STRESS ANALYSIS EXPLANATION IN 1 BAR PRESSURE LOAD FOR THIN SHEET METAL

[Anonymous]

I NEED TO SEE DEFLECTION OF CASING PANEL AT 1 BAR.I HAVE DONE STRESS ANALYSIS OF 1.6 MM THICK  DUCT FOR PRESSURE 1 BAR. BUT THE RESULT SHOWS MAXIMUM STRESS UPTO 1700MPA. WHICH IS MORE THAN Y.S. OF STEEL. PLEASE SUGGEST ME WHICH CONSIDERATION IN ANALYSIS WENT WRONG. ATTACHED HERE ANALYSIS REPORT.

[KKizildemir]

Hi @Anonymous ,

I am not able to see your global X Y Z axes so it is very hard to tell about your report's graphics. Can you please share your design files? So we can make deeper comments about them.

Kind regards,

[Anonymous]

HERE ATTACHED THE MY DESIGN PART . THE PART IS OF ELEVATOR DUCT. I HAVE TO CHECK THE SIDE PLATES OF DUCT AT 1 BAR PRESSURE. IT IS ASSEMBLY OF 2 PARTS. I HAVE SHARED THE ASSEMBLY PART HERE. I AM CONFUSED WITH MAXIMUM ALLOWABLE STRESS OF STEEL WHICH IS 207 MPA. BUT IN MY ANALYSIS MAX VALUE SHOWS 1940MPA. FOR 1 1 BAR PRESSURE LOAD. WHEN I CHANGE MESH SETTING THE MAX STRESS VALUE COMES DOWN. PRACTICALLY HOW ITS POSSIBLE? WHEN WE ARE USING SAME PLATE FORANALYSIS & PRESSURE LOAD WILL DISTRIBUTE ALL OVER THE PART.

PLEASE SUGGEST ME WHERE I AM GOING WRONG?

[Anonymous]

HERE ATTACHED THE MY DESIGN PART . THE PART IS OF ELEVATOR DUCT. I HAVE TO CHECK THE SIDE PLATES OF DUCT AT 1 BAR PRESSURE. IT IS ASSEMBLY OF 2 PARTS. I HAVE SHARED THE ASSEMBLY PART HERE. I AM CONFUSED WITH MAXIMUM ALLOWABLE STRESS OF STEEL WHICH IS 207 MPA. BUT IN MY ANALYSIS MAX VALUE SHOWS 1940MPA. FOR 1 BAR PRESSURE LOAD. WHEN I CHANGE MESH SETTING THE MAX STRESS VALUE COMES DOWN. PRACTICALLY HOW ITS POSSIBLE? WHEN WE ARE USING SAME PLATE FORANALYSIS & PRESSURE LOAD WILL DISTRIBUTE ALL OVER THE PART.

PLEASE SUGGEST ME WHERE I AM GOING WRONG?

ITS TYPE MISTAKE.  LOAD IS OF 1 BAR 

[Anonymous]

HERE ATTACHED THE MY DESIGN PART . THE PART IS OF ELEVATOR DUCT. I HAVE TO CHECK THE SIDE PLATES OF DUCT AT 1 BAR PRESSURE. IT IS ASSEMBLY OF 2 PARTS. I HAVE SHARED THE ASSEMBLY PART HERE. I AM CONFUSED WITH MAXIMUM ALLOWABLE STRESS OF STEEL WHICH IS 207 MPA. BUT IN MY ANALYSIS MAX VALUE SHOWS 1940MPA. FOR  1 BAR PRESSURE LOAD. WHEN I CHANGE MESH SETTING THE MAX STRESS VALUE COMES DOWN. PRACTICALLY HOW ITS POSSIBLE? WHEN WE ARE USING SAME PLATE FORANALYSIS & PRESSURE LOAD WILL DISTRIBUTE ALL OVER THE PART.

PLEASE SUGGEST ME WHERE I AM GOING WRONG?

[KKizildemir]

Hi @laser26SW3 ,

I've updated your model files and simulation case. Please watch the preparation video first. And please find model and simulation files attached.

1. I've divided your single ipt file into 2 ipt files and assembly them together in an iam file because we need to assume your sheet metal parts with no thickness to reduce the number of mesh elements. This is applicable for sheet metal parts.
2. You've not applied correctly the pressure input on top and bottom part. I've split this part's inner face to apply pressure on the selected face below. That's much more correct:
3. I've applied pin constrains on the holes at both end instead of applying fixed constraints on the end faces.
4. I've defined bonded contacts on the parts between matching holes.
5. Please see the simulation settings below: 

As a result, you can see the stress concentration around your holes. That is much more accurate. I've selected simulation material as steel. Your 0,1 MPa Pressure BC is too high. It equals to F= 0,1 [N/mm^2] X 507815 [mm^2] = 50781,5 [N] = 5078 [kg] .That's why max stress is too high! Max deformation is about 60 mm!

Regards,

Screencast will be displayed here after you click Post.

179bcbbc-58d1-4b76-b267-3b9401765c54

[Anonymous]

THANKS. ALSO I NEED TO KNOW EEFECT OF MESH SETTING IN REAL LIFE APPLICATION. IF I USE AVG. ELEMENT SIZE 1 , MAX STRESS COMES DOWN. BUT IN ACTUAL WE APPLY SAME LOAD ON SURFACE. PRACTICALLY I WILL NOT MAKE ANY CHANGES IN PANEL . WHICH MESH SEETING I SHOULD CONSIDER IN REAL APPLICATION.  HERE I ATTACHED ANOTHER PART WITHOUT CONSIDERING BOLTING  WITH DIFFERENT MESH SETTING. PLEASE GUIDE ME.

[Anonymous]

CANNOT OPEN YOUR FILE, I AM USING INVENTOR 2016.

[Anonymous]

I HAVE ATTACHED ONE PART AS PER YOUR SUGGESTED MAIL. PLEASE CHECK & TELL IS IT OK.