Performance Polymers
Ultrasim® Integrative Simulation
Integrative Simulation Capabilities for Engineering Plastics
Engineering plastics are reinforced with fibers to increase stiffness. The material stiffness varies depending on the fiber alignment. If the fibers are aligned in the force direction, the stiffness will be much higher compared to transversal oriented fibers. During the mold filling process, the fibers will align in the part according to the filling pattern. These effects thus lead to anisotropic (= directionally dependent) stiffness and strength all over the part.
The integrative method realized within Ultrasim® takes those effects into account. A preceding filling simulation supplies the spatial fiber orientation which is mapped (= transferred) to the mechanical Finite-Element-model of the part. Our comprehensive material models use the local fiber orientation and precisely describe the part behavior under static service loads, in vibration modes or in a crash event.
Integrative Simulation Capabilities for Structural Foams
The density of a foam has a big impact on its physical properties like its thermal conductivity or mechanical stiffness. In parts made of reactive polyurethane foams, the density field evolves heterogeneously during the foaming process. The blowing reaction is dependent on the local temperature which itself is not constant throughout the part. The density typically decreases with the flow length. At the flow front the foam can expand freely, whereas close to the injection point the expanding foam must work against the pressure that is built up in the mold leading to less expansion.
The integrative simulation approach makes it possible to account for these density variations in a structural part simulation. To this end, a preceding simulation of the reactive foaming process is performed. The latter simulation provides the density field as a result which can be “mapped” to the structural mesh and then be used locally by the density dependent Ultrasim® foam material model.