Quantifying Time Dependent Viscoelastic Deformation during Coordinate Metrology Audits
Unmanaged viscoelastic creep under metrology clamping fixtures consumes up to forty percent of engineering tolerances, requiring documented dwell periods.
Hysteresis Decay
Meaning
Progressive reduction in the energy dissipated by a material during successive cycles of loading and unloading. This phenomenon indicates a stabilization of the internal structure as the polymer chains or microscopic components reorganize. It marks the transition from the initial virgin state of the material to a steady state of cyclic operation.
Cycle Stabilization
Internal friction decreases after the first few applications of force. The presence of hysteresis decay is most visible in the narrowing of the area between the loading and unloading curves on a stress-strain plot.
Material Softening
Changes in the modulus occur as the material is exercised. While hysteresis decay is often expected, excessive softening can compromise the functional stiffness of a component.
Operational Readiness
Components intended for vibration damping or seals must reach a stable state before their performance is audited. If hysteresis decay is still active during final testing, the measurement results will not reflect the long-term behavior of the part. Production protocols often include a break-in period to ensure the product meets the demonstrated rate of performance before it leaves the plant.
This prevents the cost of early field failures caused by changing part dimensions and ensures the reliability of the assembly.