11-10-2011 03:16 AM
Task:
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On components exposed to high vibration, it is often inertial forces that provide the greatest the load. One way to test the strength of these components is by using a shaker table. By first measuring the accelerations which the component is exposed to the test track or at a customer to the acceleration as a function of frequency are developed, a so-called power density spectrum (PSD). This then used as the driving signal to skakbordet where the tested component is fixed. Using Finite Element program, the same can be done with a virtual shaker table. The advantage is that component's strength can be calculated before an expensive prototype. Many variations can be also tested in a short time. Instead of a calculation in the time domain, a calculation by a frequency response analysis using the PSD produced for use in skakprovningen. The is performed by the FE program first calculates the system's natural frequencies and with a estimated modal damping estimates the transfer function of the system. Thereafter, the response, distributed over the frequencies, obtained by excitations from the PSD spectrum. That is, the acceleration as a function of frequency times the system transfer function gives the response (eg, voltage) function of frequency. The result is a power spectrum in each calculation point in the model for all voltage components. We uses this method today for calculating the strength of the components are assumed to have a fatigue limit. The evaluation is made when the "infinite life". But no clear fatigue limit Not available for welders but these must be evaluated in a finite lifespan. Mission Statement Study the methods described in the literature and develop a method for fatigue assessment of welds. Verify the method by perform a load measurement at an appropriate component containing welding and fatigue try this and calculate the lifetime of the proposed method. Objectives Develop a routine for calculating the fatigue assessment of weld to do with the PSD.
This task can be done by Abaqus and MATLAB.
Dobut
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Can we do it with Labview?. I am good at labVIEW tham MATLAB. So, I don't know wheather i can do it in labVIEW or not. I have been working with Signal processing. SO i hope it is possible to do it in labview but not sure.