Coordinate system which is algined to the weldseam

[roman.gebhard5MV47]

Hello together,

my problem is that i would like to prove one weldseam with the effective notch stress method.

In FKM is written down that i have to use a Coordinate system which is algined to the weldseam.

How can i transponse this?

I can't define a coordinate system before, because i don't know where the maximum position is in advance.

I need a coordinate system with one axis parallel to the surface and one axis perpendicular to the surface, where the maximum value is positioned.

A further problem is that the surface isn't flat.

There is a radius of 1mm in the weldseam because of the effective notch stress method.

It isn't a specific Nastran in CAD problem, moreover to prove a weldseam.

Thanks in advance. 

[roman.gebhard5MV47]

Hello together,

my problem is that i would like to prove one weldseam with the effective notch stress method.

In FKM is written down that i have to use a Coordinate system which is algined to the weldseam.

How can i transponse this?

I can't define a coordinate system before, because i don't know where the maximum position is in advance.

I need a coordinate system with one axis parallel to the surface and one axis perpendicular to the surface, where the maximum value is positioned.

A further problem is that the surface isn't flat.

There is a radius of 1mm in the weldseam because of the effective notch stress method.

It isn't a specific Nastran in CAD problem, moreover to prove a weldseam.

Thanks in advance. 

[viktor.velichko]

Hello, Roman! Can you attach model of your weldseam? It will be more simple to undestand the problem. And excuse me I don't know, what FKM is?

May be you can help using idealisations with specify coordinate system. It also allows see results in the same coordinate system.

 

[viktor.velichko]

Hello, Roman! Can you attach model of your weldseam? It will be more simple to undestand the problem. And excuse me I don't know, what FKM is?

May be you can help using idealisations with specify coordinate system. It also allows see results in the same coordinate system.

 

[roman.gebhard5MV47]

To read out the stresses, one axis has to parallel to the weldseam, the other perpendicular to the weldseam.

but both are in the same plane of the surface.

 

In my case the maximum is in the radius.

The stress parallel to the weldseam, is in my model along the Y-Axis.

But the stress perpendicular to the weldseam must be tangential to surface of the maximum point in the radius.

In the Attachement is my CAD-model.

My idea is that i read out the X, Y and Z normal and shear stresses and then start a coordinate system transformation.

But i do not exactly know in which angle the maximum point is positioned.

That would may be a way, but nothing exact.

[roman.gebhard5MV47]

To read out the stresses, one axis has to parallel to the weldseam, the other perpendicular to the weldseam.

but both are in the same plane of the surface.

 

In my case the maximum is in the radius.

The stress parallel to the weldseam, is in my model along the Y-Axis.

But the stress perpendicular to the weldseam must be tangential to surface of the maximum point in the radius.

In the Attachement is my CAD-model.

My idea is that i read out the X, Y and Z normal and shear stresses and then start a coordinate system transformation.

But i do not exactly know in which angle the maximum point is positioned.

That would may be a way, but nothing exact.

[darrenlovesmusic · Accepted solution]

@roman.gebhard5MV47 

I recommend "https://link.springer.com/article/10.1007/BF03266562"

and 

https://www.springer.com/gp/book/9789811055676

The references in the article will contain more information, if you have access. Also, if you are following a design code, the instructions may be prescribed. 

[darrenlovesmusic · Accepted solution]

@roman.gebhard5MV47 

I recommend "https://link.springer.com/article/10.1007/BF03266562"

and 

https://www.springer.com/gp/book/9789811055676

The references in the article will contain more information, if you have access. Also, if you are following a design code, the instructions may be prescribed.