An explicit is solved by calculating results in small time increments or time steps. The size of the time step depends
on many factors but is automatically calculated by Radioss.
Composite materials consist of two or more materials combined each other. Most composites consist
of two materials, binder (matrix) and reinforcement. Reinforcements come in three forms, particulate,
discontinuous fiber, and continuous fiber.
An "AIRBAG1" time step is estimated into the Engine, but this time step will never control the time
step during the run. If that is the case, it means there is a non-physical airbag definition in the
input deck.
Optimization in Radioss was introduced in version 13.0. It is implemented by invoking the optimization capabilities of
OptiStruct and simultaneously using the Radioss solver for analysis.
You may define an orthogonal frame (O,
V1,
V2, and
V3), a bounding-box of the
airbag fabric to be mesh defined by the lengths
(L1,
L2, and
L3) and the number of
cutting-step for each direction
(N1,
N2, and
N3).
The cutting width is then given by:(1)
Figure 1 shows a two-dimensional case of how
the airbag fabric is cut:
The automatic meshing procedure is also required if the set of user-defined solids
(Ibric) does not entirely fill the internal volume of the
airbag.
For example, in a case of a folded airbag with a right choice for the cutting
direction V1 and V2, meshing may be sufficient:
In cases where the injector is modeled with an initial rigid volume (canister), using
only two cutting direction (V1 and V3) gives a coarser mesh.
In this example, it may be greater to use the third cutting direction (V2) to reach
the following mesh: