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#11690 - 06/14/07 10:20 AM Load Cases for static Analysis of Earthquake
Mr. Shrimp Offline
Member

Registered: 06/13/07
Posts: 39
Loc: ConcepciĂłn, Chile
Estimated
I send a personal interpretation for the static analysis of the loads cases for earthquake.(Not linear analysis with Earthquake)

Bearing in mind that in the zone where my analyses are projected are considered to be cases of earthquake in the vertical axis.

Next, I define the combination of Loads cases for the Not linear analysis with Earthquake

Not linear analysis with Earthquake

LOADS CASES - STRESS TYPE - OUTPUT STATUS - COMB METHOD - MONITORING RESULT
1: W+T1+P1 - OPE - Supress - 0 - 0
2: W+T2+P1 - OPE - Keep - 0 - Restraints, (Loads)
3: W+P1 SUS - Keep - 0 - Stress Code & Restraints, (Loads)
4: W+T1+P1+U1 - OCC - Supress- 0 - 0
5: W+T1+P1+U2 - OCC - Supress- 0 - 0
6: W+T1+P1+U3 - OCC - Supress- 0 - 0
7: L1-L3 - EXP - Keep - lgebraic - Stress Code
8: L5-L1 - OCC - Supress - Algebraic - 0
9: L6-L1 - OCC - Supress - Algebraic - 0
10: L7-L1 - OCC - Supress - Algebraic - 0
11: L8+L9 - OCC - Supress - SRSS - 0
12: L8+L10 - OCC - Supress - SRSS - 0
13: L2+L11 - OCC - Keep - Scalar - Restraints, (Loads)
14: L2-L11- OCC - Keep - Scalar - Restraints, (Loads)
15: L2+L12- OCC - Keep - Scalar - Restraints, (Loads)
16: L2-L12- OCC - Keep - Scalar - Restraints, (Loads)
17: L3+L11 - OCC - Keep - Scalar - Stress Code
18: L3-L11 - OCC - Keep - Scalar - Stress Code
19: L3+L12 - OCC - Keep - Scalar - Stress Code
20: L3-L12 - OCC - Keep - Scalar - Stress Code
21: L13+L14....L19+L20 - OPE - Keep - SignMax - Restraints, (Loads)
22: L13+L14....L19+L20 - OPE - Keep - SignMin - Restraints, (Loads)

where:
T1&P1.- They are Design conditions
T2&P2.- thet are Operations conditions

wait for commentaries

thanks


Edited by Mr. Shrimp (06/14/07 10:29 AM)
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Juan Pablo Quiroz - Pares y Alvarez

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#11695 - 06/14/07 06:31 PM Re: Load Cases for static Analysis of Earthquake [Re: Mr. Shrimp]
Richard Ay Offline
Member

Registered: 12/13/99
Posts: 6226
Loc: Houston, Texas, USA
Design temperatures and pressures are typically not used in a flexibility analysis. Therefore Case 1 (and all cases built on it) are not needed here.

From your description, Case 2 should use P2, not P1.

Cases 4 – 6 should use your T2/P2, the operating conditions.

Case 7 should be L2 – L3 (operating minus sustained).

Cases 8 – 10 should be L4-L2, L5-L2, and L6-L2.

Cases 11 and 12 are ok (I presume U2 is vertical).

Cases 13-20 are ok.

Cases 21 and 22 are incorrect. These cases should be L13+L14+L15+L16. Do not include 17 – 20 here because these later cases are a stress summation.
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Richard Ay - Consultant

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#11698 - 06/14/07 07:57 PM Re: Load Cases for static Analysis of Earthquake [Re: Richard Ay]
John C. Luf Offline
Member

Registered: 03/25/02
Posts: 1110
Loc: U.S.A.
Mr. Shrimp....

You need some training asking a bunch ofd questions on a web forum is not going to cut it! Hire an experienced competent pipe flex person and learn from them or attend a COADE seminar or download and read all the free MEN newsletters from this site, buy and read the code books and some of the references listed on this site or continue your plodding questions.
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John C. Luf

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#11843 - 06/25/07 01:09 AM Re: Load Cases for static Analysis of Earthquake [Re: John C. Luf]
Ioana Campbell Offline
Member

Registered: 06/21/07
Posts: 6
Loc: New Plymouth, New Zealand
How about loads cases for static analysis of wave

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#11858 - 06/25/07 06:50 AM Re: Load Cases for static Analysis of Earthquake [Re: Ioana Campbell]
Richard Ay Offline
Member

Registered: 12/13/99
Posts: 6226
Loc: Houston, Texas, USA
Wave analysis is a little different because you likely be working to one of the offshore piping codes. These codes really want a single load case with all operational and environmental loads acting concurrently (but you wouldn't combine earthquake and extreme wave).

So you would want a load case similiar to:

W+P1+T1+F1+WAV1+WIN1
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Richard Ay - Consultant

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#12038 - 07/04/07 07:26 PM Re: Load Cases for static Analysis of Earthquake [Re: Richard Ay]
Mr. Shrimp Offline
Member

Registered: 06/13/07
Posts: 39
Loc: ConcepciĂłn, Chile
That it happens if for these cases of load a restriction is added type SNB

LOADS CASES - STRESS TYPE - OUTPUT STATUS - COMB METHOD - MONITORING RESULT
1: W+D1+T1+P1 - OPE - kEEP - 0 - 0
2: W+P1 SUS - SUPRESS - 0 - Restraints, (Loads)
3: W+P2 SUS - Keep - 0 - Stress Code & Restraints, (Loads)
4: W+D1+T1+P1+U1 - OPE - Supress- 0 - 0-------ACTIVE SNUBBERS
5: W+D1+T1+P1+U2 - OPE - Supress- 0 - 0-------ACTIVE SNUBBERS
6: W+D1+T1+P1+U3 - OPE - Supress- 0 - 0-------ACTIVE SNUBBERS
7: L1-L2 - EXP - Keep - lgebraic - Stress Code
8: L5-L1 - OCC - Supress - Algebraic - 0
9: L6-L1 - OCC - Supress - Algebraic - 0
10: L7-L1 - OCC - Supress - Algebraic - 0
11: L8+L9 - OCC - Supress - SRSS - 0
12: L8+L10 - OCC - Supress - SRSS - 0
13: L2+L11 - OCC - Keep - Scalar - Restraints, (Loads)
14: L2-L11- OCC - Keep - Scalar - Restraints, (Loads)
15: L2+L12- OCC - Keep - Scalar - Restraints, (Loads)
16: L2-L12- OCC - Keep - Scalar - Restraints, (Loads)
17: L3+L11 - OCC - Keep - Scalar - Stress Code
18: L3-L11 - OCC - Keep - Scalar - Stress Code
19: L3+L12 - OCC - Keep - Scalar - Stress Code
20: L3-L12 - OCC - Keep - Scalar - Stress Code
21: L13+L14+L15+L16 - OPE - Keep - SignMax - Restraints, (Loads)
22: L13+L14+L15+L16 - OPE - Keep - SignMin - Restraints, (Loads)

P1;T1 OPERATION CONDITIIONS
P2; DESIGNE PRESURE

MY DOUBT THIS IN THAT IF MUST BE the ITEM, L4, L5, L6 OPE Or OCC

tHANKS


Edited by Mr. Shrimp (07/04/07 07:27 PM)
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Juan Pablo Quiroz - Pares y Alvarez

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#12042 - 07/04/07 10:39 PM Re: Load Cases for static Analysis of Earthquake [Re: Mr. Shrimp]
Richard Ay Offline
Member

Registered: 12/13/99
Posts: 6226
Loc: Houston, Texas, USA
Call them OCC cases. You have the output supressed, so no one will accidentally use the stresses - this is good.
_________________________
Regards,
Richard Ay - Consultant

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