The project content was a computational verification of the requirements according to EN12663 as well as IEC61373 (vibration test) for the housing construction of a roof mounted air conditioning unit of a rail vehicle.
In addition to the standard verification of static strength and fatigue strength according to EN12663, a dynamic calculation of the vibration test situation according to IEC61373 was also performed.
For this purpose, a modal broadband excited (random response) stress analysis was performed under the given excitation spectra and the corresponding results were evaluated in the fatigue range (LIMIT® software).
The tests according to IEC61373 still had to be performed in order to test other system components. These tests were completed without damage at the first attempt.
The picture above shows one of the basic vibration modes of the device, the one below shows the calculated fatigue weld strengths on a detail.