General Mechanical

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Calculating Reactions & Stresses for Weld Design

• Siddharth Manda
Subscriber

I have modelled a simple flat plate ( 500mm x 20mm thick) welded on 3 sides ( 1m + 1m+ 0.5m) on a base plate (30mm plate), which is fixed at the 4 edges. I have applied a load of 5.0E5 N (1000N/mm x 500mm).

In order to tap the weld stress or the reaction force, i followed 3 types

1) Finding Shear Stress in XZ Plane

The Shear Stress seems to be nullified and effective shear stress is 0 MPa. Any reason for this behaviour ? I wanted to take this stress and design my weld for lateral shear stress.  How is the Shear Stress Calculated ? I tried capturing nodal force and dividing the shear area to get stress, but value seems to be different than the stress shown below

2) Finding Normal Stress in Z Direction

How is Normal Stress Calculated at the junction of weld interface. I understand that the front yellow zone is just the load / area which comes to 50MPa. But as the welding starts, how are the stresses generally computed ?

3a) ENFO Vector Command to get the Force

Trying to directly get the Forces from ENFO Command. I got the below detail. For some reason, 50000N is acting in the reverse direction at two corner nodes and my effective force comes down to 4.5E5 (5.0E5 - 5.0E4). What is the reason for this ?

3b) ENMO Vector Command to get the moment - I wanted to know abt the direction of Local Moment what this refers abt ? My Moment means abt XZ Plane ? Although the entire moment is actually close to zero.

• Ashish Kumar
Forum Moderator

Hi,

Please see if the following link helps: How to Size a Fillet Weld Using Finite Element Analysis (FEA) | Apollo Engineering (apolloedge.com)

Regards,

Ashish Khemka

• Siddharth Manda
Subscriber

Yes the link was helpful, but in my case, for the calculation of ENFOZ, the reaction is not coming as the load application, 50000N has been deducted and acting as a reaction at the two points as shown in snap below.