RTM-Worx Composite Material Resin Transfer Molding Process Simulation Expert System

 

RTM-Worx is an advanced resin injection molding process simulation software developed by the Netherlands Organization for Applied Scientific Research (TNO) in 1991. It is widely used to simulate the filling and flow of resin in composite material processes such as RTM and VIP, and can also be used to simulate the general flow process in porous media driven by pressure. RTM-Worx can efficiently and conveniently use finite element method (FEM) and control volume method (CVM) to solve the physical equations of resin flow process in porous media.

 

The software design of RTM-Worx places great emphasis on efficiency, reliability and stability. The numerical accuracy of the software is very high. Even under the worst conditions, only about 150 units are needed to reduce the error to less than 1%. RTM-Worx is little affected by the shape and size of the unit, and the software provides reasonable default values ​​for all necessary data.

 

Since FEM or CVM uses the same discreteness, the convergence of the calculation process and the accuracy of pressure calculation are guaranteed in any case, as well as the certainty of the resin flow front. At the same time, it can predict dry spots, filling time, fluid front, flow rate, resin thickness, filling rate, pressure distribution, permeability, permeation direction, etc.

 

RTM-Worx provides a variety of unit types, including 1D line unit (pipeline), 3D shell unit (space shell structure) and 3D solid unit. The three unit types can be coupled and calculated in the same model, and different permeabilities can be set. This is the industry’s exclusive model calculation capability, which makes it easy to establish extremely complex circulation pipelines.

 

Calculate the material Darcy flow, Poiseuille flow and Hull-Shaw model to calculate the resin flow state. Directly establish injection ports or exhaust ports through points, and establish pipelines and flow channels through lines, and can include porous media or hollow environments.

 

The software has been widely used in aerospace, wind energy, automobiles, civil engineering, shipbuilding and other fields and has a market share of more than 65% in the global RTM simulation application market.

 

 

RTM-Worx Technical Features

 

Friendly Graphical Interface

RTM-Worx operation interface has a typical WINDOWS style, which is simple and easy to use. Models are constructed by importing geometric structures or directly establishing point, line, and surface structures in the software. Attribute information can be directly assigned to geometric entities, which is similar to the concept of finite element analysis unit group but more intelligent, and unit attributes can be arbitrarily specified or changed. It can provide a conceptual model that is more realistic than manual unit groups and is applicable to all geometric bodies.

 

RTM-Worx Operation Interface

 

Highly Integrated Simulation System

 

RTM-Worx is a highly integrated simulation system. The three modules of pre-processor, solver and post-processor are integrated in the same interface, which can independently complete the complete resin injection process analysis and obtain the analysis results. The solver uses the finite element FEM method to construct the unit and the control volume method CVM to calculate the fluid front end to obtain high-precision calculation results. Each analysis module can be switched at will.

 

The software uniquely establishes points (which can simulate injection ports or exhaust ports), 1D line units (which can simulate pipes or flow channels), 2D shell units (simulating shell structures), and 3D solid units (simulating heterogeneous parts) in the same structural model to achieve rapid modeling and analysis of complex shapes and multiple pipes.

 

▪ Powerful and Scalable Composite Material Process Simulation

 

RTM-Worx is designed to simulate the RTM process, but it can also simulate the resin infusion molding process (RIP). The non-isothermal reaction module of the software enables RTM-Worx to be used to simulate the reaction injection molding process (RIM). The software has been widely used in aerospace, wind energy, automotive, civil engineering, shipbuilding and other fields.

 

RTM-Worx uses the CFD-Worx core. CFD-Worx has been widely used in thermoplastic injection molding and gas-assisted molding (GAIM WORX) and chip packaging (3P-Worx) software, and the sharing of the core also facilitates the verification work of RTM-Worx users.

 

▪ Higher calculation stability and efficiency, fast calculation speed and high simulation accuracy

 

RTM-Worx has a completely redesigned interface and faster calculation speed (four times faster than the first RTM process simulation software π7). The solution speed is very fast, and the coarse grid generally completes the calculation in a few minutes. When the speed, temperature and curing information are fully considered, the calculation process is only about twice as long. The numerical accuracy of the software is very high, even in the worst case (point injection with logarithmic pressure drop), only about 150 units are needed to reduce the error to less than 1%.

 

RTM-Wrox is not troubled by the huge difference in permeability and can be simply applied as a physical parameter, whether it is the measured permeability or the resin channel of Poiseuille or Hele-Shaw flow. Due to the use of FEM/CVM algorithm, the calculation accuracy of the resin flow front end is high. For different unit types, Darcy and Poiseuille, Hele-Shaw are used to simulate the flow phenomenon.

 

Calculation aAccuracy and Speed

 

RTM-Worx software integrates a full 3D surface modeling tool. First, enter the node coordinates x, y, and z that define the neutral surface, and then connect the nodes into curves to form the boundary lines of the surface. The surface is composed of a series of closed continuous curves, and also has properties such as thickness and fabric properties.

 

RTM-Worx has a built-in mesh generator that can automatically and quickly mesh curves and surfaces, and supports incremental meshing. The size of the unit determines the accuracy and precision of the flow simulation. By default, the size of the unit is adapted to the node spacing, which is the so-called “hierarchical” mesh. In general, RTM-Worx simulation performance is best when all unit sizes are approximately equal. In addition, the local meshing accuracy of the model can be improved by adding nodes. Users have great flexibility in choosing and can choose the appropriate meshing method according to the actual situation. Even when importing incorrect curves and surfaces, such as self-overlap and boundary intersections, the mesh generator can generate the correct mesh and calculate smoothly.

 

 Rich Software Model Interface

 

RTM-Worx supports the import of files in multiple formats, including:

 

WDX file: RTM-Worx data format, ASCII file containing all RTM-Worx model data. Allows users to customize the generated files, import from other software or export to other RTM analysis software.

 

STL file: 3D Systems’ SLA interface, in binary and ASCII format.

 

Patran Neutral file format (mesh is imported as a surface model).

 

C-mold mesh file (FEM), import mesh and properties as a surface model.

 

Fluent GAMBIT mesh file.

 

AutoCAD DXF file.

 

SEPRAN file (MSH), including connection elements.

 

π7 Model Database (Pi7) file: full support.

 

In addition, it has an extensible module that can import layup files generated by MSC laminate Modeler software (or Anaglyph’s Laminate Tools). Layup files contain information such as model, finite element mesh, ply sequence and fiber orientation. RTM-Worx software can automatically calculate the preform properties based on this information and save it in a separate file.

 

The file imported by RTM-Worx will be merged with the existing model, and the individual parts will be merged into an overall model. RTM-Worx also supports exporting Patran Neutral, DXF format (which can be used to generate injection method diagrams) and Tecplot data file formats.

 

Parameterized SALT Extended Script Function

 

RTM-Worx provides SALT extended function, using C-like language program, users can write their own program to extend the simulation process. SALT program can be opened and edited with Notepad, and run in SALT console. It can be used flexibly especially for complex ply structures.

 

SALT Command Flow Modeling Of Complex Laminated Materials For Wind Turbine Blades