Forum has been restored

After the website hack we endured in 2018 our first priority was to restore the website. After that, the forum was addressed, but restoration (including full content, thread numbering, internal links etc.) proved to be much more complicated than expected.

But now the Ple4Win forum has been restored. Credentials for forum users also have been restored, so the forum can be used immediately by former users without the need to re-register. As a safety precaution we advise all users to change their login password manually after the first login.

To visit the forum, please follow this link.

ir. Gerard Kruisman (1936 – 2018)

Met veel verdriet maken wij bekend dat op woensdag, 12 september 2018 ir. Gerard Kruisman is overleden, de oprichter van r+k Consulting Engineers, onze inspirator en motivator.

Gerard Kruisman, civiel ingenieur, Ridder in de Orde van Oranje-Nassau, is rustig ingeslapen na een periode van afnemende gezondheid. Hij is 82 jaar oud geworden.


Hij was tot het laatst actief betrokken bij ons bedrijf. Wij van Expert Design Systems en r+k Consulting Engineers zullen zijn unieke stijl van leiden, zijn visies en ideeën missen.

Wij gaan vol vertrouwen het werk voortzetten dat hij opgestart heeft. Hij zal door zijn collegae zeer gemist worden.



It is with deep sorrow that we inform you of the death of the founder of r+k Consulting Engineers, our inspirator and motivator, Gerard Kruisman MSc on Wednesday, September 12, 2018.

Gerard Kruisman, Master of Civil Engineering, Knight in the Order of Orange-Nassau, passed away peacefully in his sleep after a period of illness. He was 82 years old.


Up until very recently, he was actively participating with our company. We at Expert Design Systems and r+k Consulting Engineers will miss his unique way of leadership, his visions and ideas.

We have full confidence to continue the work he once started. He will be severely missed by his colleagues.


Restoring website after hack

This website and the website of our sister company r+k Consulting Engineers have been hacked recently. Our apologies for that.

We are in the process of restoring both websites. While this is happening, some parts of the website such as the forum can be offline. Please be patient, we will restore functionality as soon as possible.

As the websites are hosted separately and no personal information is asked or stored (even the e-mail addresses for download are not retained) there has been no data breach, no personal identification information could have been obtained by the hackers.

Ple4Win 4.5.0 updated

After releasing version 4.5.0 some bugs in the calculation core have been discovered that influence the calculation of mitre bends.

We updated (patched) the program to correct these, see the change log for more details.

If you use the mitre bends functionality (I module) please only use the patched version of the program. In all other cases we still encourage users to un-install the original version 4.5.0 and install the updated version afterwards, but it is not strictly necessary.

PleEdu4Win 4.5.0 released

The educational PleEdu4Win version 4.5.0 has been released. This version contains all improvements, modifications and adaptations of the professional Ple4Win version 4.5.0, where applicable. As with previous educational versions, this program can be downloaded and used freely to gain a good insight into what the Ple4Win program can do.

Download Ple4Win Educational 4.5.0.

The main highlights of the new release are:

Data entry

  • In the POLYDIF table, not required fields are disabled from editing.


  • Modernised the look of the application;
  • Additional idents automatically placed when pipe crosses the ground or water level;
  • Animated, explicit indication when the status of the Warning table changes.

Ple4Win 4.5.0 released

Ple4Win version 4.5.0 has been released. A newly developed mitre bends module has been incorporated in this version. Furthermore, the looks of the program have been modernized. Also, this version contains a number of other improvements, modifications and adaptations. For a detailed description of all that is new and changed, please see the change log.

Summarised, the key highlights of the new release are:

  • A new Mitre bends module.
  • Changes to the graphical user interface.
  • New functionality in input table ‘Pipeline polygon points’ / POLYDIF.
  • Added graph showing the material’s stress-strain relation.
  • And more

Mitre bends

  • Easily configure a mitre bend using only two extra parameters.
  • Calculations according to NEN 3650 or TGSL 1986.
  • No further user actions required!

New functionality in table POLYDIF

  • Configure a mitre bend by parameters N-KINK and L-SEGM.
  • Not required fields are disabled from editing.

Some other improvements

  • Additional idents automatically placed when pipe crosses the ground or water level.
  • Animated, explicit indication when the status of the Warning table changes.

Courses for Ple4Win users

The performance, accuracy and speed of a project calculated using Ple4Win depends for not a small part on how the project is modeled. More often than not, a good pipeline model has greater benefits than e.g. a faster computer and may prevent lots of calculations on model variations. We are providing for a course on the art of making a good functional pipeline model. This half-day course is primarily intended for experienced users.

For more detailed information, call +31 (0)70 390 2386 or mail to

We also offer courses for inexperienced users and dedicated training for individuals or small groups, focused on specified wishes of the attendees and/or going into details of specific problems the attendees have encountered. The combination of a course together with a project to be calculated is also possible. Again, contact us for more information.

Ple4Win forum

For support or advice, please visit the Ple4Win forum. There you can also read the FAQs, tips & tricks, report your findings or tell us your views.

Large Deflections of Buckled Bars

This post is the first of a new category of application scope examples for Ple4Win. The emphasis of these examples is using the program ‘beyond the box’. See the starting page for more information.

Large Deflections of Buckled Bars

Consider a slender rod, as shown in figure 1. It is fixed at the base, free at the upper end.

Figure 1: Vertical bar, fixed at the base.

If a load P is applied that is somewhat larger than the critical value described by Euler’s Column Formula:


then a large deflection of the bar is produced. As described in Timoshenko & Gere’s “Theory of elastic stability” (chapter 2.7 “Large deflections of buckled bars (The Elastica)”) the relation between applied load and deflection can be described using the formula:


With Ple4Win, it is possible to calculate this beam deflection behaviour. Figure 2 shows the calculated bar deflections at different ratio’s P / Pcr

Figure 2: Deflections of a vertical bar at different ratio’s P / Pcr,

Note that the “non-linear geometry model” option must be used as well as the “linear material model” option. As the theory does not take compression effects or the influence of shear force into account, the material parameters in Ple4Win must be adapted to minimise their influence (these effects can not be switched off in Ple4Win).

Figure 3 shows a comparison between vertical and horizontal deflections as calculated by the program and as mentioned in the book by Timoshenko & Gere. The deviations are less than 2% for an angle  of 20° (compression effects) and between 0.1% and 0.5% for angles of 40° and higher.

Figure 3: Comparison between theoretical calculations and results obtained from Ple4Win.

50 years Ple4Win anniversary

On October 1, 2015, we celebrated the 50th anniversary of Ple4Win, more specifically that 50 years ago the necessity arose to calculate the behaviour of buried pipelines in soft soils.



Meeting at the historical fortress Wierickerschans, a presentation was given about the difficulties the Dutch Gasunie encountered when they wanted to cross the nearby Dubbele Wiericke with a 36″ high-pressure gas pipeline in 1965.


The construction finally used was too conservative (and too expensive!) for all practical purposes, but almost nothing was known about pipe-soil interaction then. So the necessity to explore the behaviour of buried pipelines was pressing, and this was the starting point for developments that finally led to the Ple4Win program of today.