Automobile parts are often used in a vibrating environment, with vibrations caused by the engine and by driving. If resonance occurs in automotive components due to external vibrations, this can lead to abnormal noise and damage.
Therefore, when designing a product, a modal analysis (eigenvalue analysis) using CAE should be carried out in advance.
It is therefore necessary to check that the eigenvalues of the designed parts are higher than the ambient vibration frequency.
The eigenvalues are determined by the following equation
The equation shows that the higher the product stiffness, the higher the mass and the lighter the mass, the higher the eigenvalue.
So how exactly can stiffness be increased?
Below are the results of a CAE validation.
Enter general polyethylene properties for a simple flat model
If the model had one constraint point, the eigenvalue would be 25.931 Hz.
Then, when constrained at two holes, the eigenvalue is 194.14 Hz.
The above shows that increasing the number of restraining points increases the stiffness of the product, which in turn increases the eigenvalues. If the materials used or the shape of the product cannot be changed due to constraints, increasing the number of restraining points is the most reasonable measure.
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