shakelib.conversions.imt.newmark_hall_1982¶
- class shakelib.conversions.imt.newmark_hall_1982.NewmarkHall1982[source]¶
Bases:
IMTConverter
Class for conversion between PGA and PSA10 by Newmark and Hall (1982).
PSA10 stands for spectral acceleration with oscillator period of 1.0 sec
PGV is peak ground velocity.
The conversion factor is 37.27*2.54. Note that 2.54 is the conversion factor to convert from cm/s to in/s and 37.27 is derived from SA(f) = 1.65*(2*pi*V*f)/386.09, where:
SA(f) is spectral acceleration at frequency f (in g)
f is the frequency of interest
V is the velocity
1.65 is the N&H amplification factor for velocity at 5% damping
386.09 is the acceleration of gravity in inches per second per g
The sigma factor was computed from an average sigma value determined by plotting PGV/PSA10 versus Distance for earthquakes with magnitudes greater than or equal to 5.0.
References
Newmark, N. M., & Hall, W. J. (1982). Earthquake spectra and design. Earthquake Engineering Research Institute, El Cerrito, California.
- convertAmps(imt_in, imt_out, imt)[source]¶
Returns an array of converted IMT amplitude values.
- Parameters:
- Returns:
Numpy array of amps converted from imt_in to imt_out.
- Return type:
array
- Raises:
ValueError – If not a valid conversion.