Safe Design ??

RAMGANESH

Dear All,

 

I am currently working on some static analysis of the mounting plate in which very high load is acting (approx 5000 tons) .Material used is Mild steel. I am getting displacement of 13 mm and the vonmises stress is 1200 mpa. at the constraints and some major area around 500-600 mpa. How can i conclude the design is safe or not ? 

 

Thanks

RAM

Rahul Rajan_21763

see attached screenshot for Linear static analysis.

<?xml version="1.0" encoding="UTF-8"?>

RAMGANESH

Dear Rahul ,

 

I had some knowledge about the topic which you have shared but my problem is due to high load . can i decide the design safe by considering the max stress where the deflection is more. if it is below the yield then it will be safe know???

 

Thanks

RAM

<?xml version="1.0" encoding="UTF-8"?>

<?xml version="1.0" encoding="UTF-8"?>

Rahul Rajan_21763

5000 tonnes seems to be too high.How about structure dimension?

In Hyperview you are checking elemental results or nodal for stresses/ Averaging method?

RAMGANESH

Structure dimensions are 2500 x 2500 x 185 mm

I have used the simple average method to calculate the stress

Rahul Rajan_21763

could you share relevant file to take a look in to your model?

RAMGANESH

Dear Rahul ,

 

What is nodal difference method to calculate the stress?

 

Rahul Rajan_21763

Normally i prefer to check corner results with averaging method set to simple.In Optistruct. by default you would get element centroid based results.

In Hyperview contour panel you would find By corner option which would get activate while preprocessing in Hypermesh.Under global output request set stress results to corner.

RAMGANESH

Dear Rahul,

There is no difference in stress results by activating the corner option.

 

But by using Difference method the stress results are different? What Difference method to calculate stress in Hyperview?

 

Altair Forum User

Hi Ram,

This averaging method simply calculates the difference between  maximum and minimum stress value at each node. This averaging method can be used to see the stress difference across adjacent element .

Rahul Rajan_21763

For time being apply lower load like 1000 tonnes and see whether it behaves linearly.Share snapshot of loads and boundary condition.

RAMGANESH

Dear Rahul,

 

PFA

<?xml version="1.0" encoding="UTF-8"?>

<?xml version="1.0" encoding="UTF-8"?>

Rahul Rajan_21763

could you create RBE2 in all four hole location and constraint master node with all dof & run. 

RAMGANESH

Dear Rahul,

 

By creating the RBE2 and giving constraints to it then running the model gives the same result.

 

Currently going with increasing the model thickness.

 

Thanks

RAM

Rahul Rajan_21763

Thanks for the update.Let us know if that approach helps to reduce stresses.