Special Modeling Options: Thermal Stress
Displacement magnitude
of a V6 engine block
2D slice of engine block
showing Von Mises stresses
FLOW-3D's thermal stress model allows you to simulate a larger range of casting processes. During solidification of molten metal, stresses form due to frustrated shrinkage at mold walls and shape irregularities, and due to nonuniform cooling. The thermal stress model predicts the formation of this stress.
The thermal stress model is built upon the elastic stress model, which was available in Version 8.2. What is added is the expansion and contraction of the material due to changes in temperature. During a simulation, regions containing liquid (i.e. where the material temperature is greater than its solidus temperature) are not affected by the model. Once the temperature drops below the solidus temperature, the model is active and the elastic stress is computed incrementally each time step. Regions with rapid cooling (e.g., in narrow channels or near walls) will shrink fastest. In regions that remain in a liquid state, the elastic stress is zero. Furthermore, a yield-stress limit can be defined to specify a limit to the stress at which point the material is allowed to relax. All elastic material properties can be a function of temperature.
The examples given here are from a simulation involving a V-6 engine block. The first image is colored by displacement magnitude. The second image is a 2D slice from the same simulation, showing Von Mises stresses.
To read more about special modeling options, select from the menu at right.
Read more in our
Casting Tech Papers