Meaning
Scalar quantities represent the work stored within a deformed mesh element when external loads or thermal contractions cause internal displacement. In the context of polymer simulation, finite element strain energy quantifies the potential energy accumulated as a part cools and shrinks within a mould. High levels of this energy often indicate regions where the material is under internal stress.
Calculation Method
Numerical solvers integrate the product of stress and strain across the volume of each discrete element in the model. This finite element strain energy calculation identifies areas where the geometry resists natural contraction. Elements located near stiff ribs or thick bosses typically show higher values than those in thin, uniform walls.
Warpage Prediction
Ejection of the part from the cavity releases the stored forces, leading to the physical distortion commonly seen in semi-crystalline resins. Monitoring the distribution of finite element strain energy allows engineers to predict which direction the part will bow or twist. Steep gradients of energy across a surface suggest a risk of sudden snapping or long-term creep failure.
Mesh Sensitivity
Fine meshes provide a more granular view of the energy distribution but require greater computational resources. Strategic use of finite element strain energy helps in optimizing gate locations to balance the cooling rates across the tool.
