Topology Concept

In cases when models have dependencies, these shall be saved as references to objects or part of objects. Such references constitute the topology of the model.

Each design model object holds references to the objects that are part of its definition, for example the surfaces, curves or panels defining a plane panel boundary. Thus, each object can be regenerated using its references. This might create a new instance with for example an updated outer contour if the referred objects have changed its position or shape.

The model can also extract and present depending objects, for example a deck will know about all the webs that are attached to it.

To benefit from the topology, it is essential that it is well defined. This means for example that a bulkhead that ends at a deck should have a limit definition that is a model reference. Preferable this reference should be as generic as possible. A reference to the deck surface is a better reference (from a topological perspective) than referencing the deck panel and referencing the deck panel is a better reference than referencing a grid plan. In any case, absolute coordinates should be avoided. When the referencing is to the underlying surface or the deck panel, a recreated bulkhead would then pick up location and shape changes of the deck as well as thickness compensate for the plate thickness in the deck plates.

Circular references should be avoided. If for example two deck panels are connected, they should not refer each other directly, but rather reference a polyface representing for example a block limit.

Many references are on component level, for example a bracket referring a stiffener on the same panel or on another panel. If the boundary definition of a bulkhead refers a deck and then a stiffener on that deck refer a stiffener on the bulkhead this may seem like a circular reference as the bulkhead refers the deck and vice versa. It is not as the topology must be viewed on component level. Thus, the boundary of the bulkhead is dependent on the deck position and plating while the deck stiffener is dependent on the bulkhead stiffener. So, it is quite possible to sort out for example in which order to regenerate the components of the panels.