Welcome to Fibersim 101, a step-by-step series of articles meant to familiarize new users with the key concepts of the software. We recommend starting with Part 1 here and downloading the “Fibersim_101.zip” file at the bottom of the page in order to follow along with these exercises.”
Fibersim stores all design information, including ply shapes, material types, and laminate stackup information, inside the CAD model. This data is organized in a hierarchical manner, where the top-level object is known as a Laminate.
A laminate is an organizational tool for grouping and sequencing plies, cores, and additional laminates. It is also used to define the layup surface and overall part boundary. Laminates contain various pieces of information such as sequence, step, and part numbers.
A laminate can be viewed as an assembly of composite objects. Just as any mechanical assembly can contain several subassemblies, a Fibersim laminate may contain several sub-laminates, also known as child laminates. Such grouping is maintained by the concept of “sequencing”, the order in which these components are laid up.
Similarly, plies and cores are created as “children” of a parent laminate. When a laminate is defined, its characteristics, such as layup surface and boundary, can be shared by all child components.
Simple parts may be defined accurately using only a top-level laminate. Other parts, incorporating cores or inserts, for example, may require child Laminates to represent the significant change in layup surface caused by the addition of such objects. Complex parts containing Ply packs and/or subassemblies may require several laminates to be accurately represented.
At a minimum: laminates must be defined using a 3D layup surface and 3D boundary, representing the overall shape of the finished part. Sequence and step values specify each laminate’s order in the composite part stackup.
For every composite part designed, at least one laminate must be fully defined.
A fully defined laminate is one that has a surface and boundary associated to it, and has been assigned sequence and step values giving it the correct order in the composite part stackup.
Because the laminate serves two major purposes (surface definition and component grouping), there are two major reasons for defining additional laminates in a composite design: to represent changes in surface topology, and to represent logical groups of components (i.e. Subassemblies or Ply Packs)
When the layup surface topology of the composite part stackup changes significantly (due to ply material build-up or core insertion), a new surface should be defined so that Fibersim can generate accurate flat patterns and laser projection data. A new laminate is created as a child of the top-level laminate, the new layup surface is associated to this child laminate, and plies laid on this new surface are created as children of the child laminate.
Further, child laminates can represent subassemblies that are manufactured separately, or simply to organize logical groups of components. If no surface or boundary is defined for a child laminate, the surface and boundary of the parent laminate are inherited automatically.
Child laminates can aid in ply definition. For instance, if several smaller plies of similar shape are to be laid in a particular area, it may be useful to assign these plies to a child laminate, whose boundary represents overall shape of this smaller area. Since each ply inherits the outer boundary of its parent laminate, this greatly reduces the time and effort required to define plies.