Seismic Spectral Acceleration Calculator
Read independently verified damping/site/edition-matched seismic acceleration spectrum over sampled periods. Independently matched piecewise-linear calibration, no extrapolation. Caller independently establishes units, regime, calibration and applicability; this does not establish design-code compliance, authenticity, operational safety, treatment efficacy or a validated forecast.
Description
A seismic response spectrum requires a location, model and adopted design basis.
A seismic response spectrum requires a location, model and adopted design basis.1
Interpolating caller data does not retrieve a hazard map or install a code spectrum. Use this tool to interpolate the supplied calibration and inspect its local slope.
When to use Seismic Spectral Acceleration Calculator
Use this tool to interpolate the supplied calibration and inspect its local slope. Establish the SI units or caller unit basis, load signs, measurement interval, model conditions and independently chosen coefficients or references.
How to use Seismic Spectral Acceleration Calculator and understand its results
- Establish the SI units or caller unit basis, load signs, measurement interval, model conditions and independently chosen coefficients or references.
- Enter observedSeismicPeriodCoordinates, callerVerifiedSeismicPeriodResponses, querySeismicPeriodCoordinate, using the field meanings and rules below, then run the tool.
- Read interpolatedMatchedResponse, localObservedSlope. Interpret the fields using their units, signs and evidence conventions below.
- If input validation fails, correct the reported field and run again. Before applying the result, check reference scope, model assumptions and any missing evidence or placeholder values.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| observedSeismicPeriodCoordinates | Observed seismic period coordinates | list of number | Required |
| callerVerifiedSeismicPeriodResponses | Caller verified seismic period responses; caller assertion or measurement requiring independent evidence | list of number | Required |
| querySeismicPeriodCoordinate | Query seismic period coordinate | number | Required |
Enter at least two aligned finite calibration coordinates and responses. Coordinates must be strictly increasing, and the query must be within the first and last coordinates, including endpoints. Interpolate the response linearly on its enclosing segment and return the response plus that segment's slope. At an internal knot the slope uses the segment to its right; at the last knot it uses the last segment. There is no extrapolation, curve fitting or built-in calibration, and response knots need not be monotonic. Independently establish coordinate and response units and applicable calibration scope.
y(q)=y_j+(q−x_j)×(y_(j+1)−y_j)/(x_(j+1)−x_j); localSlope=(y_(j+1)−y_j)/(x_(j+1)−x_j) Use the exact units, boundary rules, ordering and missing-evidence conventions above.
| Output field | Meaning | Value type |
|---|---|---|
| interpolatedMatchedResponse | Piecewise-linear response in the caller calibration unit | number |
| localObservedSlope | Enclosing segment response change per coordinate unit, using the knot-side convention above | number |
{
"input": {
"observedSeismicPeriodCoordinates": [
1,
2,
3
],
"callerVerifiedSeismicPeriodResponses": [
2,
4,
8
],
"querySeismicPeriodCoordinate": 2.5
},
"output": {
"interpolatedMatchedResponse": 6,
"localObservedSlope": 4
}
}Limitations and assumptions
Results are confined to the supplied calibration interval. The tool does not establish a valid physical calibration, propagate measurement uncertainty or guarantee that linear segments represent the underlying process.
All listed fields require explicit values. Unexpected fields, incorrect types, nonfinite numbers and sparse evidence arrays fail validation; the specific bounds and alignment requirements are stated above. Extremely large inputs or outputs can also be rejected. An input error is distinct from a successful result reporting false, no matches or missing evidence.
Alternative or Complementary methods
Use Nyquist Stability Calculator for this related task: A Nyquist polygon's winding about minus one connects contour geometry with a declared open-loop pole count.
Use Root Locus Breakaway Calculator when its separate inputs and assumptions fit the question: A real root-locus stationary point satisfies a logarithmic gain-derivative condition.
References
-
Seismic Spectral Acceleration Calculator — tool.io
Similar or alternative tools
- Nyquist Stability Calculator
A Nyquist polygon's winding about minus one connects contour geometry with a declared open-loop pole count.
- Root Locus Breakaway Calculator
A real root-locus stationary point satisfies a logarithmic gain-derivative condition.