Eurocode 8 - Raw functions¶
Chapter 3¶
seismic_action¶
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streng.codes.eurocodes.ec8.raw.ch3.seismic_action.spectra.
S
(ground_type, spectrum_type)[source]¶ Parameters: Returns: soil factor
Return type:
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streng.codes.eurocodes.ec8.raw.ch3.seismic_action.spectra.
SDe
(T, Se)[source]¶ Parameters: Returns: The elastic displacement response spectrum. Given using the expression:
\[S_{De}=S_e(T)\cdot(\dfrac{T}{2π})^2\]Return type:
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streng.codes.eurocodes.ec8.raw.ch3.seismic_action.spectra.
Sd
(T, αg, S, TB, TC, TD, q, β=0.2)[source]¶ Parameters: - T (float) – The vibration period of a linear single-degree-of-freedom system
- αg (float) – The design ground acceleration on type A ground (ag = γI*agR)
- S (float) – The soil factor
- TB (float) – The lower limit of the period of the constant spectral acceleration branch
- TC (float) – The upper limit of the period of the constant spectral acceleration branch
- TD (float) – The value defining the beginning of the constant displacement response range of the spectrum
- q (float) – The behaviour factor
- β (float) – The lower bound factor for the horizontal design spectrum. Recommended value for β is 0.2
Returns: Design spectrum for elastic analysis. Given using the expressions:
\begin{eqnarray} 0 \le T \le T_B \rightarrow & S_d(T) & = α_g\cdot S \cdot (\dfrac{2}{3}+\dfrac{T}{T_B}\cdot(\dfrac{2.5}{q} - \dfrac{2}{3})) \\ T_B \le T \le T_C \rightarrow & S_d(T) & = α_g\cdot S \cdot \dfrac{2.5}{q} \\ T_C \le T \le T_D \rightarrow & S_d(T) & = α_g\cdot S \cdot \dfrac{2.5}{q} \cdot \dfrac{T_C}{T} \ge β \cdot α_g \\ T_D \le T \le 4s \rightarrow & S_d(T) & = α_g\cdot S \cdot \dfrac{2.5}{q} \cdot \dfrac{T_C\cdot T_D}{T^2} \ge β \cdot α_g \end{eqnarray}Return type:
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streng.codes.eurocodes.ec8.raw.ch3.seismic_action.spectra.
Se
(T, αg, S, TB, TC, TD, η=1.0)[source]¶ Parameters: - T (float) – The vibration period of a linear single-degree-of-freedom system
- αg (float) – The design ground acceleration on type A ground (ag = γI*agR)
- S (float) – The soil factor
- TB (float) – The lower limit of the period of the constant spectral acceleration branch
- TC (float) – The upper limit of the period of the constant spectral acceleration branch
- TD (float) – The value defining the beginning of the constant displacement response range of the spectrum
- η (float) – The damping correction factor with a reference value of η = 1 for 5% viscous damping
Returns: The elastic acceleration response spectrum. Given using the expressions:
\begin{eqnarray} 0 \le T \le T_B \rightarrow & S_e(T) & = α_g\cdot S \cdot (1+\dfrac{T}{T_B}\cdot(η\cdot 2.5 -1)) \\ T_B \le T \le T_C \rightarrow & S_e(T) & = α_g\cdot S \cdot η\cdot 2.5 \\ T_C \le T \le T_D \rightarrow & S_e(T) & = α_g\cdot S \cdot η\cdot 2.5\cdot \dfrac{T_C}{T} \\ T_D \le T \le 4s \rightarrow & S_e(T) & = α_g\cdot S \cdot η\cdot 2.5\cdot \dfrac{T_C\cdot T_D}{T^2} \end{eqnarray}Return type:
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streng.codes.eurocodes.ec8.raw.ch3.seismic_action.spectra.
TB
(ground_type, spectrum_type)[source]¶ Parameters: Returns: The lower limit of the period of the constant spectral acceleration branch
Return type:
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streng.codes.eurocodes.ec8.raw.ch3.seismic_action.spectra.
TC
(ground_type, spectrum_type)[source]¶ Parameters: Returns: The upper limit of the period of the constant spectral acceleration branch
Return type:
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streng.codes.eurocodes.ec8.raw.ch3.seismic_action.spectra.
TD
(ground_type, spectrum_type, national_annex='default')[source]¶ Parameters: Returns: The value defining the beginning of the constant displacement response range of the spectrum
Return type:
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streng.codes.eurocodes.ec8.raw.ch3.seismic_action.spectra.
dg
(αg, S, TC, TD)[source]¶ Parameters: Returns: Design ground displacement. Given using the expression:
\[d_{g}=0.025\cdot α_g \cdot S \cdot T_C \cdot T_D\]Return type: