Finite Element Virtual Unclamping Formulation for Anisotropic Polymer Moldings
Virtual unclamping maps fixture-constrained inspection scans to free-state polymer geometry through anisotropic stiffness tensors and structural springback calculations.
Thermal Residual Stress
Meaning
Internal mechanical tensions remain locked within a metallic component after the rapid, uneven cooling of a manufacturing melt pool. This thermal residual stress can cause the part to warp or crack during subsequent machining or service. Measuring these internal forces allows engineers to adjust the manufacturing parameters to improve the long-term durability of the component.
Solidification Gradient
The high heat from the laser melts the metal powder, which then cools down quickly as the laser moves away. This rapid cooling creates temperature differences across the part, leading to uneven shrinkage. This shrinkage is what creates the internal tension.
Microstructure Deformation
Internal forces can change the metal’s structure, making it weaker and more likely to fail under load. Engineers use X-ray diffraction to scan the part and measure these changes without damaging the component. This testing helps identify weak spots before the part is used in a machine.
Stress Relief
Heating the finished metal part in a furnace is the standard way to release these locked-in forces and make it stronger. The part is held at a high temperature for several hours before being cooled down very slowly to prevent new stresses from forming. This heat treatment is necessary to ensure the part meets the required safety standards for aerospace or automotive use.
Skipping this step to save time can lead to catastrophic failure when the component is put under stress.