Meaning
Simulation accuracy in mechanical and thermal modeling of polymeric parts depends on the spatial resolution of the digital model. This discretisation parameter, referred to as finite element mesh density, defines the number of nodes and elements used to represent the preform or container geometry. It determines how precisely the software calculates strain distribution, heat transfer, and wall thickness during stretch blow moulding.
Simulation Precision
Regions with high curvature or rapid temperature changes require a high concentration of elements to capture complex gradients. Inadequate finite element mesh density in these zones leads to inaccurate predictions of polymer stretching and material distribution. Conversely, flat areas can utilize a coarser mesh without losing significant structural detail.
This localized refinement prevents false results in critical areas like the bottle base and shoulder.
Computation Expense
Increasing the number of elements throughout the model raises the processing time and memory requirements. A balance must be found between model detail and solver runtime to maintain workflow efficiency. Run times can extend from minutes to hours when the mesh is overly fine.
Convergence Analysis
Determining the optimal element size requires running successive simulations with progressively finer discretization. When the calculated wall thickness and stress values stabilize, the simulation has achieved convergence. This step verifies that the output is independent of the mesh configuration.
