Concrete pipelines are usually laid using prefabricated segments connected by Socket-spigot connections. These articulated pipelines can be modelled in Ple4Win, the program in these situations will also check the movements and rotations in the joints and warn if leakages or freeze-up’s occur at any connection.

Cast irons pipeline are usually old pipelines, these can be modelled in Ple4Win as articulated pipelines. Ovalisation of the pipelines are calculated, as are stresses in the pipe, both results can be used to check whether the pipe will crack or implode. Furthermore, Ple4Win will check the movements and rotations in the joints and warn if leakages or freeze-up’s (danger of fragments splintering off at the rim) occur at any connection.

Steel pipelines are the core of the program, the first type that was implemented, and the one with the most possibilities. Straight pipes, elastic bended pipes, hot-bended prefabricated bends, everything is possible and can be analysed using general best practice methods or using methods described in several codes and norms.

Upheaval buckling (UHB) is the buckling of a pipeline due to upward movements of the pipeline. Ratcheting is the progressive (upward) movement of a pipeline due to cyclic loading, resulting in expansion and contraction of the pipeline. These two phenomena, UHB and ratcheting, are connected, but not the same. UHB and ratcheting mostly occur in long, almost straight pipelines, both offshore and onshore that undergo temperature fluctuations.

Non-reinforced concrete pipes, while simpler in design, still require thorough geotechnical and structural evaluation, particularly for underground applications. Ple4Win enables modelling and analysis of these systems, including pipe connections and supports. The software provides all necessary input parameters to support structural assessments, ensuring the pipe's performance can be evaluated even without internal reinforcement.

Concrete pipes reinforced with steel rebar are commonly used in underground infrastructure and demand reliable geotechnical and structural analysis. Ple4Win allows for precise modelling of rebar-reinforced concrete pipes, including detailed evaluation of pipe connections and support structures. The software supplies all required input data for structural calculations, making it a complete tool for designing and assessing rebar-reinforced systems.

Underground concrete pipes reinforced with steel plates require both geotechnical and structural analysis to ensure long-term performance. Ple4Win is the tool to perform the necessary detailed geotechnical evaluations including detailed evaluation of pipe connections and support structures. It also provides the needed data for structural analyses of the reinforced system. All essential input parameters for structural assessment can be obtained, and the results can be directly used in structural calculations.

As a finite element program, the main focus of PLE is on each element separately. However, in reality each slice of a pipeline is supported by or supports its neighbouring slices. PLE can take these effects into account by redistributing ovalisations and/or stresses between elements. Especially with point loads or across step-like large changes of a load this approach gives much more realistic results. Similar, other higher order effects can be taken into account at the user’s discretion, such as 2nd order effects in bends or soil around the pipe counter-acting ovalisation of the pipe.

Soil very often does change over longer periods. Especially in situations involving soft soils, geological active areas or man-made disturbances. In Ple4Win a wide variety of causes for soil deformation can be modelled, such as river deltas, earthquakes, landslides and trenching & backfill during installation of the pipeline. The program allows to define soil settlements in three dimensions, subsidences in different shapes, overburden and live loads on top of soil such as traffic loads.

PLE does offer the possibility to also model offshore pipelines and calculate their behaviour. The main addition is that PLE can model wave and current loadings as quasi-static loads on exposed (non-buried) pipeline sections. The sea state considered is 3-dimensional for waves and 2-dimensional for currents. Waves are characterised by height, period, direction, position and type of crest and wave theory. Wave profiles may be long- or short crested and according to Airy (1st order) or Stokes (5th order) theory. A current profile can be specified either as an exponential curve or by a number of profile values over the water depth. The influence of (weight) coatings and marine growth, resulting in increase of the structural pipe diameter, can be taken into account, as well as the dynamic amplification of forces due to vibration of pipe spans and the influence of nearby stream disturbing members, e.g. jacket members.

Free spans are sections of a pipeline that are not supported by either soil or external supports. In such sections vibration of the span may occur due to the cyclic character of a wave or wind load. PLE can identify those sections, which may differ from the initial layout due to vertical movements. In case of offshore pipelines, PLE can calculate the Dynamic Amplification Factors (DAF's) by which the hydrodynamic forces are multiplied. The amplitude of the pipe vibration is a function of the ratio of the wave (forcing) frequency and the natural frequency of the pipeline span. The closer the wave frequency to the natural frequency, the greater the vibration amplitude and the greater the driving resulting load. The Dynamic Amplification Factor represents the influence of the vibration motion on the (statically determined) wave/current loads. PLE can assist in designing the very important damping and support conditions which may reduce the vibration amplitude considerably.

PLE can perform both elastic material and plastic material calculations. With elastic calculations, the relation between strain and stress always remains linear. In case of elasto-plastic calculations the relation between stress and strain is more complex, but basically the stress is limited to an upper value, even if the strain is increasing further. Plastic deformation occurs, which the program will calculate as long as material yielding is limited to localised areas. Otherwise, the program will warn about imminent collapse of the pipeline.

Pipes made from sandwich wall composites such as glass reinforced epoxy (GRE) can be simulated in Ple4Win as well. The program can perform material linear calculations with anisotropic material properties. With this kind of materials, the program can distinguish between the material stiffness modulus in longitudinal and circumferential direction and can distinguish between normal and bending stressing. Also, the Poisson ratio may be differentiated from axial to circumferential stressing and vice versa.

