Experimental investigation of the effect of thermal effects on resonance frequency changes in automotive front lighting housing component

Automotive front lighting systems are important elements both in terms of design and safety. The main purpose of these systems is to illuminate the road during night driving and to determine the presence, speed, size or direction of the vehicle to the surrounding vehicle or pedestrians. Nowadays, it is very important to determine the errors that may occur during the test phase of these systems, which are very complicated. In this study, a lighting housing made of PP TD40 material, which is formed by adding 40% by volume of talc into polypropylene (PP) which is one of the materials used in automotive industry, is connected to the electrodynamic shaker and sinus scanning test is performed in the range of 1-300 Hz. After this test, acceleration amplitude and frequency data were collected and analysis parameters such as half power points, modal constant and damping ratio were calculated. The acceleration amplitude and frequency graphs obtained from the results of the Ansys® finite element analysis program run with these parameters and the acceleration amplitude and frequency graphs of the test results were compared. The difference between the results was at most 11.3% and at least 0.26%. The time dependent acceleration data collected from the accelerometer placed on the fixture base were entered into the finite element analysis program as time dependent acceleration force and the strain data at the point determined on the 3D model were compared with the help of the nCode® program placed on the same point on the housing. The results were obtained with 12.4% difference in strain measurement. The data acquisition system's data was recalculated using various fourier transform (FT) parameters such as windowing function, overlapping, resolution and the calculated data were compared with the shaker test setup data.