Seismic Demands in Nonstructural Components (ASCE 7)

This calc determines nonstructural component seismic design forces per ASCE 7

Input:

lb
g
ft
ft
nonstructural components

Output:

  1. Definitions
    • Fp = Horizontal seismic design force applied at the center of gravity
    • Wp = Component weight
    • SDS = Design spectral acceleration at short periods (0.2sec)
    • Ip = Component importance factor (1.0 or 1.5)
    • z = Height from the point of attachment to the seismic base
    • h = average roof height of the structure with respect to the seismic base
  2. Lookup the component parameters
    • Component = Custom
    • Amplification factor: ap = 1
    • Response modification factor: Rp = 1
    • Overstrength factor: Ω0 = 1 (for anchorage design in concrete or masonry)
  3. Calculate the horizontal design force, Fp
    • Fp = 0.4 ap SDS Wp (1 + 2 z/h) / (Rp/Ip)
    • Fp = 0.4 (1) (0.85) (250) (1 + 2 (0)/(30)) / (1/1)
    • Fp = 85 lb
  4. Calculate the minimum and maximum force limits
    • Fp,max = 1.6 SDS Ip Wp = 340 lb
    • Fp,min = 0.3 SDS Ip Wp = 63.8 lb
  5. Result
    • Fp = max[Fp,min, min(Fp, Fp,max)]
    • Fp = 85 lb

Notes: