PLE is a Computer Aided Design tool for the pipeline design engineer, who has to design and evaluate the strength and stability of buried or partly buried transport pipelines, that have to meet the safety requirements as they are specified in Pipelines Codes and Regulations. The pipeline may be a high or low-pressure transmission pipeline, onland or offshore.
This more detailed, but still confined description of the program, consists of following subsections:
•Coordinate systems used in Ple4Win
•The 3D pipeline axis, defined by means of polygon lines and circular segments at the location of the connecting polygon points
•The Pipe/Soil interaction model that supports and loads the pipeline structure
•The internal loadings on the pipeline structure
•The various optional analysis methods
The detailed description of the various data that together constitute the model and its loadings and the way in which these loadings are combined into loading combinations, is provided in the section 'Design Functions". It shall be kept in mind that due to the highly non-linear character of the soil and in case of large displacements, large ovalisations (in case of occurring material plasticity), the non-linear behaviour of the structure, the loadings cannot be superimposed anymore as is generally done in structural analysis of building structures.
The program Ple4Win is structured in a (greater) number of modules, that provide special options for the pipeline model. The module structure is described and shown in the section Module structure and the modules are described in more detail in that same section.
Support and external loading of the pipeline result from the surrounding soil. The soil model is based on the mechanical properties of the soil, which mainly depend on the displacement direction (upward, sideward, downward and axial) of the pipe relative to the soil.
Based on soil failure mechanics in the four principal directions a 3D soil model is built in such a way that in the model the soil reaction is defined in any direction of the pipeline displacement. The deformation behaviour of the soil is considered to be non-linear elastic or elasto-plastic and primarily based on a bilinear curve. Over the first part of the curve the deformation behaviour of the soil is considered to be linear elastic (constant ratio between soil reaction and pipe displacement), whereas over the second part the soil behaviour is considered to be ideal plastic (constant soil reaction independent of the pipe displacement). Other, smooth, curves can be applied too. Even slacks (for instance in a jacket tube) are possible.
At the end points of the pipeline structure to be taken into account, a free end or rigid support or a connected half-infinite long pipeline can be specified. Along the pipeline axis external linear elastic supports can be specified. For instance a "table" support with friction properties.
Ple4WinProgram, last changed: 9/14/2016