local modes in gear

[bala300587]

Hi

I have just given pinion gear for SOL 103 ( Modal analysis ) . I have wondered that I found local modes at the top of the gear. Top few elements having different modes when compared to others. What could be wrong ? Image is attched below

 

[Drej]

Looks like you have elements which are overlayed onto others at the top of the pinion.

In your figure these elements are showing a mode of very low frequency (<< 0.5Hz) which I wouldn't expect. With the very few details you've given it's very difficult to offer any advice other than check your mesh.



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[bala300587]

Let me explain in detail

The pinion is hexameshed and ran 103 in nastran with steel as material property .It is just a free run , no SPCs or MPCs defined. But when I checked the results , few elements as you can see in the image behave in different manner and having different modes.

wht might be the reason?

I am sure that there are no coincident elements and all nodes are connected


thank you in advance