RC Wall — N + My Capacity

1 — Cross-Section Geometry

b = mm Wall thickness (y-direction)

h = mm Wall length in bending plane (z-dir.) — origin at centroid

Gross area A_c

—mm²

Total steel A_s

—mm²

Reinf. ratio ρ_l

—%

2 — Materials & Partial Factors

Concrete

f_ck

γ_C—Table 2.1N

α_cc—§3.1.6

Reinforcement

f_ykMPa

γ_S—Table 2.1N

E_sGPa

Design Strengths

f_cd= α_cc·f_ck/γ_C =—MPa

f_yd= f_yk/γ_S =—MPa

ε_cu2 = 3.50 ‰ · ε_c2 = 2.00 ‰ · n = 2 (Table 3.1, f_ck ≤ 50 MPa)

3 — Applied Forces (ULS)

N_Ed kN Axial force (negative = compression)

M_Ed kNm Bending moment about y-axis (positive = compression at +z face)

4 — Reinforcement Bars — Coordinate Input

Each row = one physical bar. y [mm] = offset in wall thickness direction from centreline (for drawing only — does not affect N–M_y capacity). z [mm] = distance from section centroid along wall length — positive toward compression face (+z). φ [mm] = bar diameter. Maximum 50 bars.

#	y [mm] thickness dir.	z [mm] + = comp. face	φ [mm]	A_s,i [mm²]

5 — Cross-Section Drawing & Summary

Section y–z · red = +z (comp.) · blue = −z (tens.)

#	y [mm]	z [mm]	φ	A_s,i [mm²]

A_s= Σ A_i =—mm²

ρ_l= A_s/(b·h) =—%

6 — N–M_y Interaction Diagram

Design N–M_y envelope · 300 concrete fibre strips · parabolic-rectangular σ–ε (EC2 §3.1.5) · ● (N_Ed, |M_Ed|) applied · ▲ M_Rd at N_Ed

7 — Capacity Check

N_Edapplied axial force—kN

M_Edapplied moment—kNm

M_Rdcapacity at N_Ed—kNm

N_Rd,maxmax compression cap.—kN

UC= |M_Ed| / M_Rd—

Limit: UC ≤ 1.00 (horizontal envelope slice at N_Ed)

Unity Check UC = |M_Ed| / M_Rd(N_Ed)

—

Check status

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EN 1992-1-1:2004/AC:2010 (Eurocode 2). Interaction envelope by fibre integration: 300 concrete strips b×(h/300) mm, parabolic-rectangular σ–ε per §3.1.5 (ε_cu2 = 3.5 ‰, ε_c2 = 2.0 ‰, n = 2). Steel: bilinear elastic-perfectly plastic, E_s = 200 GPa, capped at ±f_yd. Yield strain ε_sy = f_yd/E_s. Three strain domains: (i) bending — ε_cu2 fixed at compression face, NA sweeps 0→h; (ii) full-compression transition; (iii) approach to uniform ε_c2. M_Rd found by horizontal slice of the envelope at N_Ed. Sign: N < 0 = compression · z > 0 = compression face · M > 0 = compression at +z.

RC Wall — Axial Force + Bending Capacity (N + My)

RC Wall — Axial Force + Bending Capacity (N + M_y)