What this calculator does
It calculates the modeled life ratio caused by increasing a positive stress under an inverse power relationship, then converts a target use exposure to its accelerated equivalent.
When to use it
Use it only when evidence supports life proportional to stress raised to a negative power for the mechanism of interest. Depending on the application, stress may be voltage, pressure, mechanical load, vibration, or another consistently measured quantity.
Inputs and formula
Use and test stress must share the same unit, test stress must be higher, and the positive exponent must come from appropriate data or technical evidence.
Life = A × stress−nAF = (stresstest / stressuse)nWorked example and interpretation
For use stress 5, test stress 10, exponent 3, and 10,000 target exposure units, AF is 8 and equivalent accelerated exposure is 1,250 in the same time or cycle unit.
Practical notes and limitations
The exponent can change with design, mechanism, and stress range. Do not cross material limits or extrapolate across thresholds, yielding, breakdown, or a new failure mechanism. The tool does not fit the exponent or a life distribution and provides no uncertainty estimate.