstract

The international norms require that during the railway vehicles homologation, they are subject to complex procedures for validating the structural strength to fatigue and extreme loads. Bogie frames presents a particular situation because their validation at fatigue by tests requires a laboratory with a significant number of equipment, capable of reproducing the dynamic cycles and a long time testing (4-6 months). Given the financial implications and the long time testing, the standards admit that tests for fatigue validation can be replaced by other methods that demonstrate the strength to fatigue, among them, the analytical method playing an important role, only if the analytical model to be correct realized and calibrated by tests. 
For Softronic, which is the locomotives manufacturer, critical are the following problems: 
- Validation to the static loads and fatigue strength of bogie frames for locomotives that are already in circulation, and for those who will equip the new types of locomotive;
- Validation to the mechanical strength of the control and board equipment, in accordance with international norms and vibration state at the mounting place. 
Project objectives: 
- Validation of some combined technologies, analytical and experimental of low energy intensity, for assessment of the fatigue strength and exceptional loads of the strength structures of railway vehicles, with orientation towards the validation of bogie frames; 
- Validation of some technologies for assessment of the vibratory loads on the mounting place of the main board and control equipment and checking their mechanical strength, according to the standards and real vibration conditions at the mounting place; 
- Assimilation of technologies realized through the project by the industrial partner and their introduction in the design and manufacturing of new railway vehicles.

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The objective of the project

-Realization and validating of some combined, analytical and experimental, technologies for assessment at fatigue and exceptional loads of railway vehicles strength structure, with priority orientation towards the bogie frames validation; 
-Realization and validating of some technologies for assessment of real vibratory loads, at the mounting site of the main board and control equipment and checking their mechanical endurance, in accordance with international norms and the real loads at the functional site; 
-Assimilation of achieved technologies through the project by the industrial partner and their introduction in the design and manufacturing of new rail vehicles; 
-Development of a sustainable partnership between a company, Softronic Craiova, a research institute, INMA Bucharest and a prestigious university, University POLITEHNICA of Bucharest - Faculty of Transports.

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Estimated results

A. Combined, analytical and experimental, technology for assessment at fatigue and exceptional loads of the railway vehicles strength structure, with priority orientation towards to the bogie frames validation. 
The technology includes: 
-The measurement equipment and software for determination of the real mechanical stress (vibrations, stresses, strains) to which is subjected the strength structure of the rail vehicles under real railway traffic; 
-Software package of analysis with finite elements for fatigue and dynamic loads analysis of railway vehicle strength structures, centered on ANSYS Mechanical and ANSYS nCode DesignLife. 
-Certified laboratory for testing and calibration in domain of main parameters related to the project (forces, pressures, vibrations); 
-Procedure for collecting the experimental data; for determination of the loads duration and average values of stresses as well as of the stress-number of cycles curves. 
-Procedure for analytical assessment of fatigue and exceptional loads resistance of strength structure of rail vehicles. 
B. Technology for assessment of the vibratory loads, at the mounting place of the main board and control equipment, and for checking these to enduring mechanical stresses, in accordance with international norms and the real loads at the mounting place. 
Loads assessment at the mounting place will be done with equipment and software that already exists at coordinating partner and will be completed during the project.  The tests to enduring mechanical stresses will be done with electrodynamics shaker of about 11kN, purchased during the project, which will be used to induce the local dynamic stresses in the technologie at the point A. 
C. Two scientific articles published at ISI conferences.