Meaning
Computational mechanics governs the distribution of forces across two surfaces that touch under mechanical load. Contact stress analysis quantifies the pressure between mating components such as gear teeth, bearings, or mould parting lines. Engineers apply these calculations to ensure the intensity of local deformation stays below the elastic limit of the polymer or metal.
This evaluation identifies where high peak forces cause plastic flow or surface fatigue during normal operation.
Mechanical Interaction
Deformation patterns change when two bodies experience high pressure at their interface. Contact stress analysis determines the precise geometry of the contact area which dictates the local load magnitude. Smaller contact patches result in higher stress concentrations for the same applied force.
Moulders use this insight to adjust gate geometry or wall thickness to prevent localized degradation.
Structural Limit
Materials perform according to specific tolerance thresholds defined during the design phase. Contact stress analysis compares the calculated force density against the yield strength of the resin. Virgin materials typically withstand higher loads than parts containing high concentrations of regrind.
A datasheet value for compressive strength provides a baseline but the actual part geometry creates stress gradients that alter the survival limit of the final component.
Tooling Feedback
Injection moulds experience repeated force cycles that trigger wear at the parting line or ejector pin interfaces. Contact stress analysis informs the selection of steel hardness and surface coatings to resist these repetitive impacts. High stress levels at the tool surface lead to premature flash formation and costly repair cycles.
Precise modelling prevents this tool degradation by optimizing the contact patch area before the first production run begins.