PLE can perform both material linear and material non-linear calculations. With linear calculations, the relation between strain and stress always remains linear. In case of non-linear (or elasto-plastic) calculations the relation between stress and strain is more complex, but basically the stress is limited to an upper value, even if the strain is increasing further. Plastic deformation occurs, which the program will calculate as long as material yielding is limited to localised areas. Otherwise, the program will warn about imminent collapse of the pipeline.

Ple4Win can perform both geometrically linear and geometrically non-linear calculations. The difference is that in the linear domain equilibrium is obtained for the undeformed beam and in case of the non-linear domain it is for the deformed beam. With more than one load acting on a pipeline, the cross-interference between loads is taken into account with geometric non-linear calculations, making the calculations somewhat more complex but resulting in much more realistic outcomes.

Phased calculations allow the initialisation of the pipe/soil structure by means of import of pipeline displacements and soil reactions from another design database containing the results of a previous (construction) phase. Changes to the model, such as adding or removing connections or changing soil values are possible between phases. This allows convenient modelling of complex situations such as pre-tensioning steel-in-steel sections.

PLE is capable of performing alternating yield calculation as described in the norm NEN 3650-2, paragraph D3.4. It is a material-linear calculation giving insight into whether a pipeline might be damaged because deformations introduce material-plastic deformations. The program calculates the alternating yield criterion according to a generally applicable procedure that allows the direction of principal stresses to change between load cases. These alternating yield calculations can also be used as a basis for low cycle fatigue (LCF) calculation outside the program.

Development in ongoing to allow Ple4Win to perform low-cycle fatigue (LCF) checks as well. In basis, these are similar to alternating yield calculations that the program is already capable of. LCF checks are a material-linear calculation giving insight into whether a pipeline might be damaged because deformations repeatedly introduce small material-plastic deformations. These deformations are infrequent and limited in number, it is not a vibration analysis. If correctly analysed, with the correct load cases and check criterions, LCF in pipelines can be managed and service range and or service life of a pipeline can be greatly increased.

A Mitre Bend is prepared by angle cutting and welding pipe ends of the cut pieces, usually resulting in 45° and 90° bends. Mitre bends frequently occur in low pressure pipelines like potable and wastewater lines or as casing in steel-in-steel situations. Ple4Win allows these bends to be calculated with the theory for smooth bends under certain conditions. Two input data are required (number of kinks and either geometric bend radius or length of segments) to enable the program to calculate the equivalent bend radius and therefore the load on these types of bends. Calculation can be done according to TGSL-1986 or according to NEN 3650-1:2020. The limits for the field of application are clearly indicated and based on mitre bend test results as well and pipeline codes.

Pre-insulated steel pipelines are designed with a steel carrier pipe, polyurethane foam insulation and a high density polyethylene (HDPE) jacket. Using the coating definition option of the Ple4Win program this type of pipelines can be defined in the program, and soil-effects of the larger outer diameter compared to the diameter of the load-bearing pipe are taken into account. The program calculates the lateral soil reaction which can be used to determine the load on the polyurethane foam.

Steel-in-Steel (SiS), or Steel-Cased-Pipeline (SCP), sections can be modelled using a special program module. It allows modelling structures where an inner (medium) steel pipe is encased by an outer (casing) steel pipe for either thermal isolation or as an additional safety precaution. The two pipes can be connected by either fixed connections or roller connections. The latter allows axial movements of the inner pipe with respect to the outer pipe. Both trench-laid SiS sections and horizontally directional drilled (HDD) sections can be modelled. Any movement of the outer pipe is automatically transferred to the inner pipe through the rollers and fixed connections. Movements of the inner pipe (e.g. thermal loads or pre-stressing) are transferred to the outer pipe as well.

Glass Reinforced Epoxy pipelines can be modelled in Ple4Win, bending and ovalisation due to external loads are calculated and can be checked afterwards. As the glass fibres introduce a strong non-isotropic material behaviour the usage of the anisotropic material module is necessary, allowing different material properties in circumferential and longitudinal direction.

Polypropyene pipelines can be modelled as straight sections and (elastically) bend curved sections, connections are possible as well. The Ple4Win program calculates all stress components that are necessary to perform safety checks, and calculates ovalisations that need to be verified for long-term stability. Using load cases, also short-term checks such as internal pressure checks can be performed easily.

Polyvinyl chloride pipelines can be modelled as straight sections and (elastically) bend curved sections, prefabricated bends and connections are possible as well. The Ple4Win program calculates all stress components that are necessary to check against, and ovalisations that need to be verified for long-term stability. Using load cases, also short-term checks such as internal pressure checks can be performed easily.

Polyethylene pipelines can be modelled as straight sections, (elastically) bend curved sections and prefabricated bends, connections are possible as well. The Ple4Win program calculates all stress components that are necessary to check, and ovalisations that need to be verified for long-term stability. Using load cases, also short-term checks such as internal pressure checks can be performed easily.

Modern nodular cast iron pipelines behave very much like steel pipelines and can be similarly checked and tested in Ple4Win. These are modelled as articulated pipelines, so additional checks on the joints (leakage, lock-up) are also performed.