PLE forum - General Technical Matters

E200/48: 2 fix nodes at support

Tue, 09 Feb 2016 11:33:31 +0100

Hello,

When I have a configuration with a lot of Identifiers a lot of nodes are occupied. When I use S-AX-L in the SUPPORTS (a lot of supports) input table on certain Ple4Win gives an hardcoded error.

[attachment=757]

Why can't a defined node not be used twice? It has no theoretical background why it shouldn't. This means we have to offset the support a little bit in Ple4Win to the next or previous node.

Could you give only a warning in the warning list without the hardcoded error; so no E-number error but a W-number warning and make it possible to use fix nodes.

As a workaround I use little distances between the nodes (small element lengths), where the offset is as small as possible.

A wish to make this possible in Ple4Win.

SWEIGH factors for cast iron ("gietijzer")

Wed, 07 May 2014 11:02:25 +0200

As an addition to the question about SWEIGH factors for PE: If materials have different factors for axial and tangential directions (such as nodular cast iron) then the following should be applied:

The axial factor should be used for SXUB1, SXUBH, SXIOSH and SXIORA,
the tangential factor should be used for SFIOSH and SFIORA,
all other factors should be set to 1.

Out-Of-Plane stress intensification factor for Miter Bends

Sat, 05 Apr 2014 21:54:53 +0200

Hello,

There is some confusion in the attached PDF document. Most important part is given below:

[attachment=543]

According to this document the out-of-plane stress intensification factor ix for miter bends (0.75) is lower then smooth bends (0.9) according to the NEN 3650-1-2003/2012. The document of R&K says says also PLE uses the value for smooth bends which is conservative when the out-of-plane SWEIGH reduction is not used.

The ratio in the out-of-plane stress weighing factors between miter bends and smooth bends is nothing more then the ratio:
SIXcorr_factorr = ix_out_of_plane_miterbends / ix_smooth_bends = 0.75/0.9=0.8333...
According there is a relation between iy and ix, the same corrections should also be applied SIFcorr.

The formulas given in the document for SIXcorr. and SIFcorr. gives some confusion. It is better to say that SXUBH, SFIOSH and SXIOSH should be multiplied with 0.8333... (or =1/1.2).
The user should manually implemend this value in the SWEIGH input table.

Can you confirm this conclusion and if true update this in the helpfile of the upcoming Ple4Win version 4.3.0. So an user can easily search this knowledge in the (online+offline) helpfile.

Thank you.

SWEIGHT factor for PE pipe

Tue, 26 Jun 2012 15:17:51 +0200

Hi,

I have one question about the "SWEIGHT" factor.

According to NEN 3650-3 Table 3, the α_σ is 0.65 for PE 100 pipe, this value is valid for axiale direction and tangential direction as well.

In function 6.2 of Ple4Win 4.2.0, I have to fill in the stress factor for all the components.

SXUB0: stress due to ax. force
SXUB1: stress due to ax. bend. mom.
SXUBH: stree due to higher harm. of bend. mom.
SXIOSH: weighting factor ax. stress (moment)
SFIOSH: weighting factor circ. stress (moment)
SFUBA: weighting factor hoop stress
SFURA: weighting factor circ. normal stress
SXIORA: weighting factor ax. stress (soil)
SFIORA: weighting factor circ. stress (soil)

Does anyone know where to fill the 0.65 exactly? Only the weighting factor columns or all the other columns except the weighting factor for hoop stress?

Warning W610/17

Thu, 15 Mar 2012 10:06:19 +0100

Hello,

I get a warning of implosie (120%) in one calculation in which the intern pressure is present with a load factor 1,15.

However, according to NEN3650-2 Table 2 and 3, for implosion calculation only loadingcombination 1,3,6 is necessary, in which there is no intern pressure.

I think this warning should not present in the calculation with intern pressure, is that correct?

support forces by case study

Wed, 29 Feb 2012 14:36:46 +0100

Case:
See figure below, no top load, between node 890 and node 894 is linked by a "weak"

  case.bmp (Size: 36,39 KB / Downloads: 39)
Aim: To obtain forces and moments at support point muur 2 – node 890 and at point muur 3 – node 891

  SUPREA.bmp (Size: 140,57 KB / Downloads: 39)

  ADDSUP.bmp (Size: 146,32 KB / Downloads: 39)

  CSLOAD.bmp (Size: 165,72 KB / Downloads: 39)

The orientation and value are quite different if i compare these three tables, they are all using locale element coordinate systeem, which value is actually the force and moment at the support punt?

Soil settlement and pipeline displacement

Fri, 10 Feb 2012 13:22:48 +0100

Dear Mr./Mrs.
I am now calculating the maximum settlement value for specific pipes. The assumption is simple, a straight pipe with infinite open model boundary, in the middle of the pipe, there is a double shape settlement loading. The aim is to find the maximum tolerant value.

  example.bmp (Size: 175,83 KB / Downloads: 45)
Background
According to paragraph 4.5 in the “theoretical manual” published in 1989 march, version 3.02, the resulting soil reaction will be where
- K represents the soil stiffness
- ∆S is the movement of the soil, input SUBZMAX in function 4.2
- ∆P is the distance with which the pipeline move together with the soil movement, output U-Z in function 5
And there will be two cases,
- the pipe follows the soil settlement completely, ∆P=∆S, then U-Z=SUBZMAX
- the pipe is rigid, ∆P<∆S, then U-Z Example
Pipe: DN800 water pipe with a wall thickness 9.52mm
Loading: pressure 5 bar and the settlement (-44mm, uncertainty factor 2)
From the calculation results, the input subsidence length has a large influence to the stress, see pictures below, the blue colour is SUBZMAX and the pink colour is U-Z.

  6m_1.gif (Size: 29,15 KB / Downloads: 37)

  12m_1.gif (Size: 29,82 KB / Downloads: 37)

  24m_1.gif (Size: 28,36 KB / Downloads: 37)
//pictures resized by moderator//
Questions
- In the third case with a 24 m length, why the U-Z could be larger than the SUBZMAX? The pipe could either completely follow the soil or rigid enough move less than de soil. What is the physical meaning if ∆P>∆S?
- If the input length follows NEN-3650, in this case, would be 20 m. Then the maximum settlement is larger than case 1 and case 2, which will show the similar shape as the length is 24 m. How could you determine an optimum length for specific pipe?

45 degree connections

Thu, 22 Dec 2011 10:52:51 +0100

Dear Mr./Mrs.
I have two questions about connections.
We are now busy with a project which has a lot of 45 degree reinforced connections. After reading the document of “T-stukken in PLE-micro-CAD” rev.7 d.d.1-11-2002, it is possible to do it for the configuration.
But according to the explanation, in the T-module it is combined with Stress intensification factor (SIF) of in and out-plane

  1.bmp (Size: 20,33 KB / Downloads: 117)
In the Tee

  2.bmp (Size: 60,62 KB / Downloads: 118)
However, without T-module we have to input the SXUB1 factor in table CSWEIGH. From what I understand is that
• If PHI-MB is 90 or 270 degree, then Mbi=0, MBEN=Mbo. In this case SXUB1=SIX-OP
• If PHI-MB is 180 or 360 degree, then Mbo=0, MBEN=Mbi. In this case SXUB1=SIX-IP
Question 1:
If PHI-MB is not the case above, how could I combine SIX-OP and SIX-IP to SXUB1?
Question 2:
What is the Stress intensification factor for 45 degree?

  tee.PNG (Size: 30,69 KB / Downloads: 128)

No supports possible in inclined parts of the pipeline

Tue, 19 Jul 2011 22:30:02 +0200

When you have a support in the inclined part of the pipeline (with an angle let say for example 30 degrees) an error will occur. Ple4Win doesn't allow supports in the inclined parts with high angles. The function will be stopped.

This warning will be given:

[attachment=194]

Why do you give this error?

Theoretically it is possible to calculate support forces in an inclined part of a beam.

Stiffenring/Verstijvingsring

Tue, 24 Nov 2009 10:05:49 +0100

How should a stiffnessring be inputted in the model , without having problems concerning the diameter/wallthickness ratio?

I tried the following method without result:

Use a element with a length equal to the width of the ring.
Wallthickness (t) in this element is equal to body-radius of the ring.
Diameter (D) is equal to the outer diameter of the ring.

This configuration give the folowing error: "diameter/wallthickness-ratio to large". This is an clear error, because a pipeline with these values will not behave like a thinwalled construction.